addons/point_of_sale/static/src/js/models.js

   1 function openerp_pos_models(instance, module){ //module is instance.point_of_sale
   2     var QWeb = instance.web.qweb;
   3         var _t = instance.web._t;
   4
   5     var round_di = instance.web.round_decimals;
   6     var round_pr = instance.web.round_precision
   7
   8     // The PosModel contains the Point Of Sale's representation of the backend.
   9     // Since the PoS must work in standalone ( Without connection to the server )
  10     // it must contains a representation of the server's PoS backend.
  11     // (taxes, product list, configuration options, etc.)  this representation
  12     // is fetched and stored by the PosModel at the initialisation.
  13     // this is done asynchronously, a ready deferred alows the GUI to wait interactively
  14     // for the loading to be completed
  15     // There is a single instance of the PosModel for each Front-End instance, it is usually called
  16     // 'pos' and is available to all widgets extending PosWidget.
  17
  18     module.PosModel = Backbone.Model.extend({
  19         initialize: function(session, attributes) {
  20             Backbone.Model.prototype.initialize.call(this, attributes);
  21             var  self = this;
  22             this.session = session;
  23             this.flush_mutex = new $.Mutex();                   // used to make sure the orders are sent to the server once at time
  24             this.pos_widget = attributes.pos_widget;
  25
  26             this.proxy = new module.ProxyDevice(this);              // used to communicate to the hardware devices via a local proxy
  27             this.barcode_reader = new module.BarcodeReader({'pos': this, proxy:this.proxy, patterns: {}});  // used to read barcodes
  28             this.proxy_queue = new module.JobQueue();           // used to prevent parallels communications to the proxy
  29             this.db = new module.PosDB();                       // a local database used to search trough products and categories & store pending orders
  30             this.debug = jQuery.deparam(jQuery.param.querystring()).debug !== undefined;    //debug mode
  31
  32             // Business data; loaded from the server at launch
  33             this.accounting_precision = 2; //TODO
  34             this.company_logo = null;
  35             this.company_logo_base64 = '';
  36             this.currency = null;
  37             this.shop = null;
  38             this.company = null;
  39             this.user = null;
  40             this.users = [];
  41             this.partners = [];
  42             this.cashier = null;
  43             this.cashregisters = [];
  44             this.bankstatements = [];
  45             this.taxes = [];
  46             this.pos_session = null;
  47             this.config = null;
  48             this.units = [];
  49             this.units_by_id = {};
  50             this.pricelist = null;
  51             this.order_sequence = 1;
  52             window.posmodel = this;
  53
  54             // these dynamic attributes can be watched for change by other models or widgets
  55             this.set({
  56                 'synch':            { state:'connected', pending:0 },
  57                 'orders':           new module.OrderCollection(),
  58                 'selectedOrder':    null,
  59             });
  60
  61             this.bind('change:synch',function(pos,synch){
  62                 clearTimeout(self.synch_timeout);
  63                 self.synch_timeout = setTimeout(function(){
  64                     if(synch.state !== 'disconnected' && synch.pending > 0){
  65                         self.set('synch',{state:'disconnected', pending:synch.pending});
  66                     }
  67                 },3000);
  68             });
  69
  70             this.get('orders').bind('remove', function(order,_unused_,options){
  71                 self.on_removed_order(order,options.index,options.reason);
  72             });
  73
  74             // We fetch the backend data on the server asynchronously. this is done only when the pos user interface is launched,
  75             // Any change on this data made on the server is thus not reflected on the point of sale until it is relaunched.
  76             // when all the data has loaded, we compute some stuff, and declare the Pos ready to be used.
  77             this.ready = this.load_server_data()
  78                 .then(function(){
  79                     if(self.config.use_proxy){
  80                         return self.connect_to_proxy();
  81                     }
  82                 });
  83
  84         },
  85
  86         // releases ressources holds by the model at the end of life of the posmodel
  87         destroy: function(){
  88             // FIXME, should wait for flushing, return a deferred to indicate successfull destruction
  89             // this.flush();
  90             this.proxy.close();
  91             this.barcode_reader.disconnect();
  92             this.barcode_reader.disconnect_from_proxy();
  93         },
  94         connect_to_proxy: function(){
  95             var self = this;
  96             var  done = new $.Deferred();
  97             this.barcode_reader.disconnect_from_proxy();
  98             this.pos_widget.loading_message(_t('Connecting to the PosBox'),0);
  99             this.pos_widget.loading_skip(function(){
 100                     self.proxy.stop_searching();
 101                 });
 102             this.proxy.autoconnect({
 103                     force_ip: self.config.proxy_ip || undefined,
 104                     progress: function(prog){
 105                         self.pos_widget.loading_progress(prog);
 106                     },
 107                 }).then(function(){
 108                     if(self.config.iface_scan_via_proxy){
 109                         self.barcode_reader.connect_to_proxy();
 110                     }
 111                 }).always(function(){
 112                     done.resolve();
 113                 });
 114             return done;
 115         },
 116
 117         // helper function to load data from the server. Obsolete use the models loader below.
 118         fetch: function(model, fields, domain, ctx){
 119             this._load_progress = (this._load_progress || 0) + 0.05;
 120             this.pos_widget.loading_message(_t('Loading')+' '+model,this._load_progress);
 121             return new instance.web.Model(model).query(fields).filter(domain).context(ctx).all()
 122         },
 123
 124         // Server side model loaders. This is the list of the models that need to be loaded from
 125         // the server. The models are loaded one by one by this list's order. The 'loaded' callback
 126         // is used to store the data in the appropriate place once it has been loaded. This callback
 127         // can return a deferred that will pause the loading of the next module.
 128         // a shared temporary dictionary is available for loaders to communicate private variables
 129         // used during loading such as object ids, etc.
 130         models: [
 131         {
 132             model:  'res.users',
 133             fields: ['name','company_id'],
 134             ids:    function(self){ return [self.session.uid]; },
 135             loaded: function(self,users){ self.user = users[0]; },
 136         },{
 137             model:  'res.company',
 138             fields: [ 'currency_id', 'email', 'website', 'company_registry', 'vat', 'name', 'phone', 'partner_id' , 'country_id'],
 139             ids:    function(self){ return [self.user.company_id[0]] },
 140             loaded: function(self,companies){ self.company = companies[0]; },
 141         },{
 142             model:  'decimal.precision',
 143             fields: ['name','digits'],
 144             loaded: function(self,dps){
 145                 self.dp  = {};
 146                 for (var i = 0; i < dps.length; i++) {
 147                     self.dp[dps[i].name] = dps[i].digits;
 148                 }
 149             },
 150         },{
 151             model:  'product.uom',
 152             fields: [],
 153             domain: null,
 154             loaded: function(self,units){
 155                 self.units = units;
 156                 var units_by_id = {};
 157                 for(var i = 0, len = units.length; i < len; i++){
 158                     units_by_id[units[i].id] = units[i];
 159                     units[i].groupable = ( units[i].category_id[0] === 1 );
 160                     units[i].is_unit   = ( units[i].id === 1 );
 161                 }
 162                 self.units_by_id = units_by_id;
 163             }
 164         },{
 165             model:  'res.users',
 166             fields: ['name','ean13'],
 167             domain: null,
 168             loaded: function(self,users){ self.users = users; },
 169         },{
 170             model:  'res.partner',
 171             fields: ['name','street','city','state_id','country_id','vat','phone','zip','mobile','email','ean13','write_date'],
 172             domain: null,
 173             loaded: function(self,partners){
 174                 self.partners = partners;
 175                 self.db.add_partners(partners);
 176             },
 177         },{
 178             model:  'res.country',
 179             fields: ['name'],
 180             loaded: function(self,countries){
 181                 self.countries = countries;
 182                 self.company.country = null;
 183                 for (var i = 0; i < countries.length; i++) {
 184                     if (countries[i].id === self.company.country_id[0]){
 185                         self.company.country = countries[i];
 186                     }
 187                 }
 188             },
 189         },{
 190             model:  'account.tax',
 191             fields: ['name','amount', 'price_include', 'type'],
 192             domain: null,
 193             loaded: function(self,taxes){ self.taxes = taxes; },
 194         },{
 195             model:  'pos.session',
 196             fields: ['id', 'journal_ids','name','user_id','config_id','start_at','stop_at','sequence_number','login_number'],
 197             domain: function(self){ return [['state','=','opened'],['user_id','=',self.session.uid]]; },
 198             loaded: function(self,pos_sessions){
 199                 self.pos_session = pos_sessions[0];
 200
 201                 var orders = self.db.get_orders();
 202                 for (var i = 0; i < orders.length; i++) {
 203                     self.pos_session.sequence_number = Math.max(self.pos_session.sequence_number, orders[i].data.sequence_number+1);
 204                 }
 205             },
 206         },{
 207             model: 'pos.config',
 208             fields: [],
 209             domain: function(self){ return [['id','=', self.pos_session.config_id[0]]]; },
 210             loaded: function(self,configs){
 211                 self.config = configs[0];
 212                 self.config.use_proxy = self.config.iface_payment_terminal ||
 213                                         self.config.iface_electronic_scale ||
 214                                         self.config.iface_print_via_proxy  ||
 215                                         self.config.iface_scan_via_proxy   ||
 216                                         self.config.iface_cashdrawer;
 217
 218                 self.barcode_reader.add_barcode_patterns({
 219                     'product':  self.config.barcode_product,
 220                     'cashier':  self.config.barcode_cashier,
 221                     'client':   self.config.barcode_customer,
 222                     'weight':   self.config.barcode_weight,
 223                     'discount': self.config.barcode_discount,
 224                     'price':    self.config.barcode_price,
 225                 });
 226
 227                 if (self.config.company_id[0] !== self.user.company_id[0]) {
 228                     throw new Error(_t("Error: The Point of Sale User must belong to the same company as the Point of Sale. You are probably trying to load the point of sale as an administrator in a multi-company setup, with the administrator account set to the wrong company."));
 229                 }
 230             },
 231         },{
 232             model: 'stock.location',
 233             fields: [],
 234             ids:    function(self){ return [self.config.stock_location_id[0]]; },
 235             loaded: function(self, locations){ self.shop = locations[0]; },
 236         },{
 237             model:  'product.pricelist',
 238             fields: ['currency_id'],
 239             ids:    function(self){ return [self.config.pricelist_id[0]]; },
 240             loaded: function(self, pricelists){ self.pricelist = pricelists[0]; },
 241         },{
 242             model: 'res.currency',
 243             fields: ['symbol','position','rounding','accuracy'],
 244             ids:    function(self){ return [self.pricelist.currency_id[0]]; },
 245             loaded: function(self, currencies){
 246                 self.currency = currencies[0];
 247                 if (self.currency.rounding > 0) {
 248                     self.currency.decimals = Math.ceil(Math.log(1.0 / self.currency.rounding) / Math.log(10));
 249                 } else {
 250                     self.currency.decimals = 0;
 251                 }
 252
 253             },
 254         },{
 255             model: 'product.packaging',
 256             fields: ['ean','product_tmpl_id'],
 257             domain: null,
 258             loaded: function(self, packagings){
 259                 self.db.add_packagings(packagings);
 260             },
 261         },{
 262             model:  'pos.category',
 263             fields: ['id','name','parent_id','child_id','image'],
 264             domain: null,
 265             loaded: function(self, categories){
 266                 self.db.add_categories(categories);
 267             },
 268         },{
 269             model:  'product.product',
 270             fields: ['display_name', 'list_price','price','pos_categ_id', 'taxes_id', 'ean13', 'default_code',
 271                      'to_weight', 'uom_id', 'uos_id', 'uos_coeff', 'mes_type', 'description_sale', 'description',
 272                      'product_tmpl_id'],
 273             domain:  function(self){ return [['sale_ok','=',true],['available_in_pos','=',true]]; },
 274             context: function(self){ return { pricelist: self.pricelist.id, display_default_code: false }; },
 275             loaded: function(self, products){
 276                 self.db.add_products(products);
 277             },
 278         },{
 279             model:  'account.bank.statement',
 280             fields: ['account_id','currency','journal_id','state','name','user_id','pos_session_id'],
 281             domain: function(self){ return [['state', '=', 'open'],['pos_session_id', '=', self.pos_session.id]]; },
 282             loaded: function(self, bankstatements, tmp){
 283                 self.bankstatements = bankstatements;
 284
 285                 tmp.journals = [];
 286                 _.each(bankstatements,function(statement){
 287                     tmp.journals.push(statement.journal_id[0]);
 288                 });
 289             },
 290         },{
 291             model:  'account.journal',
 292             fields: [],
 293             domain: function(self,tmp){ return [['id','in',tmp.journals]]; },
 294             loaded: function(self, journals){
 295                 self.journals = journals;
 296
 297                 // associate the bank statements with their journals.
 298                 var bankstatements = self.bankstatements;
 299                 for(var i = 0, ilen = bankstatements.length; i < ilen; i++){
 300                     for(var j = 0, jlen = journals.length; j < jlen; j++){
 301                         if(bankstatements[i].journal_id[0] === journals[j].id){
 302                             bankstatements[i].journal = journals[j];
 303                         }
 304                     }
 305                 }
 306                 self.cashregisters = bankstatements;
 307             },
 308         },{
 309             label: 'fonts',
 310             loaded: function(self){
 311                 var fonts_loaded = new $.Deferred();
 312                 // Waiting for fonts to be loaded to prevent receipt printing
 313                 // from printing empty receipt while loading Inconsolata
 314                 // ( The font used for the receipt )
 315                 waitForWebfonts(['Lato','Inconsolata'], function(){
 316                     fonts_loaded.resolve();
 317                 });
 318                 // The JS used to detect font loading is not 100% robust, so
 319                 // do not wait more than 5sec
 320                 setTimeout(function(){
 321                     fonts_loaded.resolve();
 322                 },5000);
 323
 324                 return fonts_loaded;
 325             },
 326         },{
 327             label: 'pictures',
 328             loaded: function(self){
 329                 self.company_logo = new Image();
 330                 var  logo_loaded = new $.Deferred();
 331                 self.company_logo.onload = function(){
 332                     var img = self.company_logo;
 333                     var ratio = 1;
 334                     var targetwidth = 300;
 335                     var maxheight = 150;
 336                     if( img.width !== targetwidth ){
 337                         ratio = targetwidth / img.width;
 338                     }
 339                     if( img.height * ratio > maxheight ){
 340                         ratio = maxheight / img.height;
 341                     }
 342                     var width  = Math.floor(img.width * ratio);
 343                     var height = Math.floor(img.height * ratio);
 344                     var c = document.createElement('canvas');
 345                         c.width  = width;
 346                         c.height = height
 347                     var ctx = c.getContext('2d');
 348                         ctx.drawImage(self.company_logo,0,0, width, height);
 349
 350                     self.company_logo_base64 = c.toDataURL();
 351                     logo_loaded.resolve();
 352                 };
 353                 self.company_logo.onerror = function(){
 354                     logo_loaded.reject();
 355                 };
 356                     self.company_logo.crossOrigin = "anonymous";
 357                 self.company_logo.src = '/web/binary/company_logo' +'?_'+Math.random();
 358
 359                 return logo_loaded;
 360             },
 361         },
 362         ],
 363
 364         // loads all the needed data on the sever. returns a deferred indicating when all the data has loaded.
 365         load_server_data: function(){
 366             var self = this;
 367             var loaded = new $.Deferred();
 368             var progress = 0;
 369             var progress_step = 1.0 / self.models.length;
 370             var tmp = {}; // this is used to share a temporary state between models loaders
 371
 372             function load_model(index){
 373                 if(index >= self.models.length){
 374                     loaded.resolve();
 375                 }else{
 376                     var model = self.models[index];
 377                     self.pos_widget.loading_message(_t('Loading')+' '+(model.label || model.model || ''), progress);
 378                     var fields =  typeof model.fields === 'function'  ? model.fields(self,tmp)  : model.fields;
 379                     var domain =  typeof model.domain === 'function'  ? model.domain(self,tmp)  : model.domain;
 380                     var context = typeof model.context === 'function' ? model.context(self,tmp) : model.context;
 381                     var ids     = typeof model.ids === 'function'     ? model.ids(self,tmp) : model.ids;
 382                     progress += progress_step;
 383
 384
 385                     if( model.model ){
 386                         if (model.ids) {
 387                             var records = new instance.web.Model(model.model).call('read',[ids,fields],context);
 388                         } else {
 389                             var records = new instance.web.Model(model.model).query(fields).filter(domain).context(context).all()
 390                         }
 391                         records.then(function(result){
 392                                 try{    // catching exceptions in model.loaded(...)
 393                                     $.when(model.loaded(self,result,tmp))
 394                                         .then(function(){ load_model(index + 1); },
 395                                               function(err){ loaded.reject(err); });
 396                                 }catch(err){
 397                                     console.error(err.stack);
 398                                     loaded.reject(err);
 399                                 }
 400                             },function(err){
 401                                 loaded.reject(err);
 402                             });
 403                     }else if( model.loaded ){
 404                         try{    // catching exceptions in model.loaded(...)
 405                             $.when(model.loaded(self,tmp))
 406                                 .then(  function(){ load_model(index +1); },
 407                                         function(err){ loaded.reject(err); });
 408                         }catch(err){
 409                             loaded.reject(err);
 410                         }
 411                     }else{
 412                         load_model(index + 1);
 413                     }
 414                 }
 415             }
 416
 417             try{
 418                 load_model(0);
 419             }catch(err){
 420                 loaded.reject(err);
 421             }
 422
 423             return loaded;
 424         },
 425
 426         // reload the list of partner, returns as a deferred that resolves if there were
 427         // updated partners, and fails if not
 428         load_new_partners: function(){
 429             var self = this;
 430             var def  = new $.Deferred();
 431             var fields = _.find(this.models,function(model){ return model.model === 'res.partner'; }).fields;
 432             new instance.web.Model('res.partner')
 433                 .query(fields)
 434                 .filter([['write_date','>',this.db.get_partner_write_date()]])
 435                 .all({'timeout':3000, 'shadow': true})
 436                 .then(function(partners){
 437                     if (self.db.add_partners(partners)) {   // check if the partners we got were real updates
 438                         def.resolve();
 439                     } else {
 440                         def.reject();
 441                     }
 442                 }, function(){ def.reject(); });
 443             return def;
 444         },
 445
 446         // this is called when an order is removed from the order collection. It ensures that there is always an existing
 447         // order and a valid selected order
 448         on_removed_order: function(removed_order,index,reason){
 449             if( (reason === 'abandon' || removed_order.temporary) && this.get('orders').size() > 0){
 450                 // when we intentionally remove an unfinished order, and there is another existing one
 451                 this.set({'selectedOrder' : this.get('orders').at(index) || this.get('orders').last()});
 452             }else{
 453                 // when the order was automatically removed after completion,
 454                 // or when we intentionally delete the only concurrent order
 455                 this.add_new_order();
 456             }
 457         },
 458
 459         //creates a new empty order and sets it as the current order
 460         add_new_order: function(){
 461             var order = new module.Order({pos:this});
 462             this.get('orders').add(order);
 463             this.set('selectedOrder', order);
 464         },
 465
 466         get_order: function(){
 467             return this.get('selectedOrder');
 468         },
 469
 470         //removes the current order
 471         delete_current_order: function(){
 472             this.get('selectedOrder').destroy({'reason':'abandon'});
 473         },
 474
 475         // saves the order locally and try to send it to the backend.
 476         // it returns a deferred that succeeds after having tried to send the order and all the other pending orders.
 477         push_order: function(order) {
 478             var self = this;
 479
 480             if(order){
 481                 this.proxy.log('push_order',order.export_as_JSON());
 482                 this.db.add_order(order.export_as_JSON());
 483             }
 484
 485             var pushed = new $.Deferred();
 486
 487             this.flush_mutex.exec(function(){
 488                 var flushed = self._flush_orders(self.db.get_orders());
 489
 490                 flushed.always(function(ids){
 491                     pushed.resolve();
 492                 });
 493             });
 494             return pushed;
 495         },
 496
 497         // saves the order locally and try to send it to the backend and make an invoice
 498         // returns a deferred that succeeds when the order has been posted and successfully generated
 499         // an invoice. This method can fail in various ways:
 500         // error-no-client: the order must have an associated partner_id. You can retry to make an invoice once
 501         //     this error is solved
 502         // error-transfer: there was a connection error during the transfer. You can retry to make the invoice once
 503         //     the network connection is up
 504
 505         push_and_invoice_order: function(order){
 506             var self = this;
 507             var invoiced = new $.Deferred();
 508
 509             if(!order.get_client()){
 510                 invoiced.reject('error-no-client');
 511                 return invoiced;
 512             }
 513
 514             var order_id = this.db.add_order(order.export_as_JSON());
 515
 516             this.flush_mutex.exec(function(){
 517                 var done = new $.Deferred(); // holds the mutex
 518
 519                 // send the order to the server
 520                 // we have a 30 seconds timeout on this push.
 521                 // FIXME: if the server takes more than 30 seconds to accept the order,
 522                 // the client will believe it wasn't successfully sent, and very bad
 523                 // things will happen as a duplicate will be sent next time
 524                 // so we must make sure the server detects and ignores duplicated orders
 525
 526                 var transfer = self._flush_orders([self.db.get_order(order_id)], {timeout:30000, to_invoice:true});
 527
 528                 transfer.fail(function(){
 529                     invoiced.reject('error-transfer');
 530                     done.reject();
 531                 });
 532
 533                 // on success, get the order id generated by the server
 534                 transfer.pipe(function(order_server_id){
 535
 536                     // generate the pdf and download it
 537                     self.pos_widget.do_action('point_of_sale.pos_invoice_report',{additional_context:{
 538                         active_ids:order_server_id,
 539                     }});
 540
 541                     invoiced.resolve();
 542                     done.resolve();
 543                 });
 544
 545                 return done;
 546
 547             });
 548
 549             return invoiced;
 550         },
 551
 552         // wrapper around the _save_to_server that updates the synch status widget
 553         _flush_orders: function(orders, options) {
 554             var self = this;
 555             this.set('synch',{ state: 'connecting', pending: orders.length});
 556
 557             return self._save_to_server(orders, options).done(function (server_ids) {
 558                 var pending = self.db.get_orders().length;
 559
 560                 self.set('synch', {
 561                     state: pending ? 'connecting' : 'connected',
 562                     pending: pending
 563                 });
 564
 565                 return server_ids;
 566             });
 567         },
 568
 569         // send an array of orders to the server
 570         // available options:
 571         // - timeout: timeout for the rpc call in ms
 572         // returns a deferred that resolves with the list of
 573         // server generated ids for the sent orders
 574         _save_to_server: function (orders, options) {
 575             if (!orders || !orders.length) {
 576                 var result = $.Deferred();
 577                 result.resolve([]);
 578                 return result;
 579             }
 580
 581             options = options || {};
 582
 583             var self = this;
 584             var timeout = typeof options.timeout === 'number' ? options.timeout : 7500 * orders.length;
 585
 586             // we try to send the order. shadow prevents a spinner if it takes too long. (unless we are sending an invoice,
 587             // then we want to notify the user that we are waiting on something )
 588             var posOrderModel = new instance.web.Model('pos.order');
 589             return posOrderModel.call('create_from_ui',
 590                 [_.map(orders, function (order) {
 591                     order.to_invoice = options.to_invoice || false;
 592                     return order;
 593                 })],
 594                 undefined,
 595                 {
 596                     shadow: !options.to_invoice,
 597                     timeout: timeout
 598                 }
 599             ).then(function (server_ids) {
 600                 _.each(orders, function (order) {
 601                     self.db.remove_order(order.id);
 602                 });
 603                 return server_ids;
 604             }).fail(function (error, event){
 605                 if(error.code === 200 ){    // Business Logic Error, not a connection problem
 606                     //if warning do not need to dispaly traceback!!
 607                     if(error.data.exception_type == 'warning'){
 608                         delete error.data.debug;
 609                     }
 610                     self.pos_widget.screen_selector.show_popup('error-traceback',{
 611                         message: error.data.message,
 612                         comment: error.data.debug
 613                     });
 614                 }
 615                 // prevent an error popup creation by the rpc failure
 616                 // we want the failure to be silent as we send the orders in the background
 617                 event.preventDefault();
 618                 console.error('Failed to send orders:', orders);
 619             });
 620         },
 621
 622         scan_product: function(parsed_code){
 623             var self = this;
 624             var selectedOrder = this.get('selectedOrder');
 625             if(parsed_code.encoding === 'ean13'){
 626                 var product = this.db.get_product_by_ean13(parsed_code.base_code);
 627             }else if(parsed_code.encoding === 'reference'){
 628                 var product = this.db.get_product_by_reference(parsed_code.code);
 629             }
 630
 631             if(!product){
 632                 return false;
 633             }
 634
 635             if(parsed_code.type === 'price'){
 636                 selectedOrder.addProduct(product, {price:parsed_code.value});
 637             }else if(parsed_code.type === 'weight'){
 638                 selectedOrder.addProduct(product, {quantity:parsed_code.value, merge:false});
 639             }else if(parsed_code.type === 'discount'){
 640                 selectedOrder.addProduct(product, {discount:parsed_code.value, merge:false});
 641             }else{
 642                 selectedOrder.addProduct(product);
 643             }
 644             return true;
 645         },
 646     });
 647
 648     var orderline_id = 1;
 649
 650     // An orderline represent one element of the content of a client's shopping cart.
 651     // An orderline contains a product, its quantity, its price, discount. etc.
 652     // An Order contains zero or more Orderlines.
 653     module.Orderline = Backbone.Model.extend({
 654         initialize: function(attr,options){
 655             this.pos = options.pos;
 656             this.order = options.order;
 657             this.product = options.product;
 658             this.price   = options.product.price;
 659             this.quantity = 1;
 660             this.quantityStr = '1';
 661             this.discount = 0;
 662             this.discountStr = '0';
 663             this.type = 'unit';
 664             this.selected = false;
 665             this.id       = orderline_id++;
 666         },
 667         clone: function(){
 668             var orderline = new module.Orderline({},{
 669                 pos: this.pos,
 670                 order: null,
 671                 product: this.product,
 672                 price: this.price,
 673             });
 674             orderline.quantity = this.quantity;
 675             orderline.quantityStr = this.quantityStr;
 676             orderline.discount = this.discount;
 677             orderline.type = this.type;
 678             orderline.selected = false;
 679             return orderline;
 680         },
 681         // sets a discount [0,100]%
 682         set_discount: function(discount){
 683             var disc = Math.min(Math.max(parseFloat(discount) || 0, 0),100);
 684             this.discount = disc;
 685             this.discountStr = '' + disc;
 686             this.trigger('change',this);
 687         },
 688         // returns the discount [0,100]%
 689         get_discount: function(){
 690             return this.discount;
 691         },
 692         get_discount_str: function(){
 693             return this.discountStr;
 694         },
 695         get_product_type: function(){
 696             return this.type;
 697         },
 698         // sets the quantity of the product. The quantity will be rounded according to the
 699         // product's unity of measure properties. Quantities greater than zero will not get
 700         // rounded to zero
 701         set_quantity: function(quantity){
 702             if(quantity === 'remove'){
 703                 this.order.removeOrderline(this);
 704                 return;
 705             }else{
 706                 var quant = parseFloat(quantity) || 0;
 707                 var unit = this.get_unit();
 708                 if(unit){
 709                     if (unit.rounding) {
 710                         this.quantity    = round_pr(quant, unit.rounding);
 711                         this.quantityStr = this.quantity.toFixed(Math.ceil(Math.log(1.0 / unit.rounding) / Math.log(10)));
 712                     } else {
 713                         this.quantity    = round_pr(quant, 1);
 714                         this.quantityStr = this.quantity.toFixed(0);
 715                     }
 716                 }else{
 717                     this.quantity    = quant;
 718                     this.quantityStr = '' + this.quantity;
 719                 }
 720             }
 721             this.trigger('change',this);
 722         },
 723         // return the quantity of product
 724         get_quantity: function(){
 725             return this.quantity;
 726         },
 727         get_quantity_str: function(){
 728             return this.quantityStr;
 729         },
 730         get_quantity_str_with_unit: function(){
 731             var unit = this.get_unit();
 732             if(unit && !unit.is_unit){
 733                 return this.quantityStr + ' ' + unit.name;
 734             }else{
 735                 return this.quantityStr;
 736             }
 737         },
 738         // return the unit of measure of the product
 739         get_unit: function(){
 740             var unit_id = this.product.uom_id;
 741             if(!unit_id){
 742                 return undefined;
 743             }
 744             unit_id = unit_id[0];
 745             if(!this.pos){
 746                 return undefined;
 747             }
 748             return this.pos.units_by_id[unit_id];
 749         },
 750         // return the product of this orderline
 751         get_product: function(){
 752             return this.product;
 753         },
 754         // selects or deselects this orderline
 755         set_selected: function(selected){
 756             this.selected = selected;
 757             this.trigger('change',this);
 758         },
 759         // returns true if this orderline is selected
 760         is_selected: function(){
 761             return this.selected;
 762         },
 763         // when we add an new orderline we want to merge it with the last line to see reduce the number of items
 764         // in the orderline. This returns true if it makes sense to merge the two
 765         can_be_merged_with: function(orderline){
 766             if( this.get_product().id !== orderline.get_product().id){    //only orderline of the same product can be merged
 767                 return false;
 768             }else if(!this.get_unit() || !this.get_unit().groupable){
 769                 return false;
 770             }else if(this.get_product_type() !== orderline.get_product_type()){
 771                 return false;
 772             }else if(this.get_discount() > 0){             // we don't merge discounted orderlines
 773                 return false;
 774             }else if(this.price !== orderline.price){
 775                 return false;
 776             }else{
 777                 return true;
 778             }
 779         },
 780         merge: function(orderline){
 781             this.set_quantity(this.get_quantity() + orderline.get_quantity());
 782         },
 783         export_as_JSON: function() {
 784             return {
 785                 qty: this.get_quantity(),
 786                 price_unit: this.get_unit_price(),
 787                 discount: this.get_discount(),
 788                 product_id: this.get_product().id,
 789             };
 790         },
 791         //used to create a json of the ticket, to be sent to the printer
 792         export_for_printing: function(){
 793             return {
 794                 quantity:           this.get_quantity(),
 795                 unit_name:          this.get_unit().name,
 796                 price:              this.get_unit_price(),
 797                 discount:           this.get_discount(),
 798                 product_name:       this.get_product().display_name,
 799                 price_display :     this.get_display_price(),
 800                 price_with_tax :    this.get_price_with_tax(),
 801                 price_without_tax:  this.get_price_without_tax(),
 802                 tax:                this.get_tax(),
 803                 product_description:      this.get_product().description,
 804                 product_description_sale: this.get_product().description_sale,
 805             };
 806         },
 807         // changes the base price of the product for this orderline
 808         set_unit_price: function(price){
 809             this.price = round_di(parseFloat(price) || 0, this.pos.dp['Product Price']);
 810             this.trigger('change',this);
 811         },
 812         get_unit_price: function(){
 813             return this.price;
 814         },
 815         get_base_price:    function(){
 816             var rounding = this.pos.currency.rounding;
 817             return  round_pr(round_pr(this.get_unit_price() * this.get_quantity(),rounding) * (1- this.get_discount()/100.0),rounding);
 818         },
 819         get_display_price: function(){
 820             return this.get_base_price();
 821         },
 822         get_price_without_tax: function(){
 823             return this.get_all_prices().priceWithoutTax;
 824         },
 825         get_price_with_tax: function(){
 826             return this.get_all_prices().priceWithTax;
 827         },
 828         get_tax: function(){
 829             return this.get_all_prices().tax;
 830         },
 831         get_tax_details: function(){
 832             return this.get_all_prices().taxDetails;
 833         },
 834         get_all_prices: function(){
 835             var self = this;
 836             var currency_rounding = this.pos.currency.rounding;
 837             var base = this.get_base_price();
 838             var totalTax = base;
 839             var totalNoTax = base;
 840
 841             var product =  this.get_product();
 842             var taxes_ids = product.taxes_id;
 843             var taxes =  self.pos.taxes;
 844             var taxtotal = 0;
 845             var taxdetail = {};
 846             _.each(taxes_ids, function(el) {
 847                 var tax = _.detect(taxes, function(t) {return t.id === el;});
 848                 if (tax.price_include) {
 849                     var tmp;
 850                     if (tax.type === "percent") {
 851                         tmp =  base - round_pr(base / (1 + tax.amount),currency_rounding);
 852                     } else if (tax.type === "fixed") {
 853                         tmp = round_pr(tax.amount * self.get_quantity(),currency_rounding);
 854                     } else {
 855                         throw "This type of tax is not supported by the point of sale: " + tax.type;
 856                     }
 857                     tmp = round_pr(tmp,currency_rounding);
 858                     taxtotal += tmp;
 859                     totalNoTax -= tmp;
 860                     taxdetail[tax.id] = tmp;
 861                 } else {
 862                     var tmp;
 863                     if (tax.type === "percent") {
 864                         tmp = tax.amount * base;
 865                     } else if (tax.type === "fixed") {
 866                         tmp = tax.amount * self.get_quantity();
 867                     } else {
 868                         throw "This type of tax is not supported by the point of sale: " + tax.type;
 869                     }
 870                     tmp = round_pr(tmp,currency_rounding);
 871                     taxtotal += tmp;
 872                     totalTax += tmp;
 873                     taxdetail[tax.id] = tmp;
 874                 }
 875             });
 876             return {
 877                 "priceWithTax": totalTax,
 878                 "priceWithoutTax": totalNoTax,
 879                 "tax": taxtotal,
 880                 "taxDetails": taxdetail,
 881             };
 882         },
 883     });
 884
 885     module.OrderlineCollection = Backbone.Collection.extend({
 886         model: module.Orderline,
 887     });
 888
 889     // Every Paymentline contains a cashregister and an amount of money.
 890     module.Paymentline = Backbone.Model.extend({
 891         initialize: function(attributes, options) {
 892             this.amount = 0;
 893             this.cashregister = options.cashregister;
 894             this.name = this.cashregister.journal_id[1];
 895             this.selected = false;
 896             this.pos = options.pos;
 897         },
 898         //sets the amount of money on this payment line
 899         set_amount: function(value){
 900             this.amount = round_di(parseFloat(value) || 0, this.pos.currency.decimals);
 901             this.trigger('change:amount',this);
 902         },
 903         // returns the amount of money on this paymentline
 904         get_amount: function(){
 905             return this.amount;
 906         },
 907         get_amount_str: function(){
 908             return this.amount.toFixed(this.pos.currency.decimals);
 909         },
 910         set_selected: function(selected){
 911             if(this.selected !== selected){
 912                 this.selected = selected;
 913                 this.trigger('change:selected',this);
 914             }
 915         },
 916         // returns the associated cashregister
 917         //exports as JSON for server communication
 918         export_as_JSON: function(){
 919             return {
 920                 name: instance.web.datetime_to_str(new Date()),
 921                 statement_id: this.cashregister.id,
 922                 account_id: this.cashregister.account_id[0],
 923                 journal_id: this.cashregister.journal_id[0],
 924                 amount: this.get_amount()
 925             };
 926         },
 927         //exports as JSON for receipt printing
 928         export_for_printing: function(){
 929             return {
 930                 amount: this.get_amount(),
 931                 journal: this.cashregister.journal_id[1],
 932             };
 933         },
 934     });
 935
 936     module.PaymentlineCollection = Backbone.Collection.extend({
 937         model: module.Paymentline,
 938     });
 939
 940
 941     // An order more or less represents the content of a client's shopping cart (the OrderLines)
 942     // plus the associated payment information (the Paymentlines)
 943     // there is always an active ('selected') order in the Pos, a new one is created
 944     // automaticaly once an order is completed and sent to the server.
 945     module.Order = Backbone.Model.extend({
 946         initialize: function(attributes){
 947             Backbone.Model.prototype.initialize.apply(this, arguments);
 948             this.pos = attributes.pos;
 949             this.sequence_number = this.pos.pos_session.sequence_number++;
 950             this.uid =     this.generateUniqueId();
 951             this.set({
 952                 creationDate:   new Date(),
 953                 orderLines:     new module.OrderlineCollection(),
 954                 paymentLines:   new module.PaymentlineCollection(),
 955                 name:           _t("Order ") + this.uid,
 956                 client:         null,
 957             });
 958             this.selected_orderline   = undefined;
 959             this.selected_paymentline = undefined;
 960             this.screen_data = {};  // see ScreenSelector
 961             this.receipt_type = 'receipt';  // 'receipt' || 'invoice'
 962             this.temporary = attributes.temporary || false;
 963             this.to_invoice = false;
 964             return this;
 965         },
 966         is_empty: function(){
 967             return (this.get('orderLines').models.length === 0);
 968         },
 969         // Generates a public identification number for the order.
 970         // The generated number must be unique and sequential. They are made 12 digit long
 971         // to fit into EAN-13 barcodes, should it be needed
 972         generateUniqueId: function() {
 973             function zero_pad(num,size){
 974                 var s = ""+num;
 975                 while (s.length < size) {
 976                     s = "0" + s;
 977                 }
 978                 return s;
 979             }
 980             return zero_pad(this.pos.pos_session.id,5) +'-'+
 981                    zero_pad(this.pos.pos_session.login_number,3) +'-'+
 982                    zero_pad(this.sequence_number,4);
 983         },
 984         addOrderline: function(line){
 985             if(line.order){
 986                 order.removeOrderline(line);
 987             }
 988             line.order = this;
 989             this.get('orderLines').add(line);
 990             this.selectLine(this.getLastOrderline());
 991         },
 992         addProduct: function(product, options){
 993             options = options || {};
 994             var attr = JSON.parse(JSON.stringify(product));
 995             attr.pos = this.pos;
 996             attr.order = this;
 997             var line = new module.Orderline({}, {pos: this.pos, order: this, product: product});
 998
 999             if(options.quantity !== undefined){
1000                 line.set_quantity(options.quantity);
1001             }
1002             if(options.price !== undefined){
1003                 line.set_unit_price(options.price);
1004             }
1005             if(options.discount !== undefined){
1006                 line.set_discount(options.discount);
1007             }
1008
1009             var last_orderline = this.getLastOrderline();
1010             if( last_orderline && last_orderline.can_be_merged_with(line) && options.merge !== false){
1011                 last_orderline.merge(line);
1012             }else{
1013                 this.get('orderLines').add(line);
1014             }
1015             this.selectLine(this.getLastOrderline());
1016         },
1017         removeOrderline: function( line ){
1018             this.get('orderLines').remove(line);
1019             this.selectLine(this.getLastOrderline());
1020         },
1021         getOrderline: function(id){
1022             var orderlines = this.get('orderLines').models;
1023             for(var i = 0; i < orderlines.length; i++){
1024                 if(orderlines[i].id === id){
1025                     return orderlines[i];
1026                 }
1027             }
1028             return null;
1029         },
1030         getLastOrderline: function(){
1031             return this.get('orderLines').at(this.get('orderLines').length -1);
1032         },
1033         addPaymentline: function(cashregister) {
1034             var paymentLines = this.get('paymentLines');
1035             var newPaymentline = new module.Paymentline({},{cashregister:cashregister, pos:this.pos});
1036             if(cashregister.journal.type !== 'cash'){
1037                 newPaymentline.set_amount( Math.max(this.getDueLeft(),0) );
1038             }
1039             paymentLines.add(newPaymentline);
1040             this.selectPaymentline(newPaymentline);
1041
1042         },
1043         removePaymentline: function(line){
1044             if(this.selected_paymentline === line){
1045                 this.selectPaymentline(undefined);
1046             }
1047             this.get('paymentLines').remove(line);
1048         },
1049         getName: function() {
1050             return this.get('name');
1051         },
1052         getSubtotal : function(){
1053             return (this.get('orderLines')).reduce((function(sum, orderLine){
1054                 return sum + orderLine.get_display_price();
1055             }), 0);
1056         },
1057         getTotalTaxIncluded: function() {
1058             return (this.get('orderLines')).reduce((function(sum, orderLine) {
1059                 return sum + orderLine.get_price_with_tax();
1060             }), 0);
1061         },
1062         getDiscountTotal: function() {
1063             return (this.get('orderLines')).reduce((function(sum, orderLine) {
1064                 return sum + (orderLine.get_unit_price() * (orderLine.get_discount()/100) * orderLine.get_quantity());
1065             }), 0);
1066         },
1067         getTotalTaxExcluded: function() {
1068             return (this.get('orderLines')).reduce((function(sum, orderLine) {
1069                 return sum + orderLine.get_price_without_tax();
1070             }), 0);
1071         },
1072         getTax: function() {
1073             return (this.get('orderLines')).reduce((function(sum, orderLine) {
1074                 return sum + orderLine.get_tax();
1075             }), 0);
1076         },
1077         getTaxDetails: function(){
1078             var details = {};
1079             var fulldetails = [];
1080             var taxes_by_id = {};
1081
1082             for(var i = 0; i < this.pos.taxes.length; i++){
1083                 taxes_by_id[this.pos.taxes[i].id] = this.pos.taxes[i];
1084             }
1085
1086             this.get('orderLines').each(function(line){
1087                 var ldetails = line.get_tax_details();
1088                 for(var id in ldetails){
1089                     if(ldetails.hasOwnProperty(id)){
1090                         details[id] = (details[id] || 0) + ldetails[id];
1091                     }
1092                 }
1093             });
1094
1095             for(var id in details){
1096                 if(details.hasOwnProperty(id)){
1097                     fulldetails.push({amount: details[id], tax: taxes_by_id[id], name: taxes_by_id[id].name});
1098                 }
1099             }
1100
1101             return fulldetails;
1102         },
1103         getPaidTotal: function() {
1104             return (this.get('paymentLines')).reduce((function(sum, paymentLine) {
1105                 return sum + paymentLine.get_amount();
1106             }), 0);
1107         },
1108         getChange: function(paymentline) {
1109             if (!paymentline) {
1110                 var change = this.getPaidTotal() - this.getTotalTaxIncluded();
1111             } else {
1112                 var change = -this.getTotalTaxIncluded();
1113                 var lines  = this.get('paymentLines').models;
1114                 for (var i = 0; i < lines.length; i++) {
1115                     change += lines[i].get_amount();
1116                     if (lines[i] === paymentline) {
1117                         break;
1118                     }
1119                 }
1120             }
1121             return round_pr(Math.max(0,change), this.pos.currency.rounding);
1122         },
1123         getDueLeft: function(paymentline) {
1124             if (!paymentline) {
1125                 var due = this.getTotalTaxIncluded() - this.getPaidTotal();
1126             } else {
1127                 var due = this.getTotalTaxIncluded();
1128                 var lines = this.get('paymentLines').models;
1129                 for (var i = 0; i < lines.length; i++) {
1130                     if (lines[i] === paymentline) {
1131                         break;
1132                     } else {
1133                         due -= lines[i].get_amount();
1134                     }
1135                 }
1136             }
1137             return round_pr(Math.max(0,due), this.pos.currency.rounding);
1138         },
1139         isPaid: function(){
1140             return this.getDueLeft() === 0;
1141         },
1142         isPaidWithCash: function(){
1143             return !!this.get('paymentLines').find( function(pl){
1144                 return pl.cashregister.journal.type === 'cash';
1145             });
1146         },
1147         finalize: function(){
1148             this.destroy();
1149         },
1150         // sets the type of receipt 'receipt'(default) or 'invoice'
1151         set_receipt_type: function(type){
1152             this.receipt_type = type;
1153         },
1154         get_receipt_type: function(){
1155             return this.receipt_type;
1156         },
1157         // the client related to the current order.
1158         set_client: function(client){
1159             this.set('client',client);
1160         },
1161         get_client: function(){
1162             return this.get('client');
1163         },
1164         get_client_name: function(){
1165             var client = this.get('client');
1166             return client ? client.name : "";
1167         },
1168         // the order also stores the screen status, as the PoS supports
1169         // different active screens per order. This method is used to
1170         // store the screen status.
1171         set_screen_data: function(key,value){
1172             if(arguments.length === 2){
1173                 this.screen_data[key] = value;
1174             }else if(arguments.length === 1){
1175                 for(key in arguments[0]){
1176                     this.screen_data[key] = arguments[0][key];
1177                 }
1178             }
1179         },
1180         set_to_invoice: function(to_invoice) {
1181             this.to_invoice = to_invoice;
1182         },
1183         is_to_invoice: function(){
1184             return this.to_invoice;
1185         },
1186         // remove all the paymentlines with zero money in it
1187         clean_empty_paymentlines: function() {
1188             var lines = this.get('paymentLines').models;
1189             var empty = [];
1190             for ( var i = 0; i < lines.length; i++) {
1191                 if (!lines[i].get_amount()) {
1192                     empty.push(lines[i]);
1193                 }
1194             }
1195             for ( var i = 0; i < empty.length; i++) {
1196                 this.removePaymentline(empty[i]);
1197             }
1198         },
1199         //see set_screen_data
1200         get_screen_data: function(key){
1201             return this.screen_data[key];
1202         },
1203         // exports a JSON for receipt printing
1204         export_for_printing: function(){
1205             var orderlines = [];
1206             this.get('orderLines').each(function(orderline){
1207                 orderlines.push(orderline.export_for_printing());
1208             });
1209
1210             var paymentlines = [];
1211             this.get('paymentLines').each(function(paymentline){
1212                 paymentlines.push(paymentline.export_for_printing());
1213             });
1214             var client  = this.get('client');
1215             var cashier = this.pos.cashier || this.pos.user;
1216             var company = this.pos.company;
1217             var shop    = this.pos.shop;
1218             var date = new Date();
1219
1220             return {
1221                 orderlines: orderlines,
1222                 paymentlines: paymentlines,
1223                 subtotal: this.getSubtotal(),
1224                 total_with_tax: this.getTotalTaxIncluded(),
1225                 total_without_tax: this.getTotalTaxExcluded(),
1226                 total_tax: this.getTax(),
1227                 total_paid: this.getPaidTotal(),
1228                 total_discount: this.getDiscountTotal(),
1229                 tax_details: this.getTaxDetails(),
1230                 change: this.getChange(),
1231                 name : this.getName(),
1232                 client: client ? client.name : null ,
1233                 invoice_id: null,   //TODO
1234                 cashier: cashier ? cashier.name : null,
1235                 header: this.pos.config.receipt_header || '',
1236                 footer: this.pos.config.receipt_footer || '',
1237                 precision: {
1238                     price: 2,
1239                     money: 2,
1240                     quantity: 3,
1241                 },
1242                 date: {
1243                     year: date.getFullYear(),
1244                     month: date.getMonth(),
1245                     date: date.getDate(),       // day of the month
1246                     day: date.getDay(),         // day of the week
1247                     hour: date.getHours(),
1248                     minute: date.getMinutes() ,
1249                     isostring: date.toISOString(),
1250                     localestring: date.toLocaleString(),
1251                 },
1252                 company:{
1253                     email: company.email,
1254                     website: company.website,
1255                     company_registry: company.company_registry,
1256                     contact_address: company.partner_id[1],
1257                     vat: company.vat,
1258                     name: company.name,
1259                     phone: company.phone,
1260                     logo:  this.pos.company_logo_base64,
1261                 },
1262                 shop:{
1263                     name: shop.name,
1264                 },
1265                 currency: this.pos.currency,
1266             };
1267         },
1268         export_as_JSON: function() {
1269             var orderLines, paymentLines;
1270             orderLines = [];
1271             (this.get('orderLines')).each(_.bind( function(item) {
1272                 return orderLines.push([0, 0, item.export_as_JSON()]);
1273             }, this));
1274             paymentLines = [];
1275             (this.get('paymentLines')).each(_.bind( function(item) {
1276                 return paymentLines.push([0, 0, item.export_as_JSON()]);
1277             }, this));
1278             return {
1279                 name: this.getName(),
1280                 amount_paid: this.getPaidTotal(),
1281                 amount_total: this.getTotalTaxIncluded(),
1282                 amount_tax: this.getTax(),
1283                 amount_return: this.getChange(),
1284                 lines: orderLines,
1285                 statement_ids: paymentLines,
1286                 pos_session_id: this.pos.pos_session.id,
1287                 partner_id: this.get_client() ? this.get_client().id : false,
1288                 user_id: this.pos.cashier ? this.pos.cashier.id : this.pos.user.id,
1289                 uid: this.uid,
1290                 sequence_number: this.sequence_number,
1291             };
1292         },
1293         getSelectedLine: function(){
1294             return this.selected_orderline;
1295         },
1296         selectLine: function(line){
1297             if(line){
1298                 if(line !== this.selected_orderline){
1299                     if(this.selected_orderline){
1300                         this.selected_orderline.set_selected(false);
1301                     }
1302                     this.selected_orderline = line;
1303                     this.selected_orderline.set_selected(true);
1304                 }
1305             }else{
1306                 this.selected_orderline = undefined;
1307             }
1308         },
1309         deselectLine: function(){
1310             if(this.selected_orderline){
1311                 this.selected_orderline.set_selected(false);
1312                 this.selected_orderline = undefined;
1313             }
1314         },
1315         selectPaymentline: function(line){
1316             if(line !== this.selected_paymentline){
1317                 if(this.selected_paymentline){
1318                     this.selected_paymentline.set_selected(false);
1319                 }
1320                 this.selected_paymentline = line;
1321                 if(this.selected_paymentline){
1322                     this.selected_paymentline.set_selected(true);
1323                 }
1324                 this.trigger('change:selected_paymentline',this.selected_paymentline);
1325             }
1326         },
1327     });
1328
1329     module.OrderCollection = Backbone.Collection.extend({
1330         model: module.Order,
1331     });
1332
1333     /*
1334      The numpad handles both the choice of the property currently being modified
1335      (quantity, price or discount) and the edition of the corresponding numeric value.
1336      */
1337     module.NumpadState = Backbone.Model.extend({
1338         defaults: {
1339             buffer: "0",
1340             mode: "quantity"
1341         },
1342         appendNewChar: function(newChar) {
1343             var oldBuffer;
1344             oldBuffer = this.get('buffer');
1345             if (oldBuffer === '0') {
1346                 this.set({
1347                     buffer: newChar
1348                 });
1349             } else if (oldBuffer === '-0') {
1350                 this.set({
1351                     buffer: "-" + newChar
1352                 });
1353             } else {
1354                 this.set({
1355                     buffer: (this.get('buffer')) + newChar
1356                 });
1357             }
1358             this.trigger('set_value',this.get('buffer'));
1359         },
1360         deleteLastChar: function() {
1361             if(this.get('buffer') === ""){
1362                 if(this.get('mode') === 'quantity'){
1363                     this.trigger('set_value','remove');
1364                 }else{
1365                     this.trigger('set_value',this.get('buffer'));
1366                 }
1367             }else{
1368                 var newBuffer = this.get('buffer').slice(0,-1) || "";
1369                 this.set({ buffer: newBuffer });
1370                 this.trigger('set_value',this.get('buffer'));
1371             }
1372         },
1373         switchSign: function() {
1374             var oldBuffer;
1375             oldBuffer = this.get('buffer');
1376             this.set({
1377                 buffer: oldBuffer[0] === '-' ? oldBuffer.substr(1) : "-" + oldBuffer
1378             });
1379             this.trigger('set_value',this.get('buffer'));
1380         },
1381         changeMode: function(newMode) {
1382             this.set({
1383                 buffer: "0",
1384                 mode: newMode
1385             });
1386         },
1387         reset: function() {
1388             this.set({
1389                 buffer: "0",
1390                 mode: "quantity"
1391             });
1392         },
1393         resetValue: function(){
1394             this.set({buffer:'0'});
1395         },
1396     });
1397 }