Custom Model for ExtJS

custom_model.js

Ext.define("CustomRest", {
  extend: 'Ext.data.proxy.Rest',
  alias : 'proxy.customrest',
  
  setAction: function(config) {
    this[config.name] = function(model, options){
      
      Ext.apply(options, {
          records:[model],
          record: model,
          action : config.name
      });
      
      var scope = options.scope || model;
      var operation = new Ext.data.Operation(options);
      var callback = function(operation) {
        args = [model, operation];
        if (operation.wasSuccessful()) {
             Ext.callback(options.success, scope, args);
        } else {
            Ext.callback(options.failure, scope, args);
        }
        Ext.callback(options.callback, scope, args);
      };
      
      return this.doRequest.apply(this, [operation, callback]);
    };
    this.actionMethods[config.name] = config.method || "POST";
  },
  
  getAction: function(name) {
    return this.actions.filter(function(action) {
      return action.name === name;
    })[0];
  },
  
  pattern: /:(\w+)(?:(\(.*?\)))?(\?)?(\*)?/g,
  interpolate: function(url, model) {
    return url.replace(this.pattern, function(_, property) {
      return model.get(property);
    });    
  },
  
  buildUrl: function(request) {  
    var url = this.callParent(arguments);
   
    var action = this.getAction(request.action);
    if(action && action.url) {
      url = this.interpolate(action.url, request.operation.record) + ".json";
    }
   
    return url;
  },

  constructor: function(config) {

    this.actions = config.actions;    
    this.callParent([config]);

    if(config && config.actions) {
      for(action in config.actions) {
        this.setAction( config.actions[action] );
      }
    }

  }

});

Ext.define('CustomModel', {
  extend:'Ext.data.Model', 
  
  merge: function(fields) {
    for(var field in fields) {
      this.set(field, fields[field]);
    }
  },
  
  constructor: function() {
    this.callParent(arguments);
    
    this.setProxy({
      type: 'customrest',
      url: this.url,
      format: 'json',
      actions: this.actions
    });

    var self = this;
    if(self.actions) {
      for(position in self.actions) {
        var action = self.actions[position];
        self[action.name] = (function(act) {
          return function(options) {
            self.doAction(act, options);
          };
        })(action.name);
      }
    }
  	
  },
  doAction: function(action, options) {
    this.getProxy()[action](this, options);
  }
});

Ext.override(CustomModel, {
  statics: {
    load: function() {
      this.setProxy({
    		type: 'rest',
    		url: this.prototype.url,
    		format: 'json'
    	});
      this.callParent(arguments);
    }
  }
});

sistema.js

Ext.define('Sistema', {
  extend: 'CustomModel',
  fields: ['id','nome','cliente_id'],
  actions: [
  {
    name: "por_cliente",
    method: "GET",
    url: "/clientes/:cliente_id/sistemas/por_cliente"
  }
  ],
  url: "/sistemas"
});