title: Extjs variable in proxy api store using crud
body: <p>I would put a variable in my proxy api store (using crud) but it not work.</p>
  
  <p>The api config is an object , could you use a variable in object in javascript ?</p>
  
  <p>I use Sencha Architect and he format api...</p>
  
  <p>Do you have a suggest ?</p>
  
  <p>My base store :</p>
  
  <pre><code>Ext.define('ModuleGestion.store.Pays', {
      extend: 'Ext.data.Store',
  
      requires: [
          'ModuleGestion.model.Pays'
      ],
  
      constructor: function(cfg) {
          var me = this;
          cfg = cfg || {};
          me.callParent([Ext.apply({
              autoLoad: true,
              model: 'ModuleGestion.model.Pays',
              storeId: 'StorePays',
              proxy: {
                  type: 'ajax',
                  api: {
                      create: 'http://visual04/ModuleGestion/php/Pays.php?action=create',
                      read: 'http://visual04/ModuleGestion/php/Pays.php?action=read',
                      update: 'http://visual04/ModuleGestion/php/Pays.php?action=update',
                      destroy: 'http://visual04/ModuleGestion/php/Pays.php?action=destroy'
                  },
                  reader: {
                      type: 'json',
                      root: 'data'
                  },
                  writer: {
                      type: 'json',
                      root: 'data'
                  }
              }
          }, cfg)]);
      }
  });
  </code></pre>
  
  <p>My model with variable in api proxy</p>
  
  <pre><code>var Url = 'http://visual04/ModuleGestion/php/';
  var UrlPays = Url+'Pays.php';
  
  Ext.define('ModuleGestion.store.Pays', {
          extend: 'Ext.data.Store',
  
      requires: [
          'ModuleGestion.model.Pays'
      ],
  
      constructor: function(cfg) {
          var me = this;
          cfg = cfg || {};
          me.callParent([Ext.apply({
              autoLoad: true,
              model: 'ModuleGestion.model.Pays',
              storeId: 'StorePays',
              proxy: {
                  type: 'ajax',
                  api: '{\r\n    create: UrlPays+'action=create',\r\n    read: UrlPays+'action=read',\r\n    update: UrlPays+'action=update',\r\n    destroy: UrlPays+'action=destroy'\r\n}',
                  reader: {
                      type: 'json',
                      root: 'data'
                  },
                  writer: {
                      type: 'json',
                      root: 'data'
                  }
              }
          }, cfg)]);
      }
  });
  </code></pre>