Update and refactor property models in Style Manager

src/style_manager/model/Property.js

@@ -1,70 +1,30 @@
-var Backbone = require('backbone');
-var Layers = require('./Layers');
-
-module.exports = Backbone.Model.extend({
+module.exports = require('backbone').Model.extend({
 
   defaults: {
     name: '',
     property: '',
     type: '',
-    units: [], // int
-    unit: '', // int
     defaults: '',
     info: '',
     value: '',
     icon: '',
-    preview: false, // stack
-    detached: false, // composite
-    visible: true,
     functionName: '',
     status: '',
-    properties: [], // composite
-    layers: [], // stack
-    list: [], // select/radio
+    visible: true,
     fixedValues: ['initial', 'inherit'],
   },
 
   initialize(opt) {
     var o = opt || {};
-    var type = this.get('type');
     var name = this.get('name');
     var prop = this.get('property');
-    var props = this.get('properties');
 
-    if(!name)
+    if (!name) {
       this.set('name', prop.charAt(0).toUpperCase() + prop.slice(1).replace(/-/g,' '));
-
-    if(props.length){
-      var Properties = require('./Properties');
-      this.set('properties', new Properties(props));
-    }
-
-    switch(type){
-      case 'stack':
-        this.set('layers', new Layers());
-        break;
-    }
-  },
-
-  /**
-   * Return value
-   * @return {string} Value
-   * @private
-   */
-  getValue() {
-    var result = '';
-    var type = this.get('type');
-
-    switch(type){
-      case 'integer':
-        result = this.get('value') + this.get('unit');
-        break;
-      default:
-        result = this.get('value');
-        break;
     }
 
-    return result;
+    const init = this.init && this.init.bind(this);
+    init && init();
   },
 
   /**

src/style_manager/model/PropertyComposite.js

@@ -18,6 +18,12 @@ module.exports = Property.extend({
     properties: [],
   }),
 
+  init() {
+    const properties = this.get('properties') || [];
+    const Properties = require('./Properties');
+    this.set('properties', new Properties(properties));
+  },
+
   getDefaultValue() {
     let value = this.get('defaults');
 

src/style_manager/model/PropertyStack.js

@@ -1,14 +1,22 @@
 const Property = require('./PropertyComposite');
+const Layers = require('./Layers');
 
 module.exports = Property.extend({
 
   defaults: Object.assign({}, Property.prototype.defaults, {
     // Array of layers (which contain properties)
     layers: [],
+
     // Layer preview
     preview: 0,
   }),
 
+  init() {
+    Property.prototype.init.apply(this, arguments);
+    const layers = this.get('layers');
+    this.set('layers', new Layers(layers));
+  },
+
   getFullValue() {
     if (this.get('detached')) {
       return '';