Allow to specify the options as a function, which returns array in form

of (label, value) tuple in the SelectControl.

We will apply the transform function, while rendering the control, and
not during intialization. This will allow us to generate different
options data based on the dependent values.

web/pgadmin/browser/static/js/node.ui.js

@@ -77,13 +77,10 @@ function($, _, pgAdmin, Backbone, Backform, Alertify, Node) {
          */
         transform = this.field.get('transform') || self.defaults.transform;
         if (transform && _.isFunction(transform)) {
-          try {
-            data = transform.apply(self, [data]);
-          } catch(e) {
-            // Do nothing
-            data = []
-            m.trigger('pgadmin-view:transform:error', m, self.field, e);
-          }
+          // We will transform the data later, when rendering.
+          // It will allow us to generate different data based on the
+          // dependencies.
+          self.field.set('options', transform.bind(self, data));
         }
         self.field.set('options', data);
       }

web/pgadmin/static/js/backform.pgadmin.js

@@ -156,6 +156,57 @@
     });
   };
 
+  /*
+   * Overriding the render function of the select control to allow us to use
+   * options as function, which should return array in the format of
+   * (label, value) pair.
+   */
+  Backform.SelectControl.prototype.render = function() {
+    var field = _.defaults(this.field.toJSON(), this.defaults),
+      attributes = this.model.toJSON(),
+      attrArr = field.name.split('.'),
+      name = attrArr.shift(),
+      path = attrArr.join('.'),
+      rawValue = this.keyPathAccessor(attributes[name], path),
+      data = _.extend(field, {
+        rawValue: rawValue,
+        value: this.formatter.fromRaw(rawValue, this.model),
+        attributes: attributes,
+        formatter: this.formatter
+      }),
+      evalF = function(f, m) {
+        return (_.isFunction(f) ? !!f(m) : !!f);
+      };
+
+    // Evaluate the disabled, visible, and required option
+    _.extend(data, {
+      disabled: evalF(data.disabled, this.model),
+      visible:  evalF(data.visible, this.model),
+      required: evalF(data.required, this.model)
+    });
+    // Evaluation the options
+    if (_.isFunction(data.options)) {
+      try {
+        data.options = data.options.apply(this)
+      } catch(e) {
+        // Do nothing
+        data = []
+        this.model.trigger('pgadmin-view:transform:error', m, self.field, e);
+      }
+    }
+
+    // Clean up first
+    this.$el.removeClass(Backform.hiddenClassname);
+
+    if (!data.visible)
+      this.$el.addClass(Backform.hiddenClassname);
+
+    this.$el.html(this.template(data)).addClass(field.name);
+    this.updateInvalid();
+
+    return this;
+  };
+
   var ReadonlyOptionControl = Backform.ReadonlyOptionControl = Backform.SelectControl.extend({
     template: _.template([
       '<label class="<%=Backform.controlLabelClassName%>"><%=label%></label>',