sfSchema can communicate via sfRetainModel service to force the model…

… to ignore the destroyStrategy when the $destroy event occurs on sfSchema. This will prevent the data from being cleaned up when the form is removed from the DOM.

src/directives/schema-form.js

@@ -5,8 +5,8 @@ FIXME: real documentation
 
 angular.module('schemaForm')
        .directive('sfSchema',
-['$compile', 'schemaForm', 'schemaFormDecorators', 'sfSelect', 'sfPath',
-  function($compile,  schemaForm,  schemaFormDecorators, sfSelect, sfPath) {
+['$compile', 'schemaForm', 'schemaFormDecorators', 'sfSelect', 'sfPath', 'sfRetainModel',
+  function($compile,  schemaForm,  schemaFormDecorators, sfSelect, sfPath, sfRetainModel) {
 
     var SNAKE_CASE_REGEXP = /[A-Z]/g;
     var snakeCase = function(name, separator) {
@@ -161,6 +161,9 @@ angular.module('schemaForm')
           }
         });
 
+        scope.$on('$destroy', function() {
+          sfRetainModel.setFlag(true);
+        });
       }
     };
   }

src/directives/schema-validate.js

@@ -1,5 +1,5 @@
-angular.module('schemaForm').directive('schemaValidate', ['sfValidator', 'sfSelect', 'sfUnselect', '$parse',
-  function(sfValidator, sfSelect, sfUnselect, $parse) {
+angular.module('schemaForm').directive('schemaValidate', ['sfValidator', 'sfSelect', 'sfUnselect', '$parse', 'sfRetainModel',
+  function(sfValidator, sfSelect, sfUnselect, $parse, sfRetainModel) {
 
     return {
       restrict: 'A',
@@ -127,10 +127,13 @@ angular.module('schemaForm').directive('schemaValidate', ['sfValidator', 'sfSele
         // Clean up the model when the corresponding form field is $destroy-ed.
         // Default behavior can be supplied as a globalOption, and behavior can be overridden in the form definition.
         scope.$on('$destroy', function() {
+
           var form = getForm();
           var conditionResult = $parse(form.condition);
+          var formModelNotRetained = !sfRetainModel.getFlag();
 
-          if (form.hasOwnProperty('condition') && !conditionResult(scope)) { // If condition is defined and not satisfied.
+          // If condition is defined and not satisfied and the sfSchema model should not be retained.
+          if (form.hasOwnProperty('condition') && !conditionResult(scope) && formModelNotRetained) {
 
             // Either set in form definition, or as part of globalOptions.
             var destroyStrategy =

src/services/retainModel.js

@@ -0,0 +1,37 @@
+angular.module('schemaForm').factory('sfRetainModel', function() {
+
+  var data = {retainModelFlag: false };
+
+  return {
+    /**
+     * @description
+     * Utility service to indicate if the sfSchema model should be retained.
+     * Set to true to prevent an operation that would have destroyed the model
+     * from doing so (such as wrapping the form in an ng-if).
+     *
+     * ex.
+     * var foo = sfRetainModel.getFlag();
+     *
+     * @returns {boolean} returns the current value of the retainModelFlag.
+     */
+    getFlag: function () {
+      return data.retainModelFlag;
+    },
+
+    /**
+     * @description
+     * Set the value of the retainModelFlag.
+     * True prevents cleaning the data in the model, while false follows the configured destroyStrategy.
+     *
+     * ex.
+     * var bar = sfRetainModel.setFlag(true);
+     *
+     * @param {boolean} value  The boolean value to set as the retainModelFlag
+     * @returns {boolean} returns the value of the retainModelFlag after toggling.
+     */
+    setFlag: function(value) {
+      data.retainModelFlag = value;
+      return data.retainModelFlag;
+    }
+  }
+});