From b29aeff35f062c5adc189729191c8e8802a48384 Mon Sep 17 00:00:00 2001
From: Adrian Ber <beradrian@yahoo.com>
Date: Sat, 21 Nov 2015 21:46:21 +0200
Subject: [PATCH] checklistBeforeChange

---
 checklist-model.js          | 30 +++++++++++++++++++++++-------
 docs/blocks/event/ctrl.js   | 12 ++++++++----
 docs/blocks/event/test.js   |  8 +++++++-
 docs/blocks/event/view.html |  2 +-
 docs/index.jade             |  1 -
 index.html                  | 29 ++++++++++++++++++-----------
 readme.md                   | 17 +++++++++--------
 7 files changed, 66 insertions(+), 33 deletions(-)

diff --git a/checklist-model.js b/checklist-model.js
index 446f910..391d831 100644
--- a/checklist-model.js
+++ b/checklist-model.js
@@ -54,6 +54,7 @@ angular.module('checklist-model', [])
     var getter = $parse(checklistModel);
     var setter = getter.assign;
     var checklistChange = $parse(attrs.checklistChange);
+    var checklistBeforeChange = $parse(attrs.checklistBeforeChange);
 
     // value added to list
     var value = attrs.checklistValue ? $parse(attrs.checklistValue)(scope.$parent) : attrs.value;
@@ -78,23 +79,38 @@ angular.module('checklist-model', [])
       if (newValue === oldValue) { 
         return;
       } 
+
+      if (checklistBeforeChange && (checklistBeforeChange(scope) === false)) {
+        scope[attrs.ngModel] = contains(getter(scope.$parent), value, comparator);
+        return;
+      }
+
+      setValueInChecklistModel(value, newValue);
+
+      if (checklistChange) {
+        checklistChange(scope);
+      }
+    });
+
+    function setValueInChecklistModel(value, checked) {
       var current = getter(scope.$parent);
       if (angular.isFunction(setter)) {
-        if (newValue === true) {
+        if (checked === true) {
           setter(scope.$parent, add(current, value, comparator));
         } else {
           setter(scope.$parent, remove(current, value, comparator));
         }
       }
+      
+    }
 
-      if (checklistChange) {
-        checklistChange(scope);
-      }
-    });
-    
     // declare one function to be used for both $watch functions
     function setChecked(newArr, oldArr) {
-        scope[attrs.ngModel] = contains(newArr, value, comparator);
+      if (checklistBeforeChange && (checklistBeforeChange(scope) === false)) {
+        setValueInChecklistModel(value, scope[attrs.ngModel]);
+        return;
+      }
+      scope[attrs.ngModel] = contains(newArr, value, comparator);
     }
 
     // watch original model change
diff --git a/docs/blocks/event/ctrl.js b/docs/blocks/event/ctrl.js
index 70be993..3333787 100644
--- a/docs/blocks/event/ctrl.js
+++ b/docs/blocks/event/ctrl.js
@@ -6,10 +6,14 @@ app.controller('Ctrl5', function($scope) {
     u: 'User'
   };
 
-    $scope.testValue = 'Im not changed yet!';
-    $scope.imChanged = function(){
-        $scope.testValue = $scope.user.roles.join(',');
-    }
+  $scope.testValue = 'Im not changed yet!';
+  $scope.imChanged = function(){
+    $scope.testValue = $scope.user.roles.join(',');
+  }
+  $scope.shouldChange = function(key){
+console.log("should change " + key);
+    return key !== "g";
+  }
 
   $scope.user = {
     roles: ['c']
diff --git a/docs/blocks/event/test.js b/docs/blocks/event/test.js
index d594cfa..09f8fca 100644
--- a/docs/blocks/event/test.js
+++ b/docs/blocks/event/test.js
@@ -10,7 +10,13 @@ describe('event', function() {
   it('should check of roles are changed to new value before checklist-change is fired', function() {
     element(s+'button[ng-click="checkFirst()"]').click();
     check(a, [1,0,0,0]);
-    expect(element(s+'pre').text()).toBe('"a"');
+    expect(element(s+'pre').text()).toEqual("\"a\"");
+  });
+
+  it('should check that checklist-before-change can deny change of values', function() {
+    element(s+'button[ng-click="checkAll()"]').click();
+    check(a, [1,1,0,1]);
+    expect(element(s+'pre').text()).toEqual("\"a,c,u\"");
   });
 
 });
\ No newline at end of file
diff --git a/docs/blocks/event/view.html b/docs/blocks/event/view.html
index fdc86a1..4ad4bb3 100644
--- a/docs/blocks/event/view.html
+++ b/docs/blocks/event/view.html
@@ -1,3 +1,3 @@
 <label ng-repeat="(key, text) in roles">
-  <input type="checkbox" checklist-change="imChanged()" checklist-model="user.roles" checklist-value="key"> {{text}}
+  <input type="checkbox" checklist-before-change="shouldChange(key)" checklist-change="imChanged()" checklist-model="user.roles" checklist-value="key"> {{text}}
 </label>
\ No newline at end of file
diff --git a/docs/index.jade b/docs/index.jade
index 6573f57..f8b28e8 100644
--- a/docs/index.jade
+++ b/docs/index.jade
@@ -6,7 +6,6 @@ html(ng-app='app')
     title Checklist-model - AngularJS directive for list of checkboxes
 
     // Bootstrap 3
-    script(src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js")
     link(href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css", rel="stylesheet", media="screen")
     link(href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap-theme.min.css", rel="stylesheet", media="screen")
 
diff --git a/index.html b/index.html
index ade9c2f..741d803 100644
--- a/index.html
+++ b/index.html
@@ -5,7 +5,6 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>Checklist-model - AngularJS directive for list of checkboxes</title>
     <!-- Bootstrap 3-->
-    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
     <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css" rel="stylesheet" media="screen">
     <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap-theme.min.css" rel="stylesheet" media="screen">
     <!--docs css-->
@@ -831,7 +830,7 @@ <h2 style="margin-bottom: 0">Event</h2>
         <div class="col-xs-12 col-sm-6">
           <h3>demo</h3>
           <div class="well"><label ng-repeat="(key, text) in roles">
-  <input type="checkbox" checklist-change="imChanged()" checklist-model="user.roles" checklist-value="key"> {{text}}
+  <input type="checkbox" checklist-before-change="shouldChange(key)" checklist-change="imChanged()" checklist-model="user.roles" checklist-value="key"> {{text}}
 </label></div>
           <script>app.controller('Ctrl5', function($scope) {
   $scope.roles = {
@@ -841,10 +840,14 @@ <h3>demo</h3>
     u: 'User'
   };
 
-    $scope.testValue = 'Im not changed yet!';
-    $scope.imChanged = function(){
-        $scope.testValue = $scope.user.roles.join(',');
-    }
+  $scope.testValue = 'Im not changed yet!';
+  $scope.imChanged = function(){
+    $scope.testValue = $scope.user.roles.join(',');
+  }
+  $scope.shouldChange = function(key){
+console.log("should change " + key);
+    return key !== "g";
+  }
 
   $scope.user = {
     roles: ['c']
@@ -881,7 +884,7 @@ <h3>testValue</h3>
         <div class="col-xs-12">
           <h3>html</h3>
           <pre class="prettyprint ng-non-bindable">&lt;label ng-repeat=&quot;(key, text) in roles&quot;&gt;
-  &lt;input type=&quot;checkbox&quot; checklist-change=&quot;imChanged()&quot; checklist-model=&quot;user.roles&quot; checklist-value=&quot;key&quot;&gt; {{text}}
+  &lt;input type=&quot;checkbox&quot; checklist-before-change=&quot;shouldChange(key)&quot; checklist-change=&quot;imChanged()&quot; checklist-model=&quot;user.roles&quot; checklist-value=&quot;key&quot;&gt; {{text}}
 &lt;/label&gt;</pre>
           <h3>js</h3>
           <pre class="prettyprint">var app = angular.module(&quot;app&quot;, [&quot;checklist-model&quot;]);
@@ -893,10 +896,14 @@ <h3>js</h3>
     u: 'User'
   };
 
-    $scope.testValue = 'Im not changed yet!';
-    $scope.imChanged = function(){
-        $scope.testValue = $scope.user.roles.join(',');
-    }
+  $scope.testValue = 'Im not changed yet!';
+  $scope.imChanged = function(){
+    $scope.testValue = $scope.user.roles.join(',');
+  }
+  $scope.shouldChange = function(key){
+console.log(&quot;should change &quot; + key);
+    return key !== &quot;g&quot;;
+  }
 
   $scope.user = {
     roles: ['c']
diff --git a/readme.md b/readme.md
index ca43ff7..74a8365 100644
--- a/readme.md
+++ b/readme.md
@@ -13,14 +13,15 @@ from several checkboxes.
 ## Usage
 You should play with attributes of `<input>` tag:
   
-| Attribute          | Mandatory | Description                                   |
-| :----------------: | :-------: | --------------------------------------------- |
-| `checklist-model`  | Yes       | Use instead of `ng-model`                     |
-| `checklist-value`  | No        | What should be picked as array item           |
-| `value`            | No        | What should be picked as item, but unlike `checklist-value`, this does not evaluate as an angular expression, but rather a static value |
-| `ng-model`         | No        | Every checkbok will span a new scope and define a variable named `checked` to hold its state. You can modify this name by using this attribute. |
-| `checklist-comparator` | No   | A custom comparator. If it starts with dot(`.`) then it will be an expression applied to the array item. Otherwise it should evaluate to a function as an angular expression. The function return true if the first two arguments are equal and false otherwise. |
-| `checklist-change` | No       | An angular expression evaluated each time the `checklist-model` has changed. |
+| Attribute                 | Mandatory | Description                                   |
+| :-----------------------: | :-------: | --------------------------------------------- |
+| `checklist-model`         | Yes       | Use instead of `ng-model`                     |
+| `checklist-value`         | No        | What should be picked as array item           |
+| `value`                   | No        | What should be picked as item, but unlike `checklist-value`, this does not evaluate as an angular expression, but rather a static value |
+| `ng-model`                | No        | Every checkbok will span a new scope and define a variable named `checked` to hold its state. You can modify this name by using this attribute. |
+| `checklist-comparator`    | No   | A custom comparator. If it starts with dot(`.`) then it will be an expression applied to the array item. Otherwise it should evaluate to a function as an angular expression. The function return true if the first two arguments are equal and false otherwise. |
+| `checklist-before-change` | No       | An angular expression evaluated each time before the `checklist-model` has changed. If it evaluates to 'false' then the model will not change anymore. |
+| `checklist-change`        | No       | An angular expression evaluated each time the `checklist-model` has changed. |
 
 * If you modify directly the value of the `checklist-model`, it is possible that the UI won't be updated. This is because this directive looks for the model in the parent, not in the current scope. Instead of doing `checklistModelList = []` it is better to do `checklistModelList.splice(0, checklistModelList.length)` or wrap it in another object.
 * If you're using `track by` you must specify the same thing for `checklist-value` too. See [#46](https://github.com/vitalets/checklist-model/issues/46).