ng-model一次更改所有选择

Question

jsfiddle

Hi.
I have a problem with my application. I have to write several selects by using ng-repeat and each of these selects must be filled with the same data.

The problem is, when the one is changed, others selects are changes to the same value - why?.

I suppose that the problem is in the ng-model - maybe I don't understand how the "hierarchy" of the ng-model works.

• If the name of the ng-model is only "option" - it doesn't work!
• If the name of the ng-model is "something.option" - it also doesn't work!
• If the name of the ng-model is "something.else.option" - it does work but all selects are filled!

HTML:

<div ng-controller="MyCtrl">
  <div ng-if="models" ng-repeat="m in models">
    <br><label>{{m.model}} ({{m.no}})</label><br>

    <select ng-model="models.m.opModel" ng-options="opt.value as opt.text for opt in options" ng-change="foo()"></select>
    </div>
 </div>

JS:

var myApp = angular.module('myApp',[]);

function MyCtrl($scope) {
    $scope.models = [
         {'no':'A', 'model':'alpha'},
         {'no':'B', 'model':'beta'},
         {'no':'C', 'model':'gamma'}
         ];
    $scope.options = [
         {'value':1, 'text':'one'},
         {'value':2, 'text':'two'},
         {'value':3, 'text':'three'}
         ];

     $scope.foo = function(){
                alert($scope.models.m.opModel);
     }
}

What am I doing wrong?

Thanks a lot.

Answer 1

You've created a scope object called "m" which is the current child of the "models" list. So for each dropdown, you're going to have a different "m" scope object. This is what you need to bind to in your ng-model so that the dropdown is bound to its unique parent in the "models" list.

Change <select ng-model="models.m.opModel"> to <select ng-model="m.opModel" to fix the problem.

To access the value with the foo() function, you'll need to use this updated function:

 $scope.foo = function(index){
   alert($scope.models[index].opModel)
 }

And update the <select> like this:

<select ng-model="m.opModel" ng-options="opt.value as opt.text for opt in options" ng-change="foo($index)"></select>

You're creating an ng-model called "opModel" in the ng-repeat which means you'll have three new opModels under $scope.models. This is an array you can access later using an index value to specify which of the $scope.models[].opModel you want to access.

Notice that I've changed the ng-change code to send the current $index which is basically an ng-repeat counter. So your foo() function will receive either a 0, 1 or 2 which lets us access the specific ngModel that we need to access.

Answer 2

You are binding to the single object models . Inside an ng-repeat the repeated is available "in scope". You probably want to change this code to:

<div ng-controller="MyCtrl">
  <div ng-if="models" ng-repeat="m in models">
    <br><label>{{m.model}} ({{m.no}})</label><br>

    <select ng-model="m.opModel" ng-options="opt.value as opt.text for opt in options" ng-change="foo()"></select>
    </div>
 </div>

Look at the ng-model="m.opModel" , that is what I've changed. You are now updating the value of the single item, and not inserting a new object into an array which is then reused by all the ng-repeat items (which is why all the values would update at the same time).