AngularJS：如何在ng-repeat中使用ng-default设置表单默认值？

Hey there! Quick heads-up first: AngularJS doesn’t have an ng-default directive out of the box. But don’t worry—we’ve got a few straightforward ways to set default values for your inputs when looping with ng-repeat, based on the _text property in your JSON data.

Option 1: Bind to a Model (Two-Way Binding) #

This is the most flexible approach if you need to track changes to the input value.

First, in your controller, extend each item in ValueArr with a model property initialized from its _text value:

// Process your input array to add a model property
$scope.ValueArr = yourJsonValues.map(item => {
  return {
    ...item,
    // Use _text as default if it exists, else empty string
    model: item._text || ''
  };
});

(If you’re dealing with numbers like data.concurrent, convert the value to a number: model: item._text ? Number(item._text) : 0)

Then update your HTML to bind the input to this new model property:

<b style="padding-top:5px;">&nbsp;Comments:</b> 
<span class="input">
  <input class="inputtxt" type="text" 
         ng-repeat="x in ValueArr" 
         ng-if="x._attributes.name === 'data.comments'"
         ng-model="x.model" />
</span>

Now the input will load with the _text value as the default, and any changes the user makes will be stored in x.model.

Option 2: Static Default with value Attribute #

If you don’t need two-way binding (just a static default that doesn’t update the original data), use the value attribute with Angular interpolation:

<b style="padding-top:5px;">&nbsp;Comments:</b> 
<span class="input">
  <input class="inputtxt" type="text" 
         ng-repeat="x in ValueArr" 
         ng-if="x._attributes.name === 'data.comments'"
         value="{{x._text || ''}}" />
</span>

This will set the initial value, but user input won’t affect your original ValueArr items.

Option 3: Initialize Model with ng-init #

If you prefer to keep the initialization in the HTML instead of the controller, use ng-init:

<b style="padding-top:5px;">&nbsp;Comments:</b> 
<span class="input">
  <input class="inputtxt" type="text" 
         ng-repeat="x in ValueArr" 
         ng-if="x._attributes.name === 'data.comments'"
         ng-init="x.model = x._text || ''"
         ng-model="x.model" />
</span>

This does the same as Option 1 but handles the model setup directly in the template.

Quick Tip: #

Make sure your ng-if condition correctly targets the right item—I filled it in to check for data.comments since that’s the input you referenced, but adjust it as needed for other fields!

内容的提问来源于stack exchange，提问作者usersam