Is it not possible (or not yet possible) to use ngModel against values from ngFor? Is Angular trying to protect me from bad performance?
Works great: http://jsfiddle.net/langdonx/n5pjgev6/
<input type="text" [(ng-model)]="value">{{value}}
Does not work so great: http://jsfiddle.net/langdonx/n5pjgev6/1
<li *ng-for="#name of names">
<input type="text" [(ng-model)]="name">{{name}}
</li>
EXCEPTION: Cannot reassign a variable binding name
I tried binding to the array as well, which... kind of works, but hijacks focus and also throws an exception: http://jsfiddle.net/langdonx/n5pjgev6/2/
<li *ng-for="#name of names; #i = index">
<input type="text" [(ng-model)]="names[i]">{{name}}
</li>
EXCEPTION: LifeCycle.tick is called recursively
Edit:
I can get around the LifeCycle.tick issue using a more direct approach, but the focus is still stolen because ngFor redraws things: http://jsfiddle.net/langdonx/n5pjgev6/3/
<li *ng-for="#name of names; #i = index">
<input type="text" [value]="names[i]" (input)="names[i] = $event.target.value">{{names[i]}}
</li>
I think ngFor don't like tracking array elements which are primitive values having ngModel on them.
If you remove the ngModel inside the loop, it works.
It works too when I update jsfiddle with :
this.names = [{name: 'John'}, {name: 'Joe'}, {name: 'Jeff'}, {name: 'Jorge'}];
and
<li *ng-for="#n of names"><input type="text" [(ng-model)]="n.name">{{n.name}}</li>
A solution is to reference the value inside ngModel by its index. Therefore [(ngModel)]="names[index]".
But this is not sufficient because *ngFor tracks items by value. As soon as the value is changed the old value cannot be tracked. So we need to change the tracking function to return an index, thus trackBy: trackByIndex.
This issue is explained here.
Solution:
#Component({
selector: 'my-app',
template: `
<div>
<input type="text"
*ngFor="let name of names; let nameIndex = index; trackBy: trackByIndex"
[(ngModel)]="names[nameIndex]"/>
<br/>
{{ names | json }}
</div>
`,
})
export class App {
names: string[];
constructor() {
this.names = ['a', 'b', 'c'];
}
public trackByIndex(index: number, item) {
return index;
}
}
Related
how to watch the array value of ng-model in angularjs i have created fiddle but does not work Please take a look and suggest.
Thanks
<div ng-app ng-controller="ParentCtrl">
<div ng-controller="ChildCtrl">
<table>
<tr ng-repeat="user in profiles track by $index">
<td>
<input
type="text"
name="parktime_{{user.user_id}}"
ng-model="orderItems[user.user_id].parktime"
>
</td>
</tr>
</table>
</div>
</div>
function ParentCtrl($scope) {
}
function ChildCtrl($scope) {
$scope.parkOptions = {};
$scope.profiles = [
{user_id: '01', park_name: 'England Park'},
{user_id: '02', park_name: 'France Park'}
];
$scope.orderItems = {};
$scope.orderItems.parktime = "Test";
$scope.$watch('orderItems[profiles.user_id].parktime', function(newVal, oldVal){
console.log(newVal);
})
}
http://jsfiddle.net/w5vskLfc/59/
I suggest you use ng-change instead. You can't use watch this way, it is to watch a single property instead.
I've also updated your model to use ng-init. This is something you should be careful with using, but in your case, you need to have an key defined at each position of your orderItems object. If you will always statically assign these, I recommend iterating through them once and creating a key that way instead.
HTML
<input type="text" name="parktime_{{user.user_id}}"
ng-init="orderItems[user.user_id] = {}"
ng-model="orderItems[user.user_id].parktime"
ng-change="onChange(user.user_id)">
JS
$scope.onChange = function(items) {
console.log(items);
}
You are trying to access indexes which does not exist. profiles is an array of objects and I don't think there is anything available on profiles.user_id index. Also, I don't think orderItems[profiles.user_id] will work as that index also doesn't exist.
I have a simple input that I want to reset the value to empty string after I am adding hero. The problem is the value is not updated. why?
#Component({
selector: 'my-app',
template: `
<input type="text" [value]="name" #heroname />
<button (click)="addHero(heroname.value)">Add Hero!</button>
<ul>
<li *ngFor="let hero of heroes">
{{ hero.name }}
</li>
</ul>
`,
})
export class App {
name: string = '';
heroes = [];
addHero(name: string) {
this.heroes.push({name});
// After this code runs I expected the input to be empty
this.name = '';
}
}
You have one-way binding so when you're typing something in your input your name property isn't changed. It remains "". After clicking on Add hero! button you doesn't change it.
addHero(name: string) {
this.heroes.push({name}); // this.name at this line equals ''
this.name = ''; // it doesn't do any effect
}
Angular2 will update value property only if it is changed.
Use two-way binding which is provided by #angular/forms
[(ngModel)]="name"
to ensure that your name property will be changed after typing.
Another way is manually implementing changing
[value]="name" (change)="name = $event.target.value"
In Angular Template binding works with properties and events, not attributes. as per html attribute vs dom property documentation of angular so as you have used [value] binding its binding to attributes not to the property of that input and because of it value remain in it after you set this.name = "".
So I have some code that looks like this:
<input ng-model="search" type="text">
<td ng-repeat="key in targets">
{{ display_names[key] }}
</td>
To be more clear:
targets is a variable containing not-human readable ids such as key012
display_names is an object which has keys like: key012: "USA"
I would like to filter the display_names value from the search? Looking at the angularjs docs, I know I can filter key, but I haven't figured out how to filter display_names
Example
Here's a full example:
var TS = angular.module('myapp', []);
TS.controller('test', function($scope) {
$scope.targets = ["id_1", "id_2"];
$scope.display_names = {
"id_1": "USA",
"id_2": "Mexico"
};
});
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<body ng-app="myapp" ng-controller="test">
<input ng-model="search" placeholder="Search...">
<ul>
<li ng-repeat="key in targets">{{display_names[key]}}</li>
</ul>
</body>
<td ng-repeat="key in targets">
<span ng-if="display_names[key].indexOf(search) > -1">{{ display_names[key] }}</span>
</td>
use ng-if, or you could also use ng-show. Differences here
This way, as you write in search (which should be in $scope.search) angular will refresh the ng-repeat values to show
If you want to search it case-insensitive, you could use toLowerCase() function before using indexOf
display_names[key].toLowerCase().indexOf(search) > -1
You can't use a filter | in the html because you don't have the value you want to filter against in the array you are iterating over. Instead you can use ng-if to show/hide the elements based on the search. Something like:
<div ng-repeat="key in targets" ng-if="!search || !!display_names[key].match(search)">
{{ display_names[key] }}
</div>
The !! boolean cast is done because otherwise a new Regex object will be returned for the match which triggers a digest cycle which will return another new object and so on.
You also probably want to iterate over <tr> rather than <td>, and you need a <table> element for these elements to be allowed.
Example: http://plnkr.co/edit/qrpLKD9x4IBXowpIgnrf?p=preview
You could also write a custom filter for this, but it is a lot more work:
.filter('displayNames' function () {
return function (key, names, search) {
return !search || !!names[key].match(search);
};
});
And use it like key in targets | displayNames:display_names:search
I have an object called user:
It has properties like user.name, user.age e.tc.
Now, I need to add an array to user object called subjects via ng-model.
This is what i did inside of ng-repeat:
<input type="text" ng-model="user.subjectname[$index]"
name="subject" ng-required="true" placeholder="Enter a subject name">
and when I do console.log(user.subjectname), it looks like this:
Now, after this, I wanted to do something like this:
<div ng-repeat="data in user.sujects">
<td>{{data}} </td>
</div>
But it does not work.
Try2:
In my my service that is called from controller, I tried this,
if(dataArray== null)
var dataArray=[];
console.log("scop.user.subjectname...................." + user.subjectname);
for(var i in user.subjectname)
{ dataArray.push(user.subjectname[i])
}
user.data=dataArray;
so, now if I do,
<div ng-repeat="data in user.data">
<td>{{data}} </td>
</div>
I still get nothing.
Can I get some direction to deal with this?
Like I told you in your previous question, and showcased in a jsbin.
You need to use the (key, val) in object syntax to get those values out of user.subjectname
ng-repeat="(key, val) in user.subjectname" ng-bind="val"
If you need to transform this object into an array:
$scope.arr = [];
Object.keys(user.subjectname).forEach(function (key) {
arr.push(user.subjectname[key]);
});
Then if you need to output that
ng-repeat="a in arr" ng-bind="a"
edit: after further explanation from you, I'm assuming this jsBin highlights something close to what you are after.
I'm building an app where users can add items to a list and I decided, for the sake of learning, to use Angular (which I'm very new to). So far, I've been able to successfully add a single item to that list without any issues. Unfortunately, whenever I try to add more than one without a page refresh, I get an error - specifically a "Undefined is not a function."
I've spent more time than I care to think about trying to resolve this issue and I'm hoping an expert out there can give me a hand. Here's what I have so far:
Controllers:
angular.module('streakApp')
.controller('StreakController', function($scope) {
// Removed REST code since it isn't relevant
$scope.streaks = Streak.query();
// Get user info and use it for making new streaks
var userInfo = User.query(function() {
var user = userInfo[0];
var userName = user.username;
$scope.newStreak = new Streak({
'user': userName
});
});
})
.controller('FormController', function($scope) {
// Works for single items, not for multiple items
$scope.addStreak = function(activity) {
$scope.streaks.push(activity);
$scope.newStreak = {};
};
});
View:
<div class="streaks" ng-controller="FormController as formCtrl">
<form name="streakForm" novalidate >
<fieldset>
<legend>Add an activity</legend>
<input ng-model="newStreak.activity" placeholder="Activity" required />
<input ng-model="newStreak.start" placeholder="Start" type="date" required />
<input ng-model="newStreak.current_streak" placeholder="Current streak" type="number" min="0" required />
<input ng-model="newStreak.notes" placeholder="Notes" />
<button type="submit" ng-click="addStreak(newStreak)">Add</button>
</fieldset>
</form>
<h4>Current streaks: {{ streaks.length }}</h4>
<div ng-show="newStreak.activity">
<hr>
<h3>{{ newStreak.activity }}</h3>
<h4>Current streak: {{ newStreak.current_streak }}</h4>
<p>Start: {{ newStreak.start | date }}</p>
<p>Notes: {{ newStreak.notes }}</p>
<hr>
</div>
<div ng-repeat="user_streak in streaks">
<!-- Removed most of this for simplicity -->
<h3>{{ user_streak.fields }}</h3>
</div>
</div>
Could you post the html of StreakController too? Your solution works fine in this fiddle:
http://jsfiddle.net/zf9y0yyg/1/
.controller('FormController', function($scope) {
$scope.streaks = [];
// Works for single items, not for multiple items
$scope.addStreak = function(activity) {
$scope.streaks.push(activity);
$scope.newStreak = {};
};
});
The $scope inject in each controller is different, so you have to define the "streaks" in FormController.
Your problems comes from :
.controller('FormController', function($scope) {
// Works for single items, not for multiple items
$scope.addStreak = function(activity) {
$scope.streaks.push(activity);
^^^^^^
// Streaks is initialized in another controller (StreakController)
// therefore, depending of when is instantiated StreakController,
// you can have an error or not
$scope.newStreak = {};
};
});
A better design would be to implement a StreakService, and to inject that service in the controller you need it. Of course, initializing $scope.streaks in FormController will make your code work, but that's not the responsibility of FormController to initialize this data.
I assume FormController is a nested controller of StreakController, so they share the same scope.
if that works for single object, it should work for mulitiple objects, the problems is you can't just use push to push an array of object to the streaks, you can for loop the array and add them individually or use push.apply trick. I thought the reason of Undefined is not a function. is because the Stack.query() return an element instead of an array of elements so, the method push doesn't exists on the $scope.streaks.
http://jsbin.com/jezomutizo/2/edit