I have used angular's ng-model for quite some time which demonstrates two way data binding. What i want to accomplish is to bind only an input field to a model only if there are changes.
If I have
<input value="Hello world">
I want the value to be propagated to a model variable only if there are changes made to the value.
Answer would depend on event you want to use to update model.
Assuming you are wanting an "edit form " but don't want the master model to update live you can make a copy of the model and extend the master on "save"
Starting data:
$scope.item ={age: 25, name: 'Foo Bar'};
$scope.editItem = angular.copy($scope.item);
HTML
<input ng-model="editItem.age">
<button ng-click="updateItem()">Update</button>
Update function:
$scope.updateItem = function (){
$http.put(url, $scope.editItem).success(function(resp){
// merge data
angular.extend( $scope.item, $scope.editItem);
});
}
You could also do something similar using ng-change
You can do it with using of additional variable and $watch. Example:
<input type="search" ng-model="searchText">
And in controller
$scope.$watch('searchText', function() {
$scope.filterText = $scope.searchText;
});
So $scope.filterText will be changed to $scope.searchText value if any changes in input
Related
I need to automatically populate second textbox once the first textbox is populated by user using angularjs. Both of them have their own ng-model so I can not change ng-model. Is there a way I can just copy the value from first textbox to second by keeping ng-model different?
In the controller, you need to build the logic to assign model1 value to model2 whenever there is a change in model1
Your html part :
<input ng-model='model1" ng-change="update2()">
<input ng-model='model2" >
And somewhere in the relevant controller,
$scope.update2 = function(){
$scope.model2 = $scope.model1;
}
You can monitor changes to your $scope using the $watch function. This is a more appropriate way for binding changes in Angular. try below snippet:
Controller:
$scope.$watch('first',function(){
$scope.second = $scope.first;
});
HTML:
<input ng-model='first'>
<input ng-model='second' >
End goal: Associate multiple email addresses, each with a frequency setting (daily,weekly,monthly), to a notification.
I am attempting to define a directive which acts on a button element, such that, when the button is clicked, it takes the email address from the input element and the frequency from the drop-down next to the button and inserts them into a list below the input+button and binds the dynamic list to a property on the controller so it can be sent to the server when the user submits the form.
The form is all wired up - thats not the question.
I just want some help in building the directive.
Here's what i have so far:
HTML:
<section ng-controller="notificationmanagement as vm">
<input name="email" type="email"/>
<select>
<option>Daily</option>
<option>Monthly</option>
<option>Weekly</option>
</select>
<button data-cm-click type="button" class="btn btn-default"></button>
<div ng-model="vm.Subscribers"></div>
</section>
Directive:
commonModule.directive('cmClick', function () {
return function (scope, element) {
element.bind("click", function () {
// Is this the best way to get the value of the EmailAddress & Frequency?
var emailAddress = element[0].parentElement.parentElement.children[0].value;
var frequency = element[0].parentElement.parentElement.children[1].value;
var spanEmailTag = angular.element('<span>' + emailAddress + '</span>');
var spanFreqTag = angular.element('<span>' + frequency + '</span>');
angular.element(spanEmailTag).appendTo(element[0].parentElement.parentElement);
angular.element(spanFreqTag).appendTo(element[0].parentElement.parentElement);
// How to make sure each added email+frequency is available
// in the array bound to 'vm.Subscribers'
});
}
});
The structure of 'vm.Subscribers' should be something like this, in order for it be consumed by the server:
vm.Subscribers = [ {'EmailAddress':'joe#email.com', 'Frequency':'Daily'}, {'EmailAddress':'bob#email.com', 'Frequency':'Monthly'} ];
NOTE: I would ideally like to achieve this without relying on jQuery within the directive.
Any and all pointers/help/advice would be most appreciated!
If you want to encapsulate and reuse some functionality, then, by all means, use a directive.
But first, understand the MVVM (Model-View-ViewModel) paradigm and how Angular implements this.
For starters, assume that there is no View (and so, no DOM, directives, etc...) and that user inputs magically occur when something is exposed on the $scope (or, if you are using ControllerAs - as a property of the controller). Now, build you app's functionality starting from the controller. Define the data structure and the behavior with functions.
app.controller("notificationmanagement", function(){
// list of subscribers. You could also populate it from the backend.
this.subscribers = [];
// this is where the details of a new subscriber will be stored
// until subscriber is added
this.newSubscriber = {EmailAddress: null, Frequency: null};
// action to add a susbscriber
this.addSubscriber = function(){
this.subscribers.push(this.newSubscriber);
// clear the object (it's not necessary to declare all the properties)
this.newSubscriber = {};
}
});
That is, in a nutshell, all your app is doing. The controller doesn't (and shouldn't) care how this is displayed in the View. This is why DOM manipulation is frown upon, because it breaks separation of concerns.
Now, to the View. The View is mostly declarative:
<section ng-controller="notificationmanagement as vm">
<input ng-model="vm.newSubscriber.EmailAddress" type="email>
<select ng-model="vm.newSubscriber.Frequency">
<option value="Daily">Daily</option>
<option value="Monthly">Monthly</option>
<option value="Weekly">Weekly</option>
</select>
<button ng-click="vm.addSubscriber()"> Add </button>
<hr/>
<h3>All subscribers:</h3>
<div ng-repeat="s in vm.subscribers">
<span>{{s.EmailAddress}}</span>
<span>{{s.Frequency}}</span>
</div>
</section>
Notice how ng-model directives bind input data to controller's data. Notice ng-click that invokes an action on the controller. Notice ng-repeat that iterates and creates DOM elements based on that data. The View is purely driven by data, which is referred to by ViewModel.
Understand this first, then move onto directives.
I have used ng-paste for textarea while pasting the link in textarea, i am calling a custom function to store that value. Please refer following code
<textarea rows="1" ng-model="myObj.content"
ng-paste="getContent(myObj)">
</textarea>
$scope.getContent = function(a){
console.log(a.content);
}
But in console always I am getting undefined value. How can I get my object value?
Passing model to function does not really make sense since you have already specified ng-model, so it's value will be updated as user types something into the textbox. If you want to track changes you can setup a $watch for your model or specify a function using ng-change.
If you want to know what user pasted, then that's another story. Handling ng-paste can be tricky. To access the actual event, easiest is to include jQuery before angularjs and then do e.g. following:
HTML template
<textarea rows="3"
placeholder="copy/paste here..."
ng-init="content = null"
ng-model="content"
ng-paste="paste($event.originalEvent)">
</textarea>
Controller
$scope.paste = function (event) {
var item = event.clipboardData.items[0];
item.getAsString(function (data) {
console.log(data);
});
};
Related plunker here http://plnkr.co/edit/ea5y5j
Simply use $timeout to call your paste callback after the model has been updated.
$scope.getContent = function(a){
$timeout(function () {console.log(a.content)});
}
i tried calling the values using ng-change between two different ng-models. it works.
but the data is parsed to the other ng-model only if the data is changed, is there any alternate solution where i can have the data in both ng-models before changing data
I tried something like this
HTML
<input ng-model="customer.name" ng-change='tripsheet.customer_name=customer.name;'>
<input ng-model="tripsheet.customer_name" type="text" class="form-control input-lg" placeholder="Customer Name">
JS
$scope.customer = {
name:$scope.customers[$scope.whichItem].name,
address:$scope.customers[$scope.whichItem].address,
phone:$scope.customers[$scope.whichItem].phone
}
i want the routeParams data in both the above ng-models.
With something like this in your controller?
$scope.customer = {
name: "Tom"
};
$scope.tripsheet = {
customer_name: $scope.customer.name
}
Plunker
#mainguy's answer is a very good approach.
Or alternatively you can go with $watch instead of ng-change.
initialize a watcher for the model object
$scope.$watch('customer.name', customerNameChanged);
and define the function
function customerNameChanged() {
if(!$scope.tripsheet)
$scope.tripsheet = {};
$scope.tripsheet.customer_name = $scope.customer.name
}
ng-change triggers only when there is a user interaction and the data is changed.
$watch is triggered when the model object is changed programmatically and also when they’re being defined the first time
I have following controller.
app.controller("testCtrl", function(){
$scope.utcTime = 1380150771;
$scope.parseTime = function(t){
//return local time string
}
});
In the view, I have
<input type="text" ng-model="parseTime(utcTime)" />
Its not working. Can I bind ng-model to a method that returns the string ?
Any alternative way to show the value in the input button ?
You can use ngChange and ngModel both
JS
$scope.utcTime = 1380150771;
$scope.parseTime = function(){
console.log($scope.utcTime);
//return local time string
}
HTML
<input type="text" ng-change="parseTime()" ng-model="utcTime" />
ng-model is mapping through tag and controller.
At first you can see default utcTime (1380150771) that you assign in input tag.
And when you change the text in input tag, ng-model(utcTime) will be changed automatically in the controller.
Then each letter that you typed will call ng-change(parseTime) function.
You can check by console.log method.
My solution is based on this source:
https://groups.google.com/forum/#!topic/angular/1mnra0vamtg
I have edited the Plunker sample code to use ng-value to generate and update ng-model using calculation function. See this link below:
http://plnkr.co/edit/Fmqw0wp37Ndk1yuWvFkV?p=preview
Also, the above sample shows you how you format the result for display using custom filter.
In other posts, some have suggested using $watch() to detect change to input variables and update ng-model variable accordingly. Using ng-value is much better than using $watch() since the latter forces you to include all input variables in the watch which may be impossible if you have very complex calculation model.
Tarek
Try doing this
app.controller("testCtrl", function(){
$scope.utcTime = 1380150771;
$scope.result= $scope.parseTime( $scope.utcTime)
$scope.parseTime = function(t){
//return local time string
}
});
html
<input type="text" ng-model="result" />
Yes you can try follwing:
its working example:
<input type="text" ng-model="parseTime(utcTime)" />
app.controller("testCtrl", function(){
$scope.utcTime = 1380150771;
$scope.parseTime = function(t){
//return local time string
new Date(t).toISOString();
}
});