I'm using Angular Material's autocomplete, and I'd like to use the old value when the item changes.
The autocomplete directive is dynamically added to the web page, so using the $watch threads isn't really ideal for this case when there's potential for numerous amount of these autocompletes.
You can use a $watch on the variable like this:
$scope.$watch('variable_name', function(newval, oldval) {
console.log(newval) //contains new value
console.log(oldval) //contains old value
})
So, whenever your item changes this watch block will be triggered and you can access the old and new values.
Related
I have a complicated setup. My application is driven by a set of "rules" which dictate what the user interface is. The UI is rendered by looping through the rules and creating the individual dropdowns. Initially, everything renders properly. However, once a user makes a change to the UI, other rules may be affected. In my application, an api call is made, which then returns a modified set of rules. In the attached plunker, I've simplified things such that only the new set of rules is applied, which causes the page to re-render. The problem is that my users would like to be able to tab between all of the entries on the page and make changes. However, once the page is re-rendered, the currently selected page element is now gone nothing has the focus. I've tried to put the focus back on the proper element by tracking a common Id, but to no avail.
Using either of these doesn't seem to work.
var el = document.getElementById(focusId);
el.focus();
angular.element(el).focus();
I've also tried using the autofocus attribute on the dropdown that I want to have focus, but that didn't work either. I'm using angularjs 1.2. Any ideas are appreciated.
http://plnkr.co/edit/ND9PKqULIOlixWR4XChN?p=preview
If you want to assign auto focus dynamically to a element on the DOM from angular you can use this:
var myEl = angular.element(document.querySelector('select'));
myEl.attr('autofocus',"attr val");
You can also pass in an id like: angular.element(document.querySelector('#focusId'));
You can look here for a prior answer which may be of some more help!
-Cheers!
Problem here is, you are trying to focus the element before the blur event completes. So you need to execute the focus code after blur event. Async execution of your focus code would solve the problem. You can use either setTimeout or $timeout.
setTimeout(function(){
angular.element('#'+focusId).focus();
/* //or
var el = document.getElementById(focusId);
el.focus();
*/
});
or
$timeout(function(){
angular.element('#'+focusId).focus();
/* //or
var el = document.getElementById(focusId);
el.focus();
*/
});
dont forgot to inject $timeout to your controller if you are using second code. Hope this helps :)
Using django-automcomplete-light V3 and angular on a non admin page.
Using the widget autocomplete.ModelSelect2
Where is the selected value stored? Using firebug, it's not in a new hidden html element and if i attempt to watch the original (now hidden) select element, it's value never changes if I change the selected value in the autocomplete widget.
How can angular watch/read this value?
Update:
As #visegan below points out you can use jquery syntax to get the value but for some reason you can't watch it.
i.e. this watch never gets triggered:
$scope.$watch(function(){
return $('#id_field').val();
},
function(newVal, oldVal){
console.log('current %r', newVal);
$scope.models.foo=parseInt(newVal);
});
Well I have just tried with my project and it was pretty straight forward:
$('#id_field').val()
To be honest, I am also not sure where exactly does the value come from.
As for the change watcher: autocomplete light now uses select2 component, which is apparently a bit problematic with angular.
There are two approaches that works: first one is to add more jquery:
$('#id_field').change(function() {alert('changed')});
This I have tested. The other approach is to do it somehow natively. Look at Select2 event handling with Angular js
I'm able to find form data is changed or not using $dirty.
ex: I changed text box or drop down and then $dirty become true. If I reverted to old data still it is true. I need to know if my changes are reverted or not. Do we have any property in Angularjs? If property is true I want to enable save button otherwise it should be disable.
https://docs.angularjs.org/api/ng/type/form.FormController
I need to implement around 10 pages and each page has 10 text boxes and a couple of drop downs. So I don't want track each control manually in my pages.
You can try using this module: https://github.com/betsol/angular-input-modified
From the README file:
This Angular.js module adds additional properties and methods to the
ngModel and ngForm controllers, as well as CSS classes to the
underlying form elements to provide end-user with facilities to detect
and indicate changes in form data.
This extra functionality allows you to provide better usability with
forms. For example, you can add decorations to the form elements that
are actually changed. That way, user will see what values has changed
since last edit.
Also, you can reset an entire form or just a single field to it's
initial state (cancel all user edits) with just a single call to the
reset() method or lock new values (preserve new state) just by calling
overloaded $setPristine() method.
DISCLAIMER: I haven't tried it myself and I notice the author overwrites the ngModel directive instead of adding a decorator, which could be dangerous...but at the very least, you can look at the source and get an idea of how to write your own service or directive with similar functionality.
Even though it does not follow the usage of $dirty, but an implementation similar to this might be helpful for you in the case of a Save button on update.
Inside your html:
<form name="testForm" ng-controller="ExampleController" ng-submit=" save()">
<input ng-model="val" ng-change="change()"/>
<button ng-disabled="disableSave">Save</button>
</form>
Inside your controller:
.controller('ExampleController', ['$scope', function($scope) {
$scope.disableSave = true; // Keep save button disabled initially
$scope.val = 'Initial'; // Initial value of the variable
var copyVal = $scope.val; // Copy Initial value into a temp variable
$scope.change = function() {
$scope.disableSave = $scope.val === copyVal;
};
$scope.save = function() {
// Save the updated value (inside $scope.val)
console.log($scope.val);
// Re-disable the input box (on successful updation)
copyVal = $scope.val;
$scope.disableSave = true;
};
}]);
Here is a working plunkr for the same.
after some research and study of examples I implemented a pagniation with a filter function.
Im very new to angular, so I need your help if this application is ok or it has some bugs/logical errors.
The target is to select a collection (in this application load1 or load2) and create new objects, manipulate existing, or delete some of them. On every update of the data, it has to be checked if the pagination is synchronous to the collection size.
If the user enters something into the search field, a watcher in the controller is fired for updating the filtered data:
$scope.$watch('search.name', function (newVal, oldVal) {
$scope.filtered = filterFilter($scope.items, {name: newVal});
}, true);
I would be very happy if some of you angular pros can look into this code and give me some feedback. I want to use this in a productive system, so every answer would be great!
Here is a working plunkr: http://plnkr.co/edit/j9DVahEm7y1j5MfsRk1F?p=preview
Thank you!
Watchers are heavy if you use them explicitly throughout your large application.
Use ng-change instead. Also, by passing true to that watcher means you're deep watching which is really a bad thing to do, since it will check each property of the object in the array which is performance intensive.
Since I can't see that you need old and new value for a reason, you can simply use $scope.search.name. Whenever you type in something, $scope.search.name has the updated value. Just need to call a function on ng-change.
DEMO: http://plnkr.co/edit/TWjEoM3oPdfrHfcru7LH?p=preview
Remove watch and use:
$scope.updateSearch = function () {
$scope.filtered = filterFilter($scope.items, {name: $scope.search.name});
};
In HTML:
<label>Search:</label> <input type="text" ng-model="search.name" placeholder="Search" ng-change="updateSearch()" />
Previous answer is still the correct, but you will have to make sure to replace the "page" inside the pagination tag and change it to ng-model.
From the changelog (https://github.com/angular-ui/bootstrap/blob/master/CHANGELOG.md)
Since 0.11.0:
Both pagination and pager are now integrated with ngModelController.
page is replaced from ng-model.
Assuming a given form such as <form name="myForm">, it's easy enough to watch for validity, error, dirty state, etc. using a simple watch:
$scope.$watch('myForm.$valid', function() {
console.log('form is valid? ', $scope.myForm.$valid);
});
However, there doesn't appear to be an easy way to watch if any given input in this form has changed. Deep watching like so, does not work:
$scope.$watch('myForm', function() {
console.log('an input has changed'); //this will never fire
}, true);
$watchCollection only goes one level deep, which means I would have to create a new watch for every input. Not ideal.
What is an elegant way to watch a form for changes on any input without having to resort to multiple watches, or placing ng-change on each input?
Concerning the possible duplicate and your comment:
The directive solution in that question works, but it's not what I had in mind (i.e. not elegant, since it requires blur in order to work).
It works if you add true as third parameter for your $watch:
$scope.$watch('myFormdata', function() {
console.log('form model has been changed');
}, true);
Further information see the docs.
Working Fiddle (check console log)
Another more angular way would be to use angular's $pristine. This boolean property will be set to false once you manipulate the form model:
Fiddle
Based on my experience with my forms (new dev, but working with Angular for a while now), the elegant way to watch a form for changes is actually not to use any type of watch statement at all actually.
Use the built-in Angular boolean $pristine or $dirty and those values will change automatically on any input field or checkbox.
The catch is: it will not change the value if you add or splice from an array which had me stumped for a while.
The best fix for me was to manually do $scope.MyForm.$setDirty(); whenever I was adding or removing from my different arrays.
Worked like a charm!