AngularJS: Force ng-repeat update when property of an element changes - angularjs

I'm wrestling with the way angular watches arrays. I have the following markup:
<map name="theMap" center="{{mapInfo.center.toUrlValue()}}" zoom="{{mapInfo.zoom}}" on-dragend="dragEnd()" on-zoom_changed="zoomChanged()">
<marker ng-repeat="pin in pins() track by pin.iconKey()" position="{{pin.latitude}}, {{pin.longitude}}" title="{{pin.streetAddress}}" pinindex="{{$index}}" on-click="click()"
icon="{{pin.icon()}}"></marker>
</map>
Each individual pin returned by pins() has a number of properties, sub-properties, etc. One of those sub-properties controls the marker color. When that subproperty changes I want the UI to update.
Because ng-repeat appears to $watch based on simply changes to the collection it's not obvious how to achieve that. I thought that my tracking function, iconKey(), would do it because it returns a different value depending upon the subproperty's value. But that didn't work.
One other thing: the subproperty gets changed in the callback from an $interval that runs under a directive. I mention this because, in an earlier post, someone thought that there might be a context/scope problem.
However, even when I make the change in an event listener within the UI's controller (where the event is raised within the "success" clause of the $interval callback) it still doesn't work.
That's why I think the problem is just angular not noticing the change in iconKey(); it's acting like all it $watches for ng-repeat is the array's length. Which doesn't change when the subproperty changes.
Update
I've created a plunker to demonstrate the issue I'm facing. You can find it at http://plnkr.co/edit/50idft4qaxqw1CduYkOd
It's a cut down version of the app I'm building, but it contains the essential elements (e.g., a data context service to hold information about the map pins and an $interval service to toggle the subproperty of one of the pin array elements).
You start the update cycle by clicking Start in the menu bar (you may want to drag the map down slightly to put both pins into full view). It should toggle the color of each pin, alternatively, 5 times each, once every 2 seconds. It does this by toggling the value of the isDirty property of the pin object in a listener defined in the controller. The event is raised by the $interval service.
If you break on line 22 during the test cycle you'll see the pin's icon being returned. So something within angular is calling for the information...but the pin color doesn't change.
I look forward to someone quickly pointing out the bone-headed mistake that has nothing to do with any of my theories :). Apologies in advance for whatever blinders I'm wearing.
Update 2
After checking out the code snippet in the response I simplified my plnkr and demonstrated that angular is, in fact, updating the UI when a subproperty changes. So this appears to be a limitation or bug in ng-map.

What you are missing here is the concept of array and function your function pins() passes an array and that array is been bound with ng-repeat. But the brutal fact here is that no matter what that array is never changed, because you do not have ANY reference to that array hence the rg-repeat will always remain as is...
I'll suggest to try get the array be referenced two ways to do that
ng-init="pinsArray = pins()"
and second inside controller
$scope.pinsArray = $scope.pins()
then make changes to $scope.pinsArray inside controller
ng-repeat will be changed to
ng-repeat="pin in pinsArray"
also read about filters I am guessing that's what you where trying to do with "track by"
hope this helps..
Edit: different story with ngMap markers
seems like it doesn't watch sub-property.
so here's a work around
add following statement to you update the pinsArray after making changes to its properties.
pinsArray = angular.copy(pinsArray);
the solved plnkr example:
http://plnkr.co/edit/EnW1RjE9v47nDpynAZLK?p=preview

Related

How do I return focus to an element when the entire page changes?

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 :)

"$watch"ing a service doesn't appear to update reliably

I am currently building a simple drag & drop directive so that I can move some SVG stuff around on the screen. At the moment I'm still in the early stages, but I have run into a strange issue with $watch that I'm hoping someone can help me with.
I have a service that maintains my mouse state. At the moment it's just the x and y coordinates of the cursor. I also have an attribute level directive that interacts with this service in order to bind to the mouse-move event and update the service whenever someone moves the mouse around. These two items work together like a champ. The directive keeps the service up to date with the mouse's position and since my service (Factory really) is a singleton, I can pull this data in to other directives/controllers to see what's going on with the mouse.
Here's the problem: I'm trying to allow a specific SVG element to be dragged around, so I created a super simple controller with two functions: a "trackDrag" function that begins tracking and moving a specific element, and a "releaseDrag" which stops tracking/moving the element (drops it where it is, basically).
Inside of my trackDrag function, I attempt to use $scope.$watch to watch the mouse service's current x and y coordinates. Since it's a factory, these values are returned in a function and my watch looks something like this:
$scope.$watch("mouseTrackingService.get()", function(){
// do some stuff here
});
This watch DOES fire off when I first start dragging an element but it doesn't fire as I continue dragging it across the screen. In my "releaseDrag" function, I deallocate the watcher and that seems to work correctly. I'm kind of stumped about why I don't see the watch fire off continuously, even though I can console write out inside of the service and I see that IT is updating correctly.
I've included a plnkr with some sample code below:
http://plnkr.co/edit/g3WEgiQWvd9oXCpFEByn?p=preview
If I just give in and use a $interval then this code works (updating the position every 10ms for example), but really I see that as a much less "angular" way of doing things vs binding.
Ugh, I'm just being dumb. I forgot that $scope.$watch can ONLY WATCH SCOPE VARIABLES.
I fixed this issue by adding the following wrapper around the service:
$scope.currentMouse = function(){
return mouseTrackingService.get();
};
I can then watch currentMouse:
$scope.$watch(currentMouse(), function(){
updateMousePosition(target);
console.log("noticed a change");
});
Of course that gives me that awful Digest error after more than like a half second of dragging:
Uncaught Error: [$rootScope:infdig] 10 $digest() iterations reached. Aborting!
But that's a different issue entirely.
Sorry folks, nothing to see here. Move along now :-p

Using Angular-Bacons $scope.$watchAsProperty(property) in Angulars ng-repeat

I´m trying to find a good way to use Baconjs together with Angularjs in conjuctions with Angular-Bacon.
Now digesting from Bacon to the Angular scope works perfectly fine but I´m stumbling with Angular-Bacons $scope.$watchAsProperty(property) within Angulars ng-repeat:
Let´s say I have the Angular scope $scope.databaserecords and render it out with:
<div ng-repeat="record in databaserecords">
Each of the records has a record.checked property and I want to handle all checked records together in one Bacon stream, for example to add a certain tag to all records at once.
At this point using $scope.$watchAsProperty(databaserecords) I get no Bacon events when checking or unchecking certain records, so how could I accomplish to receive these changes back in Bacon?
I might also mention, that using $scope.$watchAsProperty(property) out of ng-repeat, for example for input fields, works well without any problem.
Thanks for your help! :)
If I've understood correctly, your actual databaserecords remains the same throughout the scope, so you'll need to invoke $watchAsProperty with the objectEquality argument set to true:
$scope.$watchAsProperty("databaserecords", true)
By default angular opts to compare objects with a simple object equality check. In your case the list object remains the same, so a deeper check is necessary. This is already implemented in angular-bacon but it seems I've omitted it from the docs.

Having a set of checkboxes map to a nested array

I am working on a SPA that pulls in customer data from one $resource call, and gets some generic preference data from another $resource call.
The preference data is sent as an array, which I want to use to populate a series of checkboxes, like so:
<div ng-repeat="pref in fieldMappings.mealPrefs">
<input type="checkbox"
id="pref_{{$index}}"
ng-model="customer.mealPrefs"
ng-true-value="{{pref.name}}" />
<label class="checkbox-label">{{pref.name}}</label>
</div>
When a user clicks one or more checkboxes, I want the values represented in that array of checkboxes to be mapped to an array nested inside a customer object, like so:
.controller( 'AppCtrl', function ( $scope, titleService, AccountDataService ) {
// this is actually loaded via $resource call in real app
$scope.customer = {
"name": "Bob",
"mealPrefs":["1", "3"]
};
// this is actually loaded via $resource call in real app
$scope.fieldMappings.mealPrefs = [
{'id':"1", 'name':"Meat"},
{'id':"2", 'name':"Veggies"},
{'id':"3", 'name':"Fruit"},
{'id':"4", 'name':"None"}
];
});
I have tried setting up ng-click events to kick off functions in the controller to manually handle the logic of filling the correct part of the customer object model, and $watches to do the same. While I have had some success there, I have around 2 dozen different checkbox groups that need to be handled somehow (the actual SPA is huge), and I would love to implement this functionality in a way that is very clean and repeatable, without duplicating lots of click handlers and setting up lots of $watches on temporary arrays of values. Anyone in the community already solved this in a way that they feel is pretty 'best practice'?
I apologize if this is a repeat - I've looked at about a dozen or more SO answers around angular checkboxes, and have not found one that is pulling values from one object model, and stuffing them in another. Any help would be appreciated.
On a side-note, I'm very new to plunkr (http://plnkr.co/edit/xDjkY3i0pI010Em0Fi1L?p=preview) - I tried setting up an example to make it easier for folks answer my question, but can't get that working. If anyone wants to weigh in on that, I'll set up a second question and I'll accept that answer as well! :)
Here is a JSFiddle I put together that shows what you want to do. http://jsfiddle.net/zargyle/t7kr8/
It uses a directive, and a copy of the object to display if changes were made.
I would use a directive for the checkbox. You can set the customer.mealPrefs from the directive. In the checkbox directive's link function, bind to the "change" event and call a function that iterates over the customer's mealPrefs array and either adds or removes the id of the checkbox that is being changed.
I took your code and wrote this example: http://plnkr.co/edit/nV4fQq?p=preview

Display n time ago on various items using jquery, [issue with new elements generated after the loading the DOM]

I am using Jquery plugin http://timeago.yarp.com/ for showing time.
Issue is timeago will not take effect for dynamically generated items.
$(document).ready(function() {
$(".timeago").timeago(); // works perfectly fine for the items which are loaded on page load
//$(".timeago").live(timeago()); // gives me an error ie timeago is not defined
//$(".timeago").live($(".timeago").timeago()); // gives me an error too much recursion.
jQuery.timeago.settings.allowFuture = true;
});
From some google search I got to know something ie:
Using live is the same as using bind, except that it is limited only to the events click, dblclick, keydown, keypress, keyup, mousedown, mousemove, mouseout, mouseover, and mouseup.
Now how can do it cause I dont have any click event? How can I bind this?
.live() and .bind() assign callbacks to event. In your case, you don't have an event to assign the function to and so it fails.
You can, in theory, assign your callback to a custom event. You will however have to manually trigger the event (using .trigger()) whenever your item is generated. For example:
$("abbr.timeago").live("timeago", function() {
$(this).timeago();
});
// ... and in the bit that generates your item
$new_item.trigger("timeago")
Demo: http://jsfiddle.net/ZjuW4/9
Of course, using .live() in this situation is purely academic and does not really serve a good purpose.
If you do have access to the code that's generating the items, you can simply chain in the call to .timeago() as the items are generated, i.e. http://jsfiddle.net/ZjuW4/3/
take a look in this topic
here was discussed how to put timeago on dynamically loaded items
for example the results of an ajax request.
Activate timeago on newly added elements only
PS: allowFuture does not have anything to do with putting timeago on newly created items on your page. it just allows dates in the future (f.e. "in 3 days", "next week")

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