10 $digest() iterations reached. ng class? - angularjs

I am using a ng-class function in an element in ng-repeat. And I am getting this error. I am trying to pick a random class from the array. How do I solve this?
<div class="col-lg-4" ng-repeat="client in allClients">
<div class="someClass" ng-class="getClass()">
//some data
{{client.name}}
</div>
</div>
And this is my JS code.
$scope.getClass = function() {
var classArray = ['infobox1', 'infobox2', 'infobox3', 'infobox4', 'infobox5', 'infobox6'];
return classArray[Math.floor(Math.random() * classArray.length)];
}
The error goes on.
Watchers fired in the last 5 iterations: [[{"msg":"getBackgroundClass()","newVal":"infobox4","oldVal":"infobox6"},{"msg":"getBackgroundClass()","newVal":"infobox4","oldVal":"infobox5"},{"msg":"getBackgroundClass()","newVal":"infobox1","oldVal":"infobox4"},{"msg":"getBackgroundClass()","newVal":"infobox5","oldVal":"infobox1"},{"msg":"getBackgroundClass()","newVal":"infobox1","oldVal":"infobox4"},{"msg":"getBackgroundClass()","newVal":"infobox6","oldVal":"infobox4"},{"msg":"getBackgroundClass()","newVal":"infobox1","oldVal":"infobox5"},{"msg":"getBackgroundClass()","newVal":"infobox1","oldVal":"infobox2"},{"msg":"getBackgroundClass()","newVal":"infobox1","oldVal":"infobox4"}],[{"msg":"getBackgroundClass()","newVal":"infobox6","oldVal":"infobox4"},{"msg":"getBackgroundClass()","newVal":"infobox1","oldVal":"infobox4"},{"msg":"getBackgroundClass()","newVal":"infobox4","oldVal":"infobox1"},{"msg":"getBackgroundClass()","newVal":"infobox5","oldVal":"infobox1"},{"msg":"getBackgroundClass()","newVal":"infobox4","oldVal":"infobox5"},{"msg":"getBackgroundClass()","newVal":"infobox2","oldVal":"infobox6"},{"msg":"getBackgroundClass()","newVal":"infobox6","oldVal":"infobox1"},{"msg":"getBackgroundClass()","newVal":"infobox6","oldVal":"infobox1"},{"msg":"getBackgroundClass()","newVal":"infobox4","oldVal":"infobox1"

How often do you want to pick a random class? Currently, you have created an infinite loop because angular keeps noticing the class changed, runs a digest cycle to watch out for other changes, finds that the class changed again, runs a digest cycle to watch out for other changes, finds that the class changed again, and so on ...
You way want to pick the random value once, and stick with it for a while:
$scope.randomClass = classArray[Math.floor(Math.random() * classArray.length)]
(feel free to execute the above code as often as you want to see a new value)

Here is the working example
http://plnkr.co/edit/pl3W5uNofz123EJZnMT8
I made a classes array when I have the array with all my values in allClients, and then used that array to assign the classes
$scope.allClients = [{name: 'client'}, {name: 'client2'}, {name: 'client3'}];
var classes = $scope.allClients.map(function(client) {
var classArray = ['infobox1', 'infobox2', 'infobox3', 'infobox4', 'infobox5', 'infobox6'];
return classArray[Math.floor(Math.random() * classArray.length)];
});

Related

Mutating array within an array (Polymer iron-list)

I currently have an iron-list within another iron-list. The parent's data comes from a firebase-query element, and the child's data is computed from each parent item. The db structure and code looks a bit like this:
DB: [
category1: [
itemId1: {
price: 10,
title: "title"
}
]
]
<iron-list id="categoryList" items="{{categories}}" multi-selection as="category">
<template>
<div class="category-holder">
<iron-list id="{{category.$key}}" items="{{_removeExtraIndex(category)}}" as="item" selection-enabled multi-selection selected-items="{{selectedItems}}" grid>
<template>
<div class$="{{_computeItemClass(selected)}}">
<p>[[item.title]]</p>
<p>[[item.price]]</p>
</div>
</template>
</iron-list>
</div>
</template>
</iron-list>
After selecting any number of items, the user can tap on a fab to batch edit the price. This is where I'm having issues. I can't figure out how to access the correct child iron-list in order to call list.set...I'm currently trying the following very nasty method:
var categories = this.$.categoryList;
var categoryItems = categories.items;
(this.selectedItems).forEach(function(item) {
var index = item.itemId;
categoryItems.forEach(function(itemList, categoryIndex) {
if (itemList[index]) {
categories.set('item.' + categoryIndex + '.price', 10);
}
}, this);
}, this);
I'm iterating over the selected items in order to extract the item index and then iterating over the parent iron-list data (categoryItems) in order to check if the given item exists in that subset of data. If so, then I use the category index and attempt to call set on the parent iron-list using the given path to access the actual item I want to edit. As expected, this fails. Hopefully I've made myself clear enough, any help would be appreciated!
EDIT #1:
After much experimenting, I finally figured out how to correctly mutate the child iron-list:
(this.selectedItems).forEach(function(item) {
var list = this.$.categoryList.querySelector('#' + item.category);
var index = list.items.indexOf(item);
list.set(["items", index, "price"], 30);
}, this);
A couple of things worth noting. I'm using querySelector instead of the recommended this.$$(selector) because I keep running into a "function DNE" error. But now I have another problem...after calling the function, the value gets updated correctly but I get the following error:
Uncaught TypeError: inst.dispatchEvent is not a function
Here's a picture of the full error message:
I see the light, hopefully someone can help me out!
OK, I'll take a shot at this. I think the following happens, and I guess this based on how dom-repeat works:
var categories = this.$.categoryList;
var categoryItems = categories.items;
You take the variable that the iron-list is based on, but setting one array to another just creates a reference in javascript. As soon as you update categoryItems, you also update this.$.categoryList.items. When you later sets the new value, iron-list will do a dirty check and compare all subproperties, and because they are equal (because ... reference), the iron-list wont update the dom.
What you should do is to make sure it's a totally new copy and the way of doing that is to use JSON.parse(JSON.stringify(myArray)).
Further on, one major flaw I see in your code is that you're using querySelector to select an element, and then manipulate that. What you should do is to use this.categories and only that variable.
So your method should look something like:
// Get a freshly new array to manipulate
var category = JSON.parse(JSON.stringify(this.categories);
// Loop through it
category.forEach(category) {
// update your categoryList variable
}
// Update the iron list by notifying Polymer that categories has changed.
this.set('categories', category);

how to retrieve data nested in two collections from firebase with angular

I'm new in Angular - Firebase development, and I am having problems to understand how to retrieve data nested in two collections.
I have a collection named "Orders", which includes a field call "auth", which is the user ID, and I have another collection that is the "User Profile", wich it's $id is the value of "auth". Inside the User Profile I have a field named roomNumber, and it's content I that I want to retrieve every time I read, in ng-repeat of the Orders.
In my view I was trying to do something like this :
<tr ng-repeat="item in items | filter: searchKeyword ">
<td align="left">{{item.$id}} - {{roomNumber(item.$id)}}</td></tr>
roomNumber is a function in my controller
$scope.roomNumber = function(id) {
var rootRef = new Firebase("https://xxxx-fire-yyyy.firebaseio.com/userProfile"+ '/' + id);
$scope.userdet = $firebaseArray(rootRef);
rootRef.on("value", function(rootSnapshot) {
var key = rootSnapshot.key();
var childKey = rootSnapshot.child("room").val();
console.log("room ", childKey)
});
return childKey
}
When I run this code and see results in my js console, strange things happend:
1. It repeat a lot of times
2. I can never get the childKey value
I have been reading Firebase documentation, but really I do not understand how to do this "silly" thing, does anybody give me a tip of how to do it?
When you bind a function to the $scope and call it within the html it expects to get an answer back right away when called. So when you query firebase and it takes its sweet time getting you back an answer, angularjs has already gotten an answer of undefined from the function.
So what is happening is that you are registering a callback when you provide the function to rootRef.on and then right after you register the callback you are returning the value of childKey. Unfortunately, childKey only gets set by the callback function (which firebase hasn't executed yet). Therefore angularjs gets an answer of undefined from your roomNumber function.
In order to make this work, you are going to have to get the room numbers beforehand and then probably add them to each of your items in $scope.items then use
<td align="left">{{item.$id}} - {{item.room}}</td></tr>
instead of
<td align="left">{{item.$id}} - {{roomNumber(item.$id)}}</td></tr>
To load all the room numbers you could call some function like this one after $scope.items has loaded
for (var i = 0; i < $scope.items.length; i++) {
var rootRef = new Firebase("https://xxxx-fire-yyyy.firebaseio.com/userProfile"+ '/' + $scope.items[i].$id);
$scope.userdet = $firebaseArray(rootRef);
rootRef.on("value", function(rootSnapshot) {
var key = rootSnapshot.key();
var childKey = rootSnapshot.val().room;
$scope.items[i].room = childKey;
});
}
It would change each of the items to have a reference to the room. Unfortunately, that list wouldn't update as the data updates, so the better solution would be to do that same query in whatever function was getting your items from the server and add the room to each item as it was being added to the items list.
To fix the issue with childKey not reading you need to use this:
var childKey = rootSnapshot.val().room;
instead of this:
var childKey = rootSnapshot.child("room").val();
console.log("room ", childKey)
Reference: https://www.firebase.com/docs/web/guide/retrieving-data.html

angular ionic fails to update for some variables

In my Ionic / Angular framework I update 2 variables inside a service (an $http.get().then() block):
for( var di = day; di <= endOfMonthDate; di++) {
var flavor = days[di - 1];
daysLeftCalendar.push( flavor[1]); // dates right away !
}
var todaysFlavorIndex = -1;
for (var i = 0; i < days.length; i++ ) {
if ((days[i])[0] == day) {
todaysFlavorIndex = (days[i])[1];
todaysFlavorName = flavors[todaysFlavorIndex]; // only updates if you change tabs
}
}
Then I have these accessor methods in my service that get called by my controller:
return {
// both of these are hit after switching to one of the two tabs which both reference these functions
remainingFlavorIndexes: function() {
return daysLeftCalendar
},
getTodaysFlavorName: function() {
return todaysFlavorName
}
};
Then in my only controller I expose these variables like this:
$scope.remainingFlavorIndexes = Calendar.remainingFlavorIndexes(); // this one copies over right away !!
$scope.todaysFlavorName = Calendar.getTodaysFlavorName(); // this one doesn't
Then in my view:
<div> <!-- this one shows up right away -->
{{remainingFlavorIndexes}}
</div>
<div> <!-- these two only show up after switching tabs and returning -->
<img class="scaled-image" src="img/{{todaysFlavorName[2]}}">
</div>
<div style="text-align: center;">
{{todaysFlavorName[1]}}
</div>
How is it that I'm handling these 2 variables exactly the same, but todaysFlavorName is empty (even after the .then call returns)?
And why is it that when I switch tabs and come back they are populated?
Edit:
What is supposed to go into remaining flavor indexes is something like this:
[21,20,13,0,27,12,9,18,1,3,30,29,25,7,6,4,9,18,21,13]
And it works every time.
What is supposed to go into todaysFlavorName is:
[21, "peanut butter", "peanut_butter.jpg", "some meaningless text here"]
And it works only after I switch tabs.
There is a big difference between both. In the case of daysLeftCalendar:
the service has an array
the controller calls the service function that returns a reference to that array
the http callback function pushes elements to this array
So, the controller has a reference to the array that is in the service. Whenever the array is modified in the service, it's also modified in the controller, since the controller and the service both share a reference to the same array.
In the case of todaysFlavorName:
the service defines a variable todaysFlavorName referencing an array
the controller calls the service function that returns a reference to that array
the http callback function doesn't modify this array. It assigns a new array to the variable todaysFlavorName.
So, in the end, the controller has a reference to the original array, whereas the service has a reference to the new array. Which explains why nothing changes in the view: the controller still references the old array.
When you change tab, I assume the controller is reinstantiated, the service function is called again, and the controller gets back the new value from the service.
The fix is quite easy: always get the value to display from the service, instead of caching the value in the controller. Replace
$scope.todaysFlavorName = Calendar.getTodaysFlavorName();
by
$scope.todaysFlavorName = function() {
return Calendar.getTodaysFlavorName();
};
and
{{todaysFlavorName[1]}}
by
{{todaysFlavorName()[1]}}

Select Random Content Spot

I have 10 content spots. I would like a page to show 1 of them randomly.
I have tried using the Function 'ShowContentSpots' - but that shows all of them & doesn't cycle through.
What's the best way of doing this?
You should edit the ShowContentSpots function and:
change the code so that only one item is retrieved (not all)
add some randomizer when retrieving a single item
A quick solution would be:
#if (!string.IsNullOrEmpty(ContentSpotIds))
{
var rand = new Random();
var spotIds = ContentSpotIds.Split(',').Select(f=>new Guid(f));
var spots = Data.Get<Content.ContentSpot>().Where(f=> spotIds.Contains(f.Id)).ToList();
if (spots.Any())
{
var spot = spots[rand.Next(spots.Count)];
<div class="spots">
<div class="spot">
#Html.Raw(spot.Content)
</div>
</div>
}
}
Please note that this is part of the original function's code.
Here I added:
var rand = new Random();
and modified this part:
var spot = spots[rand.Next(spots.Count)];
<div class="spots">
<div class="spot">
#Html.Raw(spot.Content)
</div>
</div>
This is just a quick sample. So when you refresh the page very quickly the spot might not change every time - because we create a new Random object every time we refersh the page.
To avoid this, initialize the Random object only once and somewhere else, and use it in this function.

How to Troubleshoot Angular "10 $digest() iterations reached" Error

10 $digest() iterations reached. Aborting!
There is a lot of supporting text in the sense of "Watchers fired in the last 5 iterations: ", etc., but a lot of this text is Javascript code from various functions. Are there rules of thumb for diagnosing this problem? Is it a problem that can ALWAYS be mitigated, or are there applications complex enough that this issue should be treated as just a warning?
as Ven said, you are either returning different (not identical) objects on each $digest cycle, or you are altering the data too many times.
The fastest solution to figure out which part of your app is causing this behavior is:
remove all suspicious HTML - basically remove all your html from the template, and check if there are no warnings
if there are no warnings - add small parts of the html you removed and check if the problem is back
repeat step 2 until you get a warning - you will figure out which part of your html is responsible for the problem
investigate further - the part from step 3 is responsible for either mutating the objects on the $scope or is returning non-identical objects on each $digest cycle.
if you still have $digest iteration warnings after step 1, than you are probably doing something very suspicious. Repeat the same steps for parent template/scope/controller
You also want to make sure you are not altering the input of your custom filters
Keep in mind, that in JavaScript there are specific types of objects that don't behave like you would normally expect:
new Boolean(true) === new Boolean(true) // false
new Date(0) == new Date(0) // false
new String('a') == new String('a') // false
new Number(1) == new Number(1) // false
[] == [] // false
new Array == new Array // false
({})==({}) // false
Usually that happens when you're returning a different object every time.
For example, if you use this in a ng-repeat:
$scope.getObj = function () {
return [{a: 1}, {b: 2}];
};
You're going to get this error message because Angular tries to have the "stability" and will execute the function until it returns the same result 2 times (comparing with ===), which in our case will never return true because the function always returns a new object.
console.log({} === {}); // false. Those are two different objects!
In this case, you can fix it by storing the object in scope directly, e.g.
$scope.objData = [{a: 1}, {b: 2}];
$scope.getObj = function () {
return $scope.objData;
};
That way you're always returning the same object!
console.log($scope.objData === $scope.objData); // true (a bit obvious...)
(You should never encounter that, even on complex applications).
Update: Angular has added some more in-depth explanation on their website.
Just wanted to throw this solution in here, hopefully it'll help others. I was getting this iteration problem because I was iterating over a generated property which was making a new object every time it was called.
I fixed it by caching the generated object the first time it was requested, and then always returning the cache if it existed. A dirty() method was also added, which would destroy the cached results as needed.
I had something like this:
function MyObj() {
var myObj = this;
Object.defineProperty(myObj, "computedProperty" {
get: function () {
var retObj = {};
return retObj;
}
});
}
And here's with the solution implemented:
function MyObj() {
var myObj = this,
_cached;
Object.defineProperty(myObj, "computedProperty" {
get: function () {
if ( !_cached ) {
_cached = {};
}
return _cached;
}
});
myObj.dirty = function () {
_cached = null;
}
}
There also is the possibility of it not being an infinite loop at all. 10 iterations is not a sufficiently large number to conclude that with any amount of certainty. So before going on a wild-goose chase it may be advisable to rule out that possibility first.
The easiest method to do so is increasing the maximum digest loop count to a much larger number, which can be done in the module.config method, using the $rootScopeProvider.digestTtl(limit) method. If the infdig error does no longer appear you simply have some sufficiently complex update logic.
If you build data or views relying on recursive watches you may want to search for iterative solutions (i.e. not relying on new digest loops to be started) using while, for or Array.forEach. Sometimes the structure is just highly nested and not even recursive, there probably is not much to be done in those cases except raising the limit.
Another method of debugging the error is looking at the digest data. If you pretty print the JSON you get an array of arrays. Each top level entry represents an iteration, each iteration consists of a list of watch entries.
If you for example have a property which is modified in a $watch on itself it is easy to see that the value is changing infinitely:
$scope.vm.value1 = true;
$scope.$watch("vm.value1", function(newValue)
{
$scope.vm.value1 = !newValue;
});
[
[
{
"msg":"vm.value1",
"newVal":true,
"oldVal":false
}
],
[
{
"msg":"vm.value1",
"newVal":false,
"oldVal":true
}
],
[
{
"msg":"vm.value1",
"newVal":true,
"oldVal":false
}
],
[
{
"msg":"vm.value1",
"newVal":false,
"oldVal":true
}
],
[
{
"msg":"vm.value1",
"newVal":true,
"oldVal":false
}
]
]
Of course in larger project this may not be as simple, especially since the msg field often has the value "fn: regularInterceptedExpression" if the watch is a {{ }} interpolation.
Other than that the already mentioned methods, like cutting down the HTML to find the source of the problem, are of course helpful.
I had the same problem - I was creating a new date every time. So for anyone dealing with dates I converted all calls like this:
var date = new Date(); // typeof returns object
to:
var date = new Date().getTime(); // typeof returns number
Initializing a number instead of a date object solved it for me.
the easy way is :
use angular.js,not the min file.
open it and find the line:
if ((dirty || asyncQueue.length) && !(ttl--)) {
add line below:
console.log("aaaa",watch)
and then refresh your page, in the develope tools console,you will
find you error code .
It's a known bug in ui-router, this helped us: https://github.com/angular-ui/ui-router/issues/600
I would also like to mention that I received this error message when I had a typo in the templateUrl of a custom directive that I had in my project. Due to the typo, the template could not be loaded.
/* #ngInject */
function topNav() {
var directive = {
bindToController: true,
controller: TopNavController,
controllerAs: 'vm',
restrict: 'EA',
scope: {
'navline': '=',
'sign': '='
},
templateUrl: 'app/shared/layout/top-navTHIS-IS-A-TYPO.html'
};
Look in the network tab of your web browser's dev tools, and look to see if any resource is having a 404 error.
Easy to overlook, because the error message is very cryptic and seemingly unrelated to the real issue.
I was having this issue in my project because the .otherwise() was missing my route definition and I was hitting wrong route.
I had this issue because I was doing this
var variableExpense = this.lodash.find(product.variableExpenseList, (ve) => {
return ve.rawMaterial.id = rawMaterial.id;
});
Instead of this: (notice = vs ===), my unit test started breaking and I found my stupidity
var variableExpense = this.lodash.find(product.variableExpenseList, (ve) => {
return ve.rawMaterial.id === rawMaterial.id;
});
I ran into this issue where I needed a dynamic tooltip... it caused angular to recalculate it every time as a new value (even though it was the same). I created a function to cache the computed value like so:
$ctrl.myObj = {
Title: 'my title',
A: 'first part of dynamic toolip',
B: 'second part of dynamic tooltip',
C: 'some other value',
getTooltip: function () {
// cache the tooltip
var obj = this;
var tooltip = '<strong>A: </strong>' + obj.A + '<br><strong>B: </strong>' + obj.B;
var $tooltip = {
raw: tooltip,
trusted: $sce.trustAsHtml(tooltip)
};
if (!obj.$tooltip) obj.$tooltip = $tooltip;
else if (obj.$tooltip.raw !== tooltip) obj.$tooltip = $tooltip;
return obj.$tooltip;
}
};
Then in the html, I accessed it like this:
<input type="text" ng-model="$ctrl.myObj.C" uib-tooltip-html="$ctrl.myObj.getTooltip().trusted">
this is how I approached it and found a solution:
I checked the text, it showed:
Error: [$rootScope:infdig] 10 $digest() iterations reached. Aborting!
Watchers fired in the last 5 iterations: [[{"msg":"statement === statment && functionCall()","newVal":[{"id":7287,"referen...
so if you can see the
msg
that's the statment generating the error. I checked the function called in this message, I returned (false) from all of them just to determine which one have the problem.
one of them was calling a function that keeps changing the return, which is the problem.
As crazy as it sounds, I fixed this error just by restarting my browser when it just cropped up all of a sudden.
So one solution is to just clear your browser's cache or try restarting the browser.

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