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.
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
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;
}
}
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.
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:
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 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;
}
};
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.