ng-if executes method continuously

Question

I have the following code:

data-ng-if="(fooCtrl.displayControl(1))

displayControl method return a true or false.

What I found is thatngif is constantly listening for this even after it has been evaluated once. How I found this, was by pointing a break point on the method. After a few F8(in debugger), it will continue as normal.

Why is ngif is executing the method continuously?

`ngIf` is evaluated each `$digest` cycle. Depending how big that method is - it could bog down the site. — tymeJV, Apr 11 '16 at 15:43

score 4 · Answer 1 · answered Apr 11 '16 at 15:53

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Angular runs each watcher function on each digest cycle, so this is normal that your function gets checked multiple times. If you don't want this behaviour you can consider one-time binding (Angular 1.3.x).

data-ng-if=":: fooCtrl.displayControl(1)"

answered Apr 11 '16 at 15:53

dfsq

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plus1 for one time binding info, thanks for your input! – Harry Apr 11 '16 at 16:32

score 2 · Accepted Answer · edited May 23 '17 at 10:28

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All your built-in directives will be triggered in every $digest cycle, see more about angular digest cycle here and here

so be aware of using directives like ng-show or ng-if and don't make them listen on a function that does a lot of processing or function that have some loops and that kind of stuff, keep them listening on already determined booleans or simple functions

edited May 23 '17 at 10:28

Community

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answered Apr 11 '16 at 15:48

amrdruid

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ng-if executes method continuously

2 Answers2