Ya, you can do it that way, I just like to keep $watch for observer functions. You can do something similar for one-time init events using $on.
On Wed, Aug 5, 2015 at 12:33 PM, Kevin Shay <[email protected]> wrote: > Agreed that template bindings are preferable to directly watching where > possible, but that's not always the case. For one-time initialization you > can (and should) defend against the watcher getting called again by > removing it: > > var unwatch = scope.$watch('key', function (val) { > if (!val) { > return; > } > unwatch(); > ... > }); > > > On Wed, Aug 5, 2015 at 11:22 AM, Stewart Mckinney <[email protected]> > wrote: > >> The reason why this works is because ng-repeat uses $watchCollection >> internally to render its elements - this happens after your ( pre )link >> function. ( It effectively inserts a $compile step after linking ). >> >> So if you wait for a $digest, you ensure that $watchCollection fires, >> which means you get your DOM. >> >> There are some other ways to get around this. In this past I have done >> really simple things like using $last with ng-repeat to render a >> conditional element that simply fires an event on ng-init ( not the >> cleanest but the fastest if you don't want a custom directive ) or use a >> custom directive to fire an event in it's link function. You can also just >> access the parent controller via require and fire some init function in >> link, or just be very straightforward and move the third-party >> initialization into the custom directive's link function ( typically >> requiring it wrapped in an angular service ), avoiding the need for events, >> timeout, or require. >> >> >> I don't think that using $watch is a great idea. In general I try to stay >> away from using it directly - template bindings will often give me all I >> need. Using a feature which is meant to be used as an observer function in >> conjunction with model changes once for initialization purposes is asking >> for trouble in my opinion. I would worry, for instance, about that $watch >> firing twice and a third party JS library not being idempotent. >> >> >> There was some talk about having an "afterDigestLoop" event for Angular ( >> I forget the name of it , but there is a github issue open ), that would >> fire after $digest completely finishes that would be useful in a case like >> this. >> >> >> >> On Wed, Aug 5, 2015 at 10:31 AM, Kevin Shay <[email protected]> wrote: >> >>> If $timeout(..., 0) works in your case, then I agree that it's OK to >>> use, but I still think $watch() is the more idiomatic way of doing this. >>> Presumably in your finished application the data won't be hardcoded into >>> the controller; if it's coming from an asynchronous HTTP request, then >>> you'll have to set the timeout delay to some >>> hopefully-long-enough-but-not-so-long-it-slows-down-the-UI number of >>> milliseconds. With $watch(), Angular will take care of notifying your code >>> when the data is loaded and the variables are populated. >>> >>> Basically, I think the rule of thumb is that using $timeout with a 0 >>> delay to wait for the digest cycle to finish is fine, whereas using it with >>> a fudge-factor value to wait for something asynchronous should be >>> considered a hack, albeit one that's sometimes necessary when dealing with >>> libraries external to Angular. >>> >>> Kevin >>> >>> On Wed, Aug 5, 2015 at 3:42 AM, Sander Elias <[email protected]> >>> wrote: >>> >>>> Hi Andrew, >>>> >>>>> Am I correct in assuming that the reason $timeout works is because it >>>>> puts the closure at the end of the event loop queue so that all of the >>>>> angular binding functions have fired before the $timeout function is >>>>> executed? >>>>> >>>> That is indeed the case. It makes sure there is at least 1 $digest loop >>>> <https://www.ng-book.com/p/The-Digest-Loop-and-apply/> finished. >>>> >>>> Regards >>>> Sander >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "AngularJS" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> To post to this group, send email to [email protected]. >>>> Visit this group at http://groups.google.com/group/angular. >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "AngularJS" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To post to this group, send email to [email protected]. >>> Visit this group at http://groups.google.com/group/angular. >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "AngularJS" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at http://groups.google.com/group/angular. >> For more options, visit https://groups.google.com/d/optout. >> > > -- > You received this message because you are subscribed to the Google Groups > "AngularJS" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/angular. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "AngularJS" group. 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