javascript - Angular Directives: I have to call $apply twice? -

here's deal. have page edit user. has basic inputs , everything. created directive handle uploading of images through ajax:

angular.module('filedirectives', []) .directive('fileupload', ($http, $parse)->     scope:         fileupload: "="     link: (scope, element, attrs)->         if attrs.posturl             element.bind 'change', ->                 if this.files.length > 0                     form = new formdata()                     form.append 'files[]', file file in this.files                     req = new xmlhttprequest()                     req.open 'post', attrs.posturl, true                     req.onreadystatechange = =>                       if req.readystate 4                         if req.status 200                             response = json.parse req.responsetext                             notarray = attrs.notarray "true"                             if notarray                                 response = response[0]                             scope.fileupload = response                             scope.$apply()                     req.send form 

the directive used this:

<input type="file" file-upload="member.image" post-url='/members/images' not-array="true"/> 

everything working fine, wanted user's image in it's own component, created directive so:

<member-img member='member' ></member-img> 

which uses member's name , image display figure. if it'll help, here's directive:

    ).directive('memberimg', ()->     scope:         member: "="     restrict: "e"     templateurl: 'partials/member-image.html'     link: (scope, element, attrs)->         failed = false         setimage = ->             scope.image = if scope.member.image , scope.member.image isnt '' , not failed                 scope.member.image             else                 "default.gif"         setimage()         scope.$watch 'member.image', ->             failed = false             setimage()         element.find('img').bind 'error', ()->             scope.$apply ->                 failed = true                 setimage() ) 

anyways, reason putting it's own directory, image gets uploaded 50% of time. what's weirder in fileupload directive, if call $apply twice, works everytime:

.directive('fileupload', ($http, $parse)->     scope:         fileupload: "="     link: (scope, element, attrs)->         if attrs.posturl             element.bind 'change', ->                 if this.files.length > 0                     form = new formdata()                     form.append 'files[]', file file in this.files                     req = new xmlhttprequest()                     req.open 'post', attrs.posturl, true                     req.onreadystatechange = =>                       if req.readystate 4                         if req.status 200                             response = json.parse req.responsetext                             notarray = attrs.notarray "true"                             if notarray                                 response = response[0]                             scope.fileupload = response                             scope.$apply()                             scope.$apply() # reason have call twice.                     req.send form         else             throw "fileupload requires post-url attribute!" 

i think may happening on first apply, it's notifying parent scope member.image should change, on second apply parent scope's notifying other child member should change. however, know not intended behavior. light shed on subject appreciated.