javascript - Selected value for angular select not be set on page refresh -

the selected value of angularjs select not being set on page refresh.

• it is set if navigate different view , navigate again.
• the model select saved local storage , initialized scope onload.
• i have checked data in scope same in 2 situations of navigating away , again, , refreshing page. data same.

after lot of investigation, see when select pristine, or when page refreshed, select list have blank option, first 1 below value ?:

<select ng-model="question.answer" class="form-control" ng-options="opt opt.value opt in question.options" >     <option value="?" selected="selected"></option>     <option value="0">1</option>     <option value="1">2</option> </select> 

note above html output. angular view has:

<select ng-model="question.answer" class="form-control" ng-options="opt opt.value opt in question.options" /> 

i'm not sure why preventing correct option being selected correct object still present @ question.answer. see simplified version of model below:

var question = {     options: [         {             id: 1,             value: "1"         },         {             id: 2,             value: "2"         }     ],     answer: {         id: 2,         value: "2"     } }; 

my understanding in ng-options, first opt specifies value should assigned variable specified in ng-model. in other words, assigning object in options array question.answer, rather value. can see looking @ model case.

but i'm not sure how angular use value in question.model determine option set selected.

i wonder if problem fact values of options set indices of question.options , can't work out question.answer index answer is.

so, guess questions are: - why correct option not being set when <option value="?" selected="selected"></option> present? - how angular determine how use model set selected option (aka - funny indices in option values?)

sorry post long. thank reading.

update: using chrome angularjs batarang extension, value being set question.answer picklist e.g.:

 {      $ref: $["options"][1]  } 

which means value of picklist "2".

so how using indices of options being used, how have set model? i.e. using $ref etc?

i edited answer after looked @ doing.

the ng-options attribute has track expression you're talking about:

ng-options="opt opt.value opt in question.options track opt.id" 

see updated fiddle: http://jsfiddle.net/ckleu/6/