angularjs display expression dynamically from controller value

Question

I am bad at explaining i hope you guys understand my requirements and help me out here.

I have a view with ng-repeat below

<div ng-repeat="item in allitems"> {{displaydata}} </div>

i have a controller with below data

$scope.allitems ={
1:{name:"car",price:"999",qty:8},
2:{name:"bag",price:"127",qty:2},
3:{name:"dog",price:"777",qty:3},
4:{name:"cat",price:"333",qty:4}
}
var displaychoice1 = "{{item.name}}" 
var displaychoice2 = "{{item.price}}"
$scope.displaydata = "I want " + displaychoice1 + " which cost " + displaychoice2 ;

I want users to be able to select the "fields" to output to the view instead of hardcoding what to display in the view.

Answer 1

$scope.allitems should be an array

$scope.allitems = [
  {name:"car",price:"999",qty:8},
  {name:"bag",price:"127",qty:2},
  {name:"dog",price:"777",qty:3},
  {name:"cat",price:"333",qty:4}
]

And on the html you can simply

<div ng-repeat="item in allitems">
  I want {{item.name}} which cost {{item.price}}
</div>

EDIT

Allowing users to select fields could be something like

On controller:

$scope.displaydata = function(item, field1, field2){
  return "I want " + item[field1] + " which cost " + item[field2]; 
}

On HTML:

<div ng-repeat="item in allitems">
   {{ displaydata(item, 'name', 'price') }}
 </div>

Where you could adapt name and price to come from variables you have

Answer 2

You can use ngoptions for it to allow user to select an option:

<select name="mySelect" id="mySelect"
      ng-options="item in allitems track by $index"
      ng-model="selectedOption">  </select>

I want {{selectedOption.name}} which cost {{selectedOption.price}}