AngularJS how to get and edit calculated input ng-model value related to other input value -

i trying make currency exchange system spa based on angularjs.

there should several inputs currency data json (with ng-repeat) , convert currency rate depending on active input value.

{      "currencies": [              {                  "name":"eur",                   "rate": 1,                  "active": "no"              },{                  "name": "pln",                  "rate": 4.1028,                  "active": "no"              }, {                  "name": "usd",                  "rate": 1.1239,                  "active": "no"              }          ]  }

<div ng-repeat='cur in main.currencies'>          <label>{{cur.name}}</label>          <input type="number" min="0"               ng-model="cur.result"               ng-init='cur.result = ""'              ng-click='main.clear();'              ng-focus='main.active = cur; cur.active = true';              ng-blur='cur.active = false';          >  </div>

how input 1 value on active (focused) input , calculated values on other inputs. new angularjs , want learn practical exercises.

other values should follow such logic: cur.value = main.active.value / main.active.rate * cur.rate.

but if try instead of ng-model="cur.result":

ng-model="cur.result = main.active ? cur.result : cur.result/main.active.rate*cur.rate" 

i can't write in input

maybe miss ng*... in input properties, far know if use ng-model should not use ng-name , ng-value...

try js:

angular.module('app',[]); angular.module('app').controller('ratectrl', ratectrl); function ratectrl($scope){     var vm = $scope;     vm.cur = {};     vm.currencies = {/* object */}     vm.setrate = function(model, rate){       return // javascript      } } 

the html

<div ng-controller="ratectrl main">     <div ng-repeat="currency in main.currencies">         <label>{{currency.name}}</label>         <!-- fyi, in ng-repeat there isolated scope. '$parent.' must come before objects outside ng-repeat -->         <input ng-model="main.cur.result" ng-focus="main.setrate(main.cur.result, currency.rate)">     </div> </div> 

this 1 basic way manipulate ng-model object. alternatives include using angular's filters, watchers, or decorators.