Angularjs- adding/removing dynamic html elements (dropdown)

Question

here is my code- http://plnkr.co/edit/oTWXbLIKOxoGTd4U0goD?p=preview

1. why is the days dropdown does not data bind with scope.demoDays, it is always empty?

2. is this the correct way to add dropdown dynamically? If user adds 5 dropdown, how to get the results , will ng-model="selectedDay" create an array of selection? any suggestions?

Thank you

var app = angular.module('plunker', []);

app.controller('MainCtrl', function($scope, $compile) {

  var counter = 0;
  $scope.fields = [];

  $scope.days =['Day','Sun','Mon','Tue','Wed','Thu','Fri','Sat'];

    $scope.addField = function() {          
     $scope.fields.push({name:"test " + counter++});
    };
});



app.directive('demoDisplay', function($compile){
    return {
    scope:{
        demoDisplay:"=", //import referenced model to our directives scope
        demoDays:"="
      },
     link:function (scope, elem, attr, ctrl) 
      {
        scope.$watch('demoDisplay', function(){ // watch for when model changes

          elem.html("") //remove all elements

          angular.forEach(scope.demoDisplay, function(d){ //iterate list
              var s = scope.$new(); //create a new scope
              angular.extend(s,d); //copy data onto it
              console.log(scope.demoDays);

              var template = '<label class="item item-input"><div class="style-select"><select ng-model="selectedDay" ng-options="day for day in scope.demoDays"></select><br></div></label>';
              elem.append($compile(template)(s)); // compile template & append
          });
        }, true) //look deep into object
      }
    }
})

html

<button ng-click="addField()">Add Field</button>

<div demo-display="fields" demo-days="days"></div>

Solution

There is no need for $watch in your link function - you have already established two-way binding by specifying = on your scope property. And you can use a plain template, without having to compile.

templateUrl: 'template.html',

where template.html is:

<label class="item item-input">
  <div class="style-select">
    <select ng-model="demoDisplay.selection" ng-options="day for day in demoDays"></select>
    <br>
  </div>
</label>

Notice that the select is bound to demoDisplay.selection, which will be created on each field and be accessible on the parent scope via two-way binding. Also, note that within ng-options, I changed scope.demoDays to just demoDays. In a directive's template you only need to use the property's name to access a scope value.

You can use the directive inside ng-repeat to create additional fields when the button is clicked:

<div ng-repeat="field in data.fields">
  <div demo-display="field" demo-days="days"></div>
</div>

Here is a working plunker: http://plnkr.co/edit/pOY0l18W7wEbfSU7DKw2?p=preview

Comments

[Saghir A. Khatri]

please post code here, instead of referring to other sites. Thx

[msreekm]

copied js and html here. It is much easier to see JS code running in plnkr.

[Anthony Chu]

This change will make the dropdowns show up, but they are basically redrawn whenever the fields array changes and all selected values are lost.

[markstewie]

Yeah, there is definitely a better way of going about it. But this makes it work.

[msreekm]

Thanks for the explanation and simplifying the code !

[msreekm]

j.wittwer's answer keep's the selected values,thanks for the response.