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How to handle drop-down lists with cascade / chain using multiple ng options

I am trying to get drop downs only for filling if something is selected over them. I had someone pointing me in the right direction with something like this.

<select class="selectLevel0" ng-model='scope1' ng-change='scope1Change()' 
        ng-options='obj.name for obj in array track by obj.id'>
</select>

<select class="selectLevel1" ng-model="scope2"  ng-change='scope2Change()' 
        ng-options='obj.name for obj in array2 track by obj.id' ng-hide='!scope1'>
</select>

<select class="selectLevel2" ng-model="scope3" ng-change='scope3Change()' 
        ng-options='obj.name for obj in array3 track by obj.id' ng-hide='!scope2'>
</select>

<select class="selectLevel3" ng-model="scope4" ng-change='scope4Change()' 
        ng-options='obj.name for obj in array4 track by obj.id' ng-hide='!scope3'>
</select>

<select class="selectLevel4" ng-model="scope5" 
        ng-options='obj.name for obj in array5 track by obj.id' ng-hide='!scope4'>
</select>

This is great for the first round - the drop-down values ​​will not be filled until something is selected in the previous one. It’s hard for me to understand if I can say that I have chosen all the way to the fifth, and I am moving to the second level. Then I want the third level to appear and 4-5 to disappear. I thought maybe something like ng_show = "! Scope2 ||! Scope3" (or something like that when I pass a few arguments), but I can not get something like this to work in angular. Is there a better way to handle this?

+1
1

, , , . ng-repeat, 2D.

: -

//It does not matter where i get the data from 
$scope.selects = [[{name:'level11', id:1}, {name:'level12', id:2}, {name:'level13', id:3}], 
    [{name:'level21', id:1}, {name:'level22', id:2}, {name:'level23', id:3}],
    [{name:'level31', id:1}, {name:'level32', id:2}, {name:'level33', id:3}],
    [{name:'level41', id:1}, {name:'level42', id:2}, {name:'level43', id:3}],
    [{name:'level51', id:1}, {name:'level52', id:2}, {name:'level53', id:3}]];

: -

$scope.selected = Array.apply(null, { length: $scope.selects.length }).map(Object);

changehandler, , .

 $scope.handleChange = function(index) {
     //reset data for others when a dropdown in selected
     $scope.selected = $scope.selected.map(function(itm, idx){
           return (idx > index) ? {} : itm;
     });

    //This will give you selected value of the current item if you need
    var selected = $scope.selected[index];
    //DO something with the value
  }

, , : -

<select ng-repeat="select in selects" ng-class="selectLevel{{$index}}"
         ng-change='handleChange($index)' <!-- Handler for Change event pass index of even model -->
         ng-model='selected[$index].value' <!-- Yes this is the model -->
         ng-show='!$index || selected[$index-1].value' <!-- Show only if its previous model has a value -->
         ng-options='obj.name for obj in select track by obj.id'>
</select>

+2

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