CODEWITHSUNDEEP
javascriptangularjs
Douglas Gaskell
Douglas Gaskell

Reputation: 10030

AngularJS Expression From a String

Note: Similar to: angularjs execute expression from variable except I don't want to clutter up my scope with all the possibilities and data sets in use.

I want to be able to utilize pre-determined formulas in Angular's expressions.

Example:

  var config = {
    "Test": {
      name: "test",
      formula: true,
      formulaValue: "item['propertyOne'] + item['propertyTwo']"
    }
  }

<div ng-repeat="item in myArray">
  <span ng-if="config[item.name].formula">{{config[item.name].formulaValue}}</span>
</div>

Where the formula in formulaValue gets evaluated as if I typed it like:

<div ng-repeat="item in myArray">
  <span>{{item['propertyOne'] + item['propertyTwo']}}</span>
</div>

How would I accomplish this? It's not quite feasible to make a $scope function for each type of formula either, as these are setup in a config in fairly large quantities.

Upvotes: 0

Views: 124

Answers (1)

charlietfl
charlietfl

Reputation: 171679

Not the most ideal config setup but worst case you would need to use eval() which is not well liked due to security

Something like:

function parseConfig(item, configKey){
   if(config[configKey].formula){
      return eval(config[configKey].formulaValue);
   }
}
$scope.parseConfig = parseConfig;

Would put that in a service with your config but for now will just put on scope.

In view would be something like

{{parseConfig(item, 'Test')}}

If it was me I would prefer a config that looked something like

  var config = {
    "Test": {
      name: "test",
      formula: true,
      formulaType: 'concat',
      formulaValue: ['propertyOne','propertyTwo']
    }

then you would check formulaType and do what is needed with the properties in the formulaValue without using eval()

Upvotes: 1

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