AngularJS, how to bind a variable to concatenation of two other bound variables?

Question

I am new to AngularJS and trying to build an AngularJS practice app, in which, the user will concatenate a url from multiple inputs, i.e. protocol, domain, path, param1, param2,

Answer 1

You shouldn't assign scope variables in the view (the HTML) - it's only for reading them.

To make a new variable from inputs, add a ng-model to each of them and then in the controller define a method that makes a $scope variable from them e.g.

Your HTML form:

    
    
    
    {{makeUrl()}}

JS:

function MyCtrl($scope) {
    $scope.urlParts = {};
    $scope.urlParts.protocol = ""; 
    $scope.urlParts.domain = ""; 
    // etc... 
    // These values will be updated when the user types in the input boxes

    $scope.makeUrl = function() {
      return $scope.urlParts.protocol + "://" + $scope.urlParts.domain + $scope.urlParts.path + "?" + $scope.urlParts.param1 + "&" + $scope.urlParts.param2 + "&" + $scope.urlParts.param3;
    }
}