Angular JS - Automatically focus input and show typeahead dropdown - ui.bootstrap.typeahead

Question

I am using Angular JS - ui.bootstrap.typeahead:

I would like to click a button and focus an input field and automatically show the typeahead suggestion dropdown. I h

Answer 1

Updated:

I added the directive to github for easy updates and access. You can now install it as a dependency through bower.

Original post:

I came up with a pretty clean hack that does not require any changes to ui-bootstrap-tpls. The Idea is to use $setViewValue() to trigger the popup with a combination of a special filter comparator function.

In order to bypass the minLength check, $setViewValue() has to be set to a value longer than 1 so i'm using one space string. The role of the comparator function is to treat one space as a match to all items so they'll all show up when clicking on an empty input.

I created a simple directive:

angular.module('app')
.directive('typeaheadFocus', function () {
  return {
    require: 'ngModel',
    link: function (scope, element, attr, ngModel) {

      //trigger the popup on 'click' because 'focus'
      //is also triggered after the item selection
      element.bind('click', function () {

        var viewValue = ngModel.$viewValue;

        //restore to null value so that the typeahead can detect a change
        if (ngModel.$viewValue == ' ') {
          ngModel.$setViewValue(null);
        }

        //force trigger the popup
        ngModel.$setViewValue(' ');

        //set the actual value in case there was already a value in the input
        ngModel.$setViewValue(viewValue || ' ');
      });

      //compare function that treats the empty space as a match
      scope.emptyOrMatch = function (actual, expected) {
        if (expected == ' ') {
          return true;
        }
        return actual.indexOf(expected) > -1;
      };
    }
  };
});

Usage: