如何将值传递给angularjs指令？

Question

I have a directive that I want to pass a value, but it does not work:

<p>{{testvar}}</p>
<my-fn info="{{testvar}}"></my-fn>

app.directive('myFn', function() {
    return {
        restrict: 'E',
        templateUrl: 'templates/my-fn.html',
        scope: {
            info: "=info"
        }
    };
});

my-fn.html:

<p>the value is: {{info}}</p>

Result: The value in <p> tag is shown correctly, but the my-fn directive is not shown and prints the following error in the console:

Error: [$parse:syntax] http://errors.angularjs.org/1.4.3/$parse/syntax?p0=%7B&p1=invalid%20key&p2=2&p3=%7B%7Btestvar%7D
J/<@http://code.angularjs.org/1.4.3/angular.min.js:6:416

Answer 1

To answer my own question: one has to neglect the curly brakets as follows:

<my-fn info="testvar"></my-fn>

If anyone knows why , please comment below.