angularjs expression in html <object> tag

As of AngularJS 1.1.4, you can use the ng-attr- prefix for the data attribute:

<object ng-attr-data="{{doc_details.file_url}}" type="application/pdf"></object>

See the ngAttr for binding to arbitrary attributes section on AngularJS: Interpolation and data-binding.

The problem here is that the browser is seeing

<object data="{{doc_details.file_url}}" type="application/pdf"></object>

in the DOM before Angular compiles it, and obviously {{doc_details.file_url}} isn't a valid URL.

Directives can be your friend here.

Say we want to write:

<pdf src='doc_details.file_url'></pdf>

We can create a directive:

app.directive('pdf', function() {
    return {
        restrict: 'E',
        link: function(scope, element, attrs) {
            var url = scope.$eval(attrs.src);
            element.replaceWith('<object type="application/pdf" data="' + url + '"></object>');
        }
    };
});

This will defer the creation of the object element until we actually have the URL available to us from the scope (assuming it's already there - otherwise you'd want to $watch the src attribute on the scope until it became available).

Here this is in a fiddle.