Question

I’m using jQuery for a dynamic content behavior on a website. I’ve got an error:

TypeError: $(“#id”).attr(“src”,
thisContent.attr(“data-attr”)).show is not a function

Firstly I thought that it was browser related, but it turns out that it isn’t. The error is on this line:

$('#id').attr('src', thisContent.attr('data-attr')).show();

Answer 1

If the second argument of .attr() is undefined the getter will be invoked.
Seems like the getter is invoked instead of the setter.

Getter:

$(...).attr(String) // returns String which has no method .show()

Setter:

$(...).attr(String, String) // returns jQuery object, which has method .show()

thisContent.attr('data-attr') might return undefined in some cases, and therefor the getter gets invoked instead of the desired setter method.