错误对象没有方法

Question

My site loads dynamic js files on demand such as what pages are current displayed. But config file for all js libraries are every time load on every page. Everything works well for a time when some library is missing.

Script stop executing on error line.

Sample:

$('id').library1({}); //This method doesn't exist

$('id2').library2({}); // This method is not executed

How do I execute a second object method when first object doesn't exist?

Answer 1

You would have to capture the error

try { $('id').library1({}); } catch(e){} 
$('id2').library2({}); 

or check to see if the method exists before you execute it

var elem = $('id');
if (elem.library1) elem.library1({});
$('id2').library2({}); 

Answer 2

Capture and log/suppress the first error you're receiving, to enable the second and any subsequent calls to be executed:

try{
    $('id').library1({});
}
catch(e) { console.log(e); /* capture, log, suppress error. */ }

$('id2').library2({});

Answer 3

Test for the existence of the method before trying to call it (and triggering an exception):

if (typeof $.fn.library1 == "function")
    $('id').library1({});
else
    ; // in case the method doesn't exist

// this method is still executed
$('id2').library2({});