Test if element already has jQuery datepicker

Question

I have a form with many input elements. Some are date fields with a jQuery UI datepicker alraedy attached:

$("#someElement").mask("9?9/99/9999").datepicker({showOn: 'button', buttonText:'Click here to show calendar', duration: 'fast', buttonImageOnly: true, buttonImage: /images/calicon.gif' });

Then I have a key command bound to this function:

function openCalendar() {
    var selection = document.activeElement;

    // { Need to test here if datepicker has already been initialized 
        $(selection).datepicker("show");
    // }
}

This works great for elements which already have the datepicker on them. However any other fields will throw a javascript error. I'm wondering the best way to test to see if datepicker has already been initialized on that field.

Answer 1

Wow can't believe I missed this one. Line 108 of ui.datepicker.js:

/* Class name added to elements to indicate already configured with a date picker. */
markerClassName: 'hasDatepicker',

So I just need to test for hasClass('hasDatepicker'). This seems like the most straightforward way. Furthermore, this statement checks whether the datepicker is currently opened (for anyone who is interested):

if ($("#ui-datepicker-div").is(":visible") && $("#ui-datepicker-div").html() != "") {
    // datepicker is open. you need the second condition because it starts off as visible but empty
}

Answer 2

1) If the code throws an error when trying to open the datepicker, you can put the code into try..catch

2) You can set some data to the input field when initializing the datepicker

$("#someElement").data("datepicker-initialized", true);

3) You can use the data stored by datepicker plugin

if($("#someElement").data("datepicker") != null){
   // datepicker initialized
}

or

if($.data($('#someElement').get(0), 'datepicker')){
   // datepicker initialized
}

4) datepicker internally uses a function _getInst

if($.datepicker._getInst($('#someElement')[0]) != null){}

the method does almost the same as example 3.

Couldn't find any better solution.