jQuery Forum

selector to check if a tag has any attributes?
[2Replies]
- 15-Mar-2010 11:08 AM
- Forum: Using jQuery
In trying to select elements that have any attributes, the following throws a jQuery syntax error.

$("div[*]")

Is there a selector to check if a tag has any attributes?

Tested with jQuery 1.3

[jQuery] What is +new Date; in the function now()?
[2Replies]
- 11-Jun-2008 07:36 AM
- Forum: Using jQuery
I'm not familiar with the JavaScript syntax of "+new" in the now()
function in jQuery 1.2.5. Would you explain the plus (+) operator? How
does it work? What does it mean?
function now(){
return +new Date;
}
Is it the same as the following?
function now(){
return new Date();
}

unique identifiers after clone
[0Replies]
- 19-Feb-2008 04:48 PM
- Forum: Developing jQuery Core
This method makes the 'id' and 'name' attributes unique, which is very
useful after cloning. It updates 'for' attributes in 'label' tags as
well. The 'for' and 'id' will continue to match and, if 'id' and
'name' are the same (common in form field elements and anchor tags).
jQuery.fn.extend({
    // Correct uniqueness for all id attributes and assoc labels.
    // Correct uniqueness for all name attributes.
    makeIdentifiersUnique: function(makeUnique)
    // makeUnique: (optional) returns unique identifier given an
identifier (string)
    {
        var descendantOrSelf = this.find("*").andSelf();
        var strUniqueSuffix = Math.floor(Math.random() *
1679616).toString(36); // 4 digit alphanum
        makeUnique = ("function" == typeof makeUnique ? makeUnique :
function(id)
        {
            // Remove suffix of "_" 4-digit-alphanum (if it exists), then
append new suffix
            return id.replace(/_[0-9a-z]{4}$/,"") + "_" + strUniqueSuffix;
        });
        descendantOrSelf.filter("[id]").each(function()
        {
            this.id = makeUnique(this.id);
        });
        descendantOrSelf.filter("label").each(function()
        {
            this.htmlFor = makeUnique(this.htmlFor);
        });
        // caution: do not split id & name uniqueness code b/c for <a>, id
should equal name,
        // which won't be the case if the .random() function is called
twice.
        descendantOrSelf.filter("[name]").each(function()
        {
            try
            {
                if (jQuery.browser.msie)
                {
                    // Microsoft JScript allows the name to be changed at run time.
                    // HOWEVER!
                    // This does not cause the name in the programming model to
change
                    // in the collection of elements, but it does change the name
used
                    // for submitting elements. The NAME attribute cannot be set at
run time
                    // on elements dynamically created with the createElement
method.
                    // To create an element with a name attribute, include the
attribute
                    // and value when using the createElement method.
                    var strHTML = this.outerHTML + "";
                    strHTML = strHTML.replace(new RegExp("name=" + this.name, "g"),
"name=" + makeUnique(this.name));
                    jQuery(this).replaceWith(strHTML);
                }
                else
                {
                    this.name = makeUnique(this.name);
                }
            }
            catch (ex)
            {
                // ignore
            };
        });
        return this;
    }
});
Please consider adding this to the jQuery library.

clone to copy form field values
[6Replies]
- 19-Feb-2008 04:13 PM
- Forum: Developing jQuery Core
This code snippet, when added to the clone() method copies form field
values. Tested with IE 7 and FF 2 on Windows.
        // Copy .value and .checked attributes of form fields
        var dstFormElements = ret.find("*").andSelf().filter(":input");
        if (dstFormElements.length > 0)
        {
            var srcFormElements = this.find("*").andSelf().filter(":input");
            dstFormElements.each(function(i)
            {
                $ektron(this).val( srcFormElements.eq(i).val() );
                if ("checkbox" == this.type || "radio" == this.type)
                {
                    this.checked = srcFormElements.get(i).checked;
                }
            });
        }
Please consider adding it to the clone method in the next release of
jQuery.

Faster trim()
[4Replies]
- 18-Jan-2008 09:22 AM
- Forum: Developing jQuery Core
When testing performance of several JavaScript libraries, I came
across an unexpected result with the trim() method.
The jQuery library (as well as several others) trim using a single reg
exp replace.
(text || "").replace( /^\s+|\s+$/g, "" )
This seems reasonable. Why process the string twice when once will do?
However, using two reg expressions is signifanctly faster. That is,
each regular expression is very simple (no '|') and therefore runs
much faster, making up for processing the string twice.
(text ? text.replace(/^\s+/g,"").replace(/\s+$/g,"") : "")
Timing was done using Firebug (Firebug Lite for IE) on a Windows XP
machine w/ Firebug 2 and IE 7.
The test page is included here.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://
www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>JavaScript Library Test of 'trim'</title>
<script type="text/javascript" src="/jsunit/app/jsUnitCore.js"></
script>
<script type="text/javascript" src="/firebug/firebug.js"></
script>
<script type="text/javascript" src="/jquery-1.2.1.js"></script>
<script type="text/javascript">

</script>
</head>
<body>
<h2>JavaScript Library Test of 'trim'</h2>
<script type="text/javascript">

</script>
</body>
</html>

Response title

Attachments

jQuery Forum

Activity Trend