ChatGPT解决这个技术问题 Extra ChatGPT

jQuery how to find an element based on a data-attribute value?

I've got the following scenario:

var el = 'li';

and there are 5 <li>'s on the page each with a data-slide=number attribute (number being 1,2,3,4,5 respectively).

I now need to find the currently active slide number which is mapped to var current = $('ul').data(current); and is updated on each slide change.

So far my tries have been unsuccessful, trying to construct the selector that would match the current slide:

$('ul').find(el+[data-slide=+current+]);

does not match/return anything…

The reason I can't hardcode the li part is that this is a user accessible variable that can be changed to a different element if required, so it may not always be an li.

Any ideas on what I'm missing?

you sure within your .find(el+[data-slide=+current+]); is the code that you write? it seems you missed some quotations to "[data-slide]"
That's what helped me to select all data attributes (regardless the value): $('*[data-slide]') You can use it with e.g. $('*[data-slide]').each( function() { ... });

F
Frédéric Hamidi

You have to inject the value of current into an Attribute Equals selector:

$("ul").find(`[data-slide='${current}']`)

For older JavaScript environments (ES5 and earlier):

$("ul").find("[data-slide='" + current + "']"); 

I worry that this won't work if data was added via jQuery .data(...) function, since this doesn't always render an attribute and soemtimes uses browser specific storage mechanism. Another reason that I wish jQuery core had a data specific selector.
Notice that it doesn't work for elements where you set data with $('#element').data('some-att-name', value); but only for those with hardcoded attribute. I've got this problem and to make it work set data by writing the attribute directly $('#element').attr('data-some-att-name', value);
J
John

in case you don't want to type all that, here's a shorter way to query by data attribute:

$("ul[data-slide='" + current +"']");

FYI: http://james.padolsey.com/javascript/a-better-data-selector-for-jquery/


For those of you who care, given the structure <ul><li data-slide="item"></li></ul> this answer's selector will return undefined so it does not work given the user's scenario. This answer WILL work for the structure <ul data-slide="item"><li></li></ul> While I understand why its popularity due to brevity, it is technically an incorrect answer. jsfiddle.net/py5p2abL/1
Just put a space between the ul and the brackets and it will work.
p
psycho brm

When searching with [data-x=...], watch out, it doesn't work with jQuery.data(..) setter:

$('<b data-x="1">'  ).is('[data-x=1]') // this works
> true

$('<b>').data('x', 1).is('[data-x=1]') // this doesn't
> false

$('<b>').attr('data-x', 1).is('[data-x=1]') // this is the workaround
> true

You can use this instead:

$.fn.filterByData = function(prop, val) {
    return this.filter(
        function() { return $(this).data(prop)==val; }
    );
}

$('<b>').data('x', 1).filterByData('x', 1).length
> 1

r
rap-2-h

Without JQuery, ES6

document.querySelectorAll(`[data-slide='${current}']`);

I know the question is about JQuery, but readers may want a pure JS method.


C
Community

I improved upon psycho brm's filterByData extension to jQuery.

Where the former extension searched on a key-value pair, with this extension you can additionally search for the presence of a data attribute, irrespective of its value.

(function ($) {

    $.fn.filterByData = function (prop, val) {
        var $self = this;
        if (typeof val === 'undefined') {
            return $self.filter(
                function () { return typeof $(this).data(prop) !== 'undefined'; }
            );
        }
        return $self.filter(
            function () { return $(this).data(prop) == val; }
        );
    };

})(window.jQuery);

Usage:

$('<b>').data('x', 1).filterByData('x', 1).length    // output: 1
$('<b>').data('x', 1).filterByData('x').length       // output: 1

// test data function extractData() { log('data-prop=val ...... ' + $('div').filterByData('prop', 'val').length); log('data-prop .......... ' + $('div').filterByData('prop').length); log('data-random ........ ' + $('div').filterByData('random').length); log('data-test .......... ' + $('div').filterByData('test').length); log('data-test=anyval ... ' + $('div').filterByData('test', 'anyval').length); } $(document).ready(function() { $('#b5').data('test', 'anyval'); }); // the actual extension (function($) { $.fn.filterByData = function(prop, val) { var $self = this; if (typeof val === 'undefined') { return $self.filter( function() { return typeof $(this).data(prop) !== 'undefined'; }); } return $self.filter( function() { return $(this).data(prop) == val; }); }; })(window.jQuery); //just to quickly log function log(txt) { if (window.console && console.log) { console.log(txt); //} else { // alert('You need a console to check the results'); } $("#result").append(txt + "
"); } #bPratik { font-family: monospace; }

Setup

Data added inline :: data-prop="val"
Data added inline :: data-prop="val"
Data added inline :: data-prop="diffval"
Data added inline :: data-test="val"
Data will be added via jQuery

Output


Or the fiddle: http://jsfiddle.net/PTqmE/46/


M
Matthew R.

I have faced the same issue while fetching elements using jQuery and data-* attribute.

so for your reference the shortest code is here:

This is my HTML Code:

<section data-js="carousel"></section>
<section></section>
<section></section>
<section data-js="carousel"></section>

This is my jQuery selector:

$('section[data-js="carousel"]');
// this will return array of the section elements which has data-js="carousel" attribute.

M
Matas Vaitkevicius

This selector $("ul [data-slide='" + current +"']"); will work for following structure:

<ul><li data-slide="item"></li></ul>  

While this $("ul[data-slide='" + current +"']"); will work for:

<ul data-slide="item"><li></li></ul>


V
Vini.g.fer
$("ul").find("li[data-slide='" + current + "']");

I hope this may work better

thanks


E
Emil

Going back to his original question, about how to make this work without knowing the element type in advance, the following does this:

$(ContainerNode).find(el.nodeName + "[data-slide='" + current + "']");