Getting HTML elements by their attribute names

In jQuery this is so:

$("span['property'=v:name]"); // for selecting your span element

You can use querySelectorAll:

    document.querySelectorAll('span[property=name]');

Yes, the function is querySelectorAll (or querySelector for a single element), which allows you to use CSS selectors to find elements.

document.querySelectorAll('[property]'); // All with attribute named "property"
document.querySelectorAll('[property="value"]'); // All with "property" set to "value" exactly.

(Complete list of attribute selectors on MDN.)

This finds all elements with the attribute property. It would be better to specify a tag name if possible:

document.querySelectorAll('span[property]');

You can work around this if necessary by looping through all the elements on the page to see whether they have the attribute set:

var withProperty = [],
    els = document.getElementsByTagName('span'), // or '*' for all types of element
    i = 0;

for (i = 0; i < els.length; i++) {
    if (els[i].hasAttribute('property')) {
        withProperty.push(els[i]);
    }
}

Libraries such as jQuery handle this for you; it's probably a good idea to let them do the heavy lifting.

For anyone dealing with ancient browsers, note that querySelectorAll was introduced to Internet Explorer in v8 (2009) and fully supported in IE9. All modern browsers support it.