Allow pjax with "data-pjax" with no value in yii.js

[arogachev]

I found this issue during writing tests for yii.js.

After 9807b2e we lose the ability to have pjax links like

<a data-pjax href="#">

or

<a data-pjax="" href="#">

(which is essentially the same).

This is because of:

pjax = $e.data('pjax') || 0,

"" || 0 resolves to 0.

This condtradicts with confuring pjax described in the docs for example here:

Or try this selector that matches any <a data-pjax href=> links inside a <div data-pjax> container.

I think that the older behavior - pjax !== undefined && pjax !== 0 && $.support.pjax is more correct, also note that @arisk sent the PR including this check in #12737 (383aa47), then it was ignored.

It will be better if we disable pjax only if data-pjax attribute is set to 0 only:

usePjax = pjax !== undefined && pjax !== 0 && $.support.pjax,

Note however that this check in Yii2 pjax adaptation:

// Ignore links with data-pjax="0"
if ($(link).data('pjax') == 0) {
    return;
}

needs to be modified accordingly too, because "" == 0 will evaluate to true.

Can be:

$(link).data('pjax') === 0)

(data returns 0 as number).

Or in case of a string which is returend by attr for example:

$(link).attr('data-pjax') === '0'

Or maybe even better:

parseInt($(link).data('pjax')) === 0

Note: I already fixed it in yii.js in PR containing tests for yii.js. PR will be sent soon.

[samdark]

Agree that it should be fixed as you've described.

[Mirocow]

Substituting this