Allow to use ‘as’ attribute on HTML ‘link’ element

[gszy]

This patch allows to use the as attribute by the HeadLink helper.

Citing from MDN:

Using as to specify the type of content to be preloaded allows the browser to:

• Prioritize resource loading more accurately.
• Match future requests, reusing the same resource if appropriate.
• Apply the correct content security policy to the resource.
• Set the correct Accept request headers for it.

[gszy]

@froschdesign, do you think that a unit test similar to https://github.com/zendframework/zend-view/blob/master/test/Helper/HeadLinkTest.php#L437-L444 would be enough?

[froschdesign]

@gscscnd

This patch allows to use the as attribute by the HeadLink helper.

The preload links are still work in progress. (Working Draft 2017-08-30)
We should not add this new HTML attribute, because it's too early and changes are possible.

We leave the issue open and add the label "WIP".

[gszy]

Ok, thank you for the explanation.

[froschdesign]

do you think that a unit test similar to https://github.com/zendframework/zend-view/blob/master/test/Helper/HeadLinkTest.php#L437-L444 would be enough?

Right!

[froschdesign]

Please add a comma after 'as'.

[thomasvargiu]

@froschdesign I need it too!

rfc5988 is not in draft stage anymore (candidate).

If browsers started implementing this feature, we should provide it too IMO.

[froschdesign]

@gscscnd

I need it too!

You can always extend the view helper or write your own. This allows you to use the attribute now.

If browsers started implementing this feature…

Do you have a status overview which includes this new attribute? Thanks!

[thomasvargiu]

You’re right, I can always use my own view helper.

About browser compatibility you can see it here

[froschdesign]

Next step is reached: "HTML 5.2 - W3C Recommendation, 14 December 2017"

[froschdesign]

Final step is reached: "HTML 5.2 is done"

This feature will be added with the next minor release. When? I don't know. At the moment I work on some other tasks / issues. I will try to clarify this.

Thanks for your patience!

[MatthiasKuehneEllerhold]

Any news on this? "as" is a critical part of the HTTP/2 Server Push via Apache http2 module.

[weierophinney]

Thanks, @gscscnd; merged to develop for release with 2.10.0.