Add functions to extract a URL from an arbitrary string, HTML, or the current $post

[wonderboymusic]

Scenarios

My post has a format of "link"

• My post has format meta for URL
• OR - My post content is a URL
• OR - My post contains an <a> tag with an href
• OR - My post content is a URL followed by new line(s) and commentary

An arbitrary string might be only a URL, a URL with some commentary, or a blob of HTML that might contain an <a> with an href attribute

Introduce the_link() and get_the_link( $id = 0 ) which will arbitrarily extract a URL from a post's content.

Introduce get_content_link( &$content, $remove = false ) to find a URL in an arbitrary string meeting the above criteria and optionally remove the found URL if it wasn't embedded in HTML content.

[helen]

Sort of Template, sort of Post Formats. Putting it in Post Formats for easy tracking of the feature dev.

[lancewillett]

For support of new functionality in default themes, see:

• Twenty Eleven: link post format - #23618
• Twenty Thirteen: link post format - #23619

[wonderboymusic]

attachment:23570.2.diff​​ is patch refreshed against trunk and tested compatibility for these 6 scenarios:

• Post with the link as the content
• Post with the link as the content, followed by commentary
• Post with the link as the content AND has link meta value
• Post with the link as the content AND has link meta value, followed by commentary
• Post with the link as metadata, content is empty
• Post with the link as metadata, followed by commentary

If the theme supports structured-post-formats, nothing happens to the content.
The themer can use: the_link(), get_the_link(), and get_content_link( $content ) - all return a URL. get_content_link( $content ) only works if the link is in the post's body.

If the post has a post format of link, the compat runs whether the theme supports it or not.

[Frank Klein]

I tested the 23570.2 patch as part of #23619 and there was a very small issue with the get_content_link when the content is HTML. The regular expression for detecting the link was incorrect (it's (.+?) instead of (.?)).

So here's the .2 patch with this very small change.

[nacin]

get_content_link() really super needs unit tests for all of the scenarios covered. This is a textbook case where tests can drive development.

[wonderboymusic]

Updated patch to always return empty string, makes all attached UNIT TESTS pass

[Mamaduka]

I think we should use esc_url() instead of esc_url_raw() in get_content_link(), because second function is not safe to use for displaying the URL.

​http://codex.wordpress.org/Function_Reference/esc_url_raw

[helen]

Replying to Mamaduka:

I think we should use esc_url() instead of esc_url_raw() in get_content_link(), because second function is not safe to use for displaying the URL.

Function could be used for purposes other than display. the_link() could probably stand to do esc_url(), though.

[wonderboymusic]

Updated to use *_url instead of *_link func names

[markjaquith]

In 23773:

Add functions to extract a URL from an arbitrary string, HTML, or the current $post

props wonderboymusic. see #23570

[markjaquith]

What about filters? What if I have an existing postmeta key that stores URLs. Would be nice to be able to filter get_the_url() and have that old data considered.

[helen]

Yeah, let's definitely get some filters in.

[helen]

23570.5.diff​ adds a filter to get_the_url(), corrects a little doc, and checks for the quote format as well as link. Do we need anything in get_content_url()? I guess I could see somebody wanting that.

[helen]

In 23775:

Add a filter for get_the_url(). Make sure get_the_url() also checks for the quote post format, as it currently has a URL field. see #23570.

[helen]

Leaving open - have a suspicion some things might shift when we actually start practical integration into Twenty Thirteen.

[lancewillett]

Fix parameter order of in_array() call

[lancewillett]

Quick patch to fix order of in_array() parameters: 23570.6.diff

[SergeyBiryukov]

In 23789:

Fix order of in_array() parameters. props lancewillett. see #23570.

[wonderboymusic]

In 1261/tests:

Add initial tests for . See #23570

[ryan]

In 1330/tests:

Update test_get_url_in_content() to reflect changes in get_url_in_content().

see #23570