Provide way for hosts to create a correctly labeled button or link to directly upgrade PHP

[kirasong]

At the moment, it's straightforward to change the link for more information for a user within the hosting upgrade metabox (see: ​make/core), but if hosts want to link users to immediately upgrade, the text "Learn more..." isn't appropriate for that action.

I think WordPress should either provide a way to do so, or a documented best practice to do so.

See ​this P2 comment and ​feedback in Slack for previous context.

[pento]

Let's look at this for 5.1.1.

[afragen]

At WordCamp Phoenix Contributor Day @aaroncampbell and I came up with this as a solution.

An environmental variable and/or a filter may be used to customize this button link, similarly to the customizable link for information on updating PHP in r44476

[afragen]

updated @since

[desrosj]

46074.2.diff​ worked great!

In 46074.3.diff​, I pulled the code that determines the URL into a separate function. This allows the URL to be retrieved and used in different contexts without the default button. The main use case I had in mind for this was a host filtering the information page URL to one within the WordPress admin with their own branding. They could then output the URL into a call to action on that page.

[afragen]

Patch looks good.

[SergeyBiryukov]

Two minor notes on 46074.3.diff​:

• "Update your site PHP" label looks a bit strange to me, what about just "Update PHP"?
• Having two primary buttons next to each other also looks a bit weird. Maybe "Learn more" should not have the button-primary class if there's a direct PHP update URL available?

[afragen]

@SergeyBiryukov also consider the situation where the host may have another link for Learn more. $46044

[lukecarbis]

This diff includes the suggested text change to "Update PHP". Other than that, it's identical to the previous one.

[desrosj]

This looks good. Let's commit it and we can iterate on the button styles later.

[desrosj]

In 44814:

General: Add a way to specify a direct link for a user to update PHP.

A direct URL to where a user can update PHP for their website can now be specified in one of two ways:

• Defining the WP_DIRECT_UPDATE_PHP_URL environment variable.
• Returning a URL to the wp_direct_php_update_url filter.

When a URL is specified, an additional “Update PHP” button will be displayed at the bottom of the Core dashboard widget informing administrators that their site is running an outdated version of PHP (see [42832]).

Fixes #46074.
Props afragen, desrosj, lukecarbis.

[desrosj]

Reopening to backport.

[desrosj]

In 44815:

General: Add a way to specify a direct link for a user to update PHP.

A direct URL to where a user can update PHP for their website can now be specified in one of two ways:

• Defining the WP_DIRECT_UPDATE_PHP_URL environment variable.
• Returning a URL to the wp_direct_php_update_url filter.

When a URL is specified, an additional “Update PHP” button will be displayed at the bottom of the Core dashboard widget informing administrators that their site is running an outdated version of PHP (see [42832]).

Merges [44814] to the 5.1 branch.

Fixes #46074.
Props afragen, desrosj, lukecarbis.

[birgire]

I noticed that @since 5.1.1 is missing from the doc block of the wp_get_direct_php_update_url() function in changeset:44814 and changeset:44815.

[desrosj]

Thanks, @birgire! I will add that now.

[desrosj]

In 44829:

General: Add missing @since annotation for wp_get_direct_php_update_url().

Missed in [44815].

Props birgire.
See #46074.

[desrosj]

Add missed @since annotation to the 5.1 branch.

[SergeyBiryukov]

46074.5.diff​ looks good to me for backporting.

[jorbin]

In 44831:

General: Add missing @since annotation for wp_get_direct_php_update_url().

Backports [44829] to 5.1 branch. Dev-reviewed by desrosj and SergeyBiryukov.

Missed in [44815].

Props birgire.
See #46074.