Add PHP version check for plugin.

[rahulsprajapati]

Description of the Change

Add minimum version check for the plugin before loading it. This will ensure plugin update doesn't break the site that don't match our minimum PHP version.

Closes #148

How to test the Change

1. Setup a WordPress environment running PHP 7.3
2. Install ads.txt plugin by downloading it with this feature branch.
3. Verify that plugin functionality doesn't load and you see an admin error message for php version. ( refer above screenshot in Description )

Changelog Entry

Fixed - Better error handling for environments that don't match our minimum PHP version

Credits

Props @dkotter, @rahulsprajapati

Checklist:

• I agree to follow this project's Code of Conduct.
• I have updated the documentation accordingly.
• I have added tests to cover my change.
• All new and existing tests pass.

[jeffpaul]

@peterwilsoncc looking for review here, thanks!

[peterwilsoncc]

The version check works as expected but I've included a couple of notes inline, the main issue is avoiding the potential for syntax errors triggering fatals.

[peterwilsoncc]

As the translation doesn't include HTML, the kses call can be avoided by escaping the string.

Suggested change

	echo wp_kses_post(
	sprintf(
	/* translators: %s: Minimum required PHP version */
	__( 'Ads.txt requires PHP version %s or later. Please upgrade PHP or disable the plugin.', 'ads-txt' ),
	esc_html( adstxt_minimum_php_requirement() )
	)
	);
	printf(
	/* translators: %s: Minimum required PHP version */
	esc_html__( 'Ads.txt requires PHP version %s or later. Please upgrade PHP or disable the plugin.', 'ads-txt' ),
	esc_html( adstxt_minimum_php_requirement() )
	);

[frankiebordone]

Resolved here: 552f5a4

[peterwilsoncc]

To avoid an issue similar to 10up/simple-page-ordering#163, the lines below this will need to be moved to a new file and moved to a file within the inc folder.

This will allow for the code to be updated to use modern PHP syntax without throwing a fatal error in older versions of PHP due to a syntax error.

[frankiebordone]

Code moved here:

• 81173e7

Updates to function namespaces within new file:

• a38d118

Associated unit test update:

• fda1699

[frankiebordone]

@peterwilsoncc Your previous feedback items on this PR have been addressed! Note: Some E2E related jobs were not successful as per https://github.com/10up/ads-txt/actions/runs/7477337138 - do we typically ignore these?

CC: @jeffpaul

[dkotter]

Now that these functions have been moved to a file with a namespace, I'd suggest we remove any namespacing from the function names. This includes any of the tenup_ prefixes and could also remove some of the adstxt ones.

I'd suggest something like the following:

• tenup_display_ads_txt -> display_ads_txt
• add_adstxt_capabilities -> add_capabilities
• remove_adstxt_capabilities -> remove_capabilities
• tenup_ads_txt_add_query_vars -> add_query_vars

[frankiebordone]

Thanks @dkotter, I've made the suggested updates here: df602d2

[dkotter]

Note: Some E2E related jobs were not successful as per https://github.com/10up/ads-txt/actions/runs/7477337138 - do we typically ignore these

I have fixed these