Remove section on Persistent Variables

Until Drupal 7 is still supported, that part is not obsolete.

It should at least be changed to say it only applies to D7.

variable_get() and variable_set() are Drupal 7 functions. While it is not explicit that is about Drupal 7, and it could be made explicit, that should not be cause of misunderstanding so much to require a change before Drupal 7 stops to be supported.

I have updated this issue to use the new Coding standard template. We are finding it very helpful.

quietone → credited Cyril42 → .

I found a duplicate of this. It is suggesting;

Maybe add a link to https://www.drupal.org/docs/8/api/state-api/overview → and add some examples.

.

I have closed that and am adding credit here.

Now that Drupal 7 is EOL, I think it is safe to remove all references to Drupal 7 specific standards.

Add link to section to remove

Rather than removing that part, it should be updated to mention classes, methods, or functions the supported Drupal releases support.

There isn't an exact replacement, and in any case, that's information about Drupal's APIs -- it doesn't belong in the coding standards.

Truly, it is not an API requirement, since a module could call variable_del() using a name for a persistent variable that module didn't define. Similarly, the state API, which is one of the replacements for the persistent variables API, does not require a module to use a specific state name.

Is there any convention for the naming of State keys?

The state key names used by Drupal core modules are prefixed by the module machine name followed by a period. Examples of those keys are system.cron_last, or comment.node_comment_statistics_scale.

Similar convention is used for the configuration object names. From automated_cron.settings, I gather the machine name of the module defining the configuration object.