I would go with transient. The reason I would choose transient it is they are created exactly for your case. I know that you have your own removal functionality but why to repeat yourself? Another advantage would be that transient beneath use cache. If for some reason your will need to install object cache your … Read more
imagecreatefrom* functions return an image resource identifier, which when cast to a string (saving an option) will result in an empty string(0) “” container. Raw images created by these functions do not have any specific data structure that can be serialized out of the box. Two solutions I can think of: image files Use imagepng, … Read more
Transients do not expire if expiration time is not provided. Note that you can inadvertently cause this if you provide zero value for the time. You should be aware that this still doesn’t guarantee transient will stay alive. That’s shouldn’t be relied on. As a core implementation detail it will delete all database transients on … Read more
Default Transient API behavior is to use Options API for storage and so behavior identical to options. However if there is external object cache (declared by plugin or whatever) then they get stored using object cache functions instead. So basically it will work in scope of current site, unless there are plugins that make it … Read more
set_transient() using wp_cache_set() and mysql database. WP Cache API using $GLOBAL(global session for application). Cookies and Session saves data only for one current user(cookies in browser, sessions on backend). I think better using set_transient(), it has nice hooks and save all data global, even on site disabled cache.
According to this ticket: Cannot serialize object wrapping 3rd party library structs. Must serialize the xml (to a string) and store that to session and reload the xml when restoring from session When you are storing object in transient it gets serialized and not all objects are capable of that correctly. Store textual XML data … Read more
Custom field data is stored in the postmeta table, and it’s likely that scanning through this table is causing slowness. You should: install the debug bar plugin which will give you more insight into the queries that are being executed against the database – you’ll be able to see how long each query takes, and … Read more
Does it have to use a switch? why not something like this: if ( false === ( $value = get_transient( ‘value’ ) ) ) { // this code runs when there is no valid transient set } else { // this code runs when there is a valid transient set } If the a transient … Read more
A transient that doesn’t expire has a max name length of 53 characters yet a transient that does expire has a max name length of 45 characters. http://core.trac.wordpress.org/ticket/15058
Sorry for my late answer, but I found the solution for my problem. My Code was fine, also my small Test-Plugin. The problem is with the caching of my hosting provider. They are caching the Database requests and it took some time for the updater to recognize that the plugin is updated.