This displays an update notice if a new version of LittleLink Custom has been released.
This one is definitely a messy one. Everything I added is commented, but I'm going to try explaining it here one more time.
General outcome:
• This feature checks the local version against the newest version stored on a separate server.
Error prevention:
• I used 'file_get_contents' to get the version number from a JSON file. If 'file_get_contents' cant find the file, PHP will throw an Error Exception.
• To prevent this, I put the update section in an if-statement that only applies if the following conditions are met.
Check if files exist:
• To test whether the file on the server exists (remember, if the server can't be reached, you will get an Error Exception) I used a function that checks if the URL to the file on the server successfully returns a '200 OK' response (see https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/200).
• If this condition is met, it sets the variable '$ServerExists' to true, if not to false.
• Now, the previous mentioned if-statement simply checks if the local file exists and the '$ServerExists' variable equals 'true' to proceed.
Get version number:
• If all previous conditions are met, two variables get defined via 'file_get_contents' '$Vgit' and '$Vlocal'.
• Both the file on the server and the local file simply contain the version number.
• The variable '$Vgit' is the newest version number retrieved from the server.
• The variable '$Vlocal' is the local version number.
Display update notice:
• To finally display the version number (added with HTML) one last check via an if-statement is performed. This simply checks if the current user is an admin AND if the version retrieved from the server is higher than the local one.
• If both conditions are met, the notice is displayed.
In addition, I should mention that I put the existing 'Watch Page' link as well as the update notice in a div with the class 'row' to display both links next to another instead of them being stacked.