Creating custom tags

Lanat allows you to create custom tags to use in descriptions. A tag is basically just a parser that returns a string based on the value given to it.

Let's create a simple tag that all that does is return a string with the name of the user and a message if given.

Tutorial

Create a new class inheriting Tag and implement the parse method.
public class MyTag extends Tag { @Override protected String parse(NamedWithDescription user, String value) { return "My name is " + user.getName() + (value == null ? "" : " and I say " + value) + "!"; } }
The value parameter is the value given to the tag in the description after the = sign. If no value is given, it will be null.
Next register the tag so that Lanat is aware of its existence.
Tag.register("mytag", MyTag.class);
The first parameter is the name the user will have to use in the description, and the second is the class of the tag.
And that's it! Now you can use the tag in descriptions.
@Command.Define(description = "<mytag=Hello there>") class MyCommand extends CommandTemplate { }
The description of the command will be: My name is MyCommand and I say Hello there!

What is the user of a tag?

A tag can be present in a description of an element, which can be a command, an argument, group, etc. (Anything implementing NamedWithDescription)

When a description is parsed, the target it belongs to is passed to the tag when parse is called. This allows the tag to access this element and its properties.

Unregistering tags

You can unregister a tag by calling Tag.unregister with the name of the tag.

Tag.unregister("mytag");

This will remove the tag from the list of registered tags, and it will no longer be usable in descriptions. This can be useful to override an already registered tag with a new implementation, for example.

Last modified: 26 May 2024