Check.doWhen()

Perform a task when dependencies become available.

Syntax

Check.doWhen(dependencies, sdo, task[, lazy]);

Parameters

Parameter	Type	Notes	Util.js version
dependencies	Dependency Descriptor Object	The dependencies for the task.	1.0
sdo	Self Descriptor Object	The SDO of the script submitting the task.	1.0
task	Function String	Either: A function to run when the dependencies are met A string containing a file name to autoload when dependencies are met. Note: Autoloading must be enabled if you specify a file name to load. See Check.paths[] for more information.	1.0
lazy	Constant	By default, Check.doWhen() will attempt to autoload missing dependencies (except those marked as Check.NOT_LOADED). If you want to prevent autoloading, specify Check.LAZY_LOAD See Check.paths[] for more information on autoloading.	1.0

Return Values

Value

Type

Notes

Util.js version

true

Boolean

The dependencies were available and the task has been performed.

1.0

false

Boolean

One or more of the dependency checks failed and the task has not yet been performed.

The task will be queued until missing dependencies become available.

If one of the dependencies is marked as Check.NOT_LOADED and that file gets loaded, the task will be blocked from running.

1.0

<error>

Error

An error occurred, usually due to one of the following reasons:

Invalid parameters
A dependency specified Check.NOT_LOADED and the associated file was already loaded
The dependencies were all met and the task was processed, but the task generated an errror

1.0

Notes

The Check.doWhen() function is most commonly used for lazy loading diagnostic routines and unit tests, neither of which are not required for normal gameplay.

You can use the "loaddiag" or "loadtest" chat commands (part of Chat API) to load Diag API or Test API, as applicable, at any time during a game, which in turn will cause all the associated lazy-load scripts to be loaded.

You can run the "blocked" diagnostic (requires Diag API) to get a list of tasks that are blocked due to errors or presence of dependencies marked as Check.NOT_LOADED. You can also run the "blocked" diagnostic routine via the "diag blocked" chat command (requires Chat API).

Example

Note: In these examples, it's assumed the 'self' variable is already defined. For more information on that variable, see Self Descriptor Object.

Lazy load Diag.Cache.js when Diag.js becomes available.

Check.doWhen(
	{"Diag.js": true},
	self,
	"Diag.Cache.js",
	Check.LAZY_LOAD
);

Send chat message when Chat API becomes available...

Check.doWhen(
	{"Chat.js": true},
	self,
	function() {
		chat(0, "Let's chat...");
	},
	Check.LAZY_LOAD
);