Check.has()

Check if a dependency is available, try and load it if not, return availability state...

Syntax

var available = Check.has(file[, ver[, lazy]])

Parameter

Type

Mandatory

Notes

Util.js version

file

String

Filename of dependency

1.0

ver

Number

Constant

Specify the required version of the file (exact match) or a version constant:

Check.ANY_VERSION – skip version check
Check.NOT_LOADED – disables autoloading of the file, fails dependency check if the file is already loaded

Default: Check.ANY_VERSION

For more information on autolaoding, see: Check.paths[].

1.0

lazy

Constant

By default, Check.has() will attempt to autoload missing dependencies.

If you want to prevent autoloading, specify Check.LAZY_LOAD

1.0

Value	Type	Notes	Util.js version
true	Boolean	The dependency check was successful.	1.0
false	Boolean	The dependency check failed.	1.0
<error>	Error	An error occurred, most likely invalid parameters.	1.0

Check specific version of file...

function bleh() {
  if (Check.has("foo.js", 1.2)) {
    // do it the foo.js v1.2 way
  } else {
    // do it without any foo
  }
}

Prevent autoloading foo.js...

function bleh() {
  if (Check.has("foo.js", 1.2, Check.LAZY_LOAD)) {
    // do it the foo.js v1.2 way
  } else {
    // do it without any foo
  }
}

You can get a list of all provided dependencies using Util API diagnostics (requires Diag API).

Requires:

Topics:

Tricks for including files — Some tricks with the include() function...
Dependency Descriptor Object — Define one or more dependencies for your script...
Check() — Perform a soft-check to see if a dependency is available...
- Check.basePath — The base path to the folder that contains the APIs folder...
- Check.paths[] — Define one or more folder paths to enable autoloading...
- Check.doWhen() — Perform a task when dependencies become available.
- Check.has() — Check if a dependency is available, try and load it if not, return availability state...
- Check.LAZY_LOAD — Disable autoloading during a dependency check...
- Check.required() — Thrown a descriptive error if dependency check fails...
- Check.NOT_LOADED — Indicates a script is not yet loaded, or must not be loaded, depending on the Check function being used...
- Check.ANY_VERSION — Skip version checking for a dependency check...
- Check.provide() — Indicate a file is now available.
- Check.versionOf() — Check the version of a dependency.
Self Descriptor Object — Define the filename and version of your script...