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The if() statement allows a rule to be applied conditionally on the basis of the content of a variable store.

The if() statement can also be used to test the value of certain system stores, such as &platform.


if(storeName comparison store2) ... > ...
if(storeName comparison constant) ... > ...
if(&systemStore comparison store2) ... > ...
if(&systemStore comparison constant) ... > ...


The variable store to test.

The system store to test. The supported system stores are listed below; see associated topics for more detail:

  • &platform - test the platform the keyboard is running
  • &layer - test the currently visible layer on a touch keyboard
  • &baselayout - test the hardware base layout the user has configured
Either = or !=, for equal and not equal, respectively.
The name of a store to compare to
A string value to compare to


The if() statement allows any rule to be applied conditionally, depending on the content of store storeName, which can be defined either during keyboard configuration or dynamically by using a set() statement. The content of storeName is tested to see whether it matches (or does not match) a string or the content of another store, and the following rule used or ignored accordingly.

A variable store (used in an if(), set(), save() or reset() statement) should not also be used to match context or key, or output in a rule. (Note: this advice has changed from previous versions of Keyman. The compiler will warn on this misuse.)

Certain statements must appear in specific positions in the rule. The following order is enforced by the compiler:

  1. nul
  2. if(), baselayout() and platform()
  3. All other statements and characters


if(opt1 = '1') + any(letterGroup1) > index(outputGroup1,2)

The rule to output a character from the outputGroup1 store according to a keystroke matching a character in store letterGroup1 will only be applied if the content of store opt1 is exactly equal to the string '1'.

Where two or more separate options are held in stores, the different options can be tested together (logical "AND"):

if(opt1 = '1') if(opt2 = '1') + any(letterGroup1) > index(outputGroup1,3)

or separately (logical "OR"):

if(opt1 = '1') + any(letterGroup1) > index(outputGroup1,2)
if(opt2 = '1') + any(letterGroup1) > index(outputGroup1,2)

Applying a rule only on a specific platform (see also compile targets):

if(&platform = 'web') + any(letterGroup1) > index(outputGroup1, 2)


The if() statement can be used in keyboards on the following platforms.

Currently, only Windows and Linux support the options.htm form to set variable stores through a configuration user interface.

FeatureWindowsmacOSLinuxDesktop webMobile webiOSAndroid

Version history

The if() statement was introduced in Keyman 8.0.

Keyman 9.0: Added support for variable system stores.

Keyman for macOS 11.0.221 added support for if(), set(), save() and reset() for variable stores.

See also