Condition

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Condition
---
to be evaluated before running an action and skipped if the evaluation false.

Other uses of Conditions
--
LaunchCondition table -- while initializing an installation.
Feature and Components conditions -- individual featues/components to install or not.
UI features--how buttons,checkboxes and selection tree controls in UI behaves.

operand(property) operator operand(string/integer)
MYPROPERTY = "FOO"
MYPROPERTY = 15

Basic comparison operators
=,<>,<,>,>=,<=

"A"<"B"  -- true (dictionary order)

below operators only for strings.
>< True if left string contains right string
<< True if left string starts with right string
>> True if left string ends with right string

String comarisons are case-sensitive.
"A" = "a" --false
"A"~="a" -- true , with ~, it is not case-sensitive


logical operators
--
to combine multiple conditions

NOT PROPERTYNAME --- if property defined or not

   

Install State: Current State
Action State: planned install state when done

possible values of these states:

to execute an action if a feature is being installed
&MyFeature=3

This will compare feature action state with INSTALLSTATE_LOCAL

Built-In properties we can use in conitions,some of them below:
Installed - set if product is installed locally
REMOVE-set during uninstallation
we need to frame say product is not installed then condition: (NOT Installed )