!!! Conditions

At this page you can find the documentation for conditions. Conditions are an essential part of several markups, e.g. [rules | Doc Rules], [covering lists | Doc SetCoveringKnowledge], [abstraction tables | Doc AbstractionTable] and [test cases | Doc TestCaseTable]. Conditions are used to define a logical expression on some findings and/or outcomes of a d3web diagnostic session, to tell d3web how to action under specific circumstances.

!! Simple Conditions

There is a set of simple conditions to directly test values of specific questions and solutions. The most common is the "=" operator to check for a specific value.

%%prettify
{{{
// check for a certain choice
choice-question = choice

// note: for multiple-choice questions the operator evaluates to "true"
// if the compared choice is selected, regardless is any other choice is 
// additionally selected.
mc-question = choice1 AND mc-question = choice2

// check if the question is answered with a value of its normal range,
// or if the value is "unknown" (which means that the "unknown" choice 
// of the question is selected explicitly)
any-question = known
any-question = unknown

// check the state of a solution
solution = established
solution = suggested
solution = excluded

// check a question value to match a regular expression.
// the operator evaluates to "true" if the regular expression matches 
// the whole answer given to the question. This is usually used for
// text questions. Please note that the regular expression is quoted in "/"
text-question = /.*regex.*/
}}}
/%

For more details to regular expression, see e.g. [java documentation of regular expressions | http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html].


!! Numeric Conditions

Especially for numerical questions, there is a set of additional test operators.

%%prettify
{{{
// first we might use the original compare to equal, 
// both operators are the same
num-question = 10
num-question == 10

// there are also checks against limits of various types
num-question <= 10
num-question >= 10
num-question < 10
num-question > 10

// finally there is a special operator to check for intervals
num-question [10 20]
}}}
/%


!! Compound Conditions

The following operators can be used to build more complex expressions from simple rule conditions:

* __NOT__(condition): true, if the condition does not apply
* (condition1) __AND__ (condition2): true, only if both conditions apply at the same time
* (condition1) __OR__ (condition2): true, if at least one of the conditions do apply


!! Complex Formulas as Conditions
For more complex formulas on any values there is an additional plugin available. But be careful, this extension is non-LGPL-licensed for comercial use: [Extended Expressions: Conditions and actions | Doc Expressions]