<LESS_THAN/> "Less than" check in dynamic forms
The <LESS_THAN/> tag can be implemented in the value determination area of the rule definition (or for the definition of a precondition) and is used to compare two logical expressions. The result of the combined logical expression is a Boolean value, which is true when “Expression a” is less than “Expression b”:
<LESS_THAN>
Expression a
Expression b
</LESS_THAN>
The <LESS_THAN/> tag is used to check a property of the form against a comparison value.
To do this, a <PROPERTY/> tag is used to query a particular numeric property of the form element (such as the length of a value in an input component or the date from a CMS_INPUT_DATE type input component) within the <LESS_THAN/> tag.
The comparison value may be a fixed (numeric) default value or may refer to a numeric property of a (different) form element.
The following tags can be used to enter a fixed, defined default value:
- <NUMBER/>: used to enter a numeric comparison value within an expression of comparison.
- <DATE/>: used to enter a fixed, defined date within an expression of comparison.
Examples
1) Comparing a form property with a numeric default value
VALUE / NUMBER:
Compares the value of an input component (<PROPERTY/> tag) with a numeric default value (<NUMBER/> tag):
<LESS_THAN>
<PROPERTY source="rules_element" name="VALUE"/>
<NUMBER>2</NUMBER>
</LESS_THAN>
LENGTH / NUMBER:
Compares the length of the value of an input component (<PROPERTY/> tag) with a numeric default value (<NUMBER/> tag):
<LESS_THAN>
<PROPERTY source="st_text" name="LENGTH"/>
<NUMBER>2</NUMBER>
</LESS_THAN>
SIZE / NUMBER:
Compares the number of the entries of an FS_LIST type input component (<PROPERTY/> tag) with a numeric default value (<NUMBER/> tag):
<LESS_THAN>
<PROPERTY source="st_list" name="SIZE"/>
<NUMBER>2</NUMBER>
</LESS_THAN>
2) Comparing two form properties with each other
VALUE / VALUE:
Compares the numeric values from two input components with each other (using two <PROPERTY/> tags):
<LESS_THAN>
<PROPERTY source="st_value" name="VALUE"/>
<PROPERTY source="st_upperLimit" name="VALUE"/>
</LESS_THAN>
3) Comparing a date from an input component with a predefined date
VALUE / DATE:
Compares the value from a CMS_INPUT_DATE type input component (<PROPERTY/> tag) with a predefined date:
<LESS_THAN>
<PROPERTY source="st_date" name="VALUE"/>
<DATE>2012-12-01 12:00:00 +0100</DATE>
</LESS_THAN>