Condition Tag: Create Simpler References to Condition Logic

The <condition> element enables you to declare a named condition. Instead of rewriting condition logic across your entire survey, you can use the <condition> element to write it once and then refer to the condition using the element's label.

For example, in the code below, specifying condition.male is the same as specifying Q1.r1. This means that the "Male_Section" <block> will only be shown to those who are condition.male or Q1.r1.

<radio label="Q1" optional="0">
  <title>Are you...</title>
  <row label="r1">Male</row>
  <row label="r2">Female</row>
</radio>
<suspend/>

<condition label="male" cond="Q1.r1">Is Male</condition>
<condition label="female" cond="Q1.r2">Is Female</condition>

<block label="Male_Section" cond="condition.male">
    ...
    ...
</block>

<block label="Female_Section" cond="condition.female">
    ...
    ...
</block>

The <condition> element may be added anywhere within the survey's XML, but it is best practice to write them at the top of the file (just below the <samplesources> element).

Tip: Click here to learn more about creating sections with the Block tag. 

1:  Attributes

There are two attributes available for <condition> elements.

Attribute	Type	Description
cond	string	This is the condition logic. This should be a Python expression that will evaluate to True or False.
label	string	This is the condition's name. This is what you will use to refer to the condition's logic.

If desired, you can also add builder:warning="unsupported" to flag an element as unsupported and prevent a project from launching.

1.1:  cond - Setting the Condition

The cond attribute is the logic for the <condition> element. Instead of rewriting the same condition logic across the survey, you can specify the logic inside the cond attribute of a <condition> element and refer to it instead.

For example, instead of writing the condition Q2.ival ge 18 for both questions Q3 and Q4, you can declare a <condition> element named "isAdult" and write the condition inside of the cond attribute:

<number label="Q2" size="3" verify="range(1, 125)">
  <title>Please enter your age below:</title>
</number>
<suspend/>

<condition label="isAdult" cond="Q2.ival ge 18">Age is 18 or older</condition>

<radio label="Q3" optional="0" cond="condition.isAdult">
  <title>Have you ever been to a casino before?</title>
  <row label="r1">Yes</row>
  <row label="r2">No</row>
</radio>

<radio label="Q4" optiona="0" cond="condition.isAdult">
  <title>Have you ever been to a bar before?</title>
  <row label="r1">Yes</row>
  <row label="r2">No</row>
</radio>

With this <condition> element in place, you can refer to the logic using the condition.label syntax (e.g., condition.isAdult) and show both questions Q3 and Q4 appropriately.

1.2:  label - Specifying the Condition's Name

The label attribute is the <condition> element's name. It is best to set this attribute to a human-readable string that can be easily remembered and typed out.

For example:

<condition label="maleTV" cond="Q1.r1 and Q2.r3 and (Q3.r1 or Q3.r2 or Q3.r3)">Males who frequently watch TV</condition>

<condition label="maleGamers" cond="Q1.r1 and (Q2.r4 or Q2.r5)">Males who game via console or PC</condition>

<condition label="femaleTV" cond="Q1.r2 and Q2.r3 and (Q3.r1 or Q3.r2 or Q3.r3)">Females who frequently watch TV</condition>

<condition label="femaleGamers" cond="Q1.r2 and (Q2.r4 or Q2.r5)">Females who game via console or PC</condition>

2:  Viewing Conditions Table in the Report

A table named "Conditions" gets created automatically in the report containing a row for every <condition> element in a survey. Run the "Total" report in Crosstabs to access the conditions table.

Note:  This information is also available in the data downloads. Since this creates a new variable, moving, deleting or adding new <condition> elements would require an hmerge.