isnull

This rule checks the value of the specified field and returns true if the field value is null. The syntax for isnull is:

<isnull fieldName="name"/>

The parameter for isnull is:

• fieldName – The qualified field name or assigned variable for the field to check for null values.

Example 18 Sample isnull Rule

The following sample checks the first name field for null values. If any first names are null, the record is rejected and written to the bad data file. Otherwise, the field is returned as good data.

<rule>
  <if>
    <condition>
      <isnull fieldName="Person.FirstName"/>
    </condition>
    <then>
      <reject fieldName="Person.FirstName"/>
    </then>
    <else>
      <return fieldName="Person.LastName"/>
    </else>
  </if>
</rule>