Displays one of two possible outputs, depending on whether its input parameter is null.

Class Name




Required Input Parameters


The value to test. The value parameter is tested to determine if it is null, and the result of this test determines the name of the open parameter to render. For example, if the value parameter is null, then IsNull renders the value of its true open parameter.

Open Parameters


The value to render if the value parameter is null.


The value to render if the value parameter is not null.

Usage Notes

IsNull conditionally renders one of its open parameters based on the value of its value input parameter. If value is null, then the output parameter true is rendered. Otherwise, the output parameter false is rendered.


In this example, the ATG platform checks to see if MyProfile.email has a value, and if not, the ATG platform provides an input field for adding an email address and a button for saving it to the database.

<dsp:droplet name="IsNull">
  <dsp:param bean="MyProfile.email" name="value"/>
  <dsp:oparam name="true">
    <dsp:form action="address_book.jsp" method="POST">
      My email address:
      <dsp:input type="text" bean="MyProfileFormHandler.email"/>
      <dsp:input type="submit" bean="MyProfileFormHandler.update value="Update"/>