Watch these introductory videos to learn about using Jelly in the ServiceNow AI Platform.

Jelly Tags

if

• Description: The if tag is just what it looks like, an if tag. This is like an if statement in any programming language, but keep in mind that there is no elseif tag and no else tag. If you want to create that kind of structure, try the choose/when/otherwise syntax.
• Parameters: test - The condition to evaluate in order to determine if the block will execute.
• Example:

  <g:evaluate var="jvar_now_GR" object="true">
     var now_GR = new GlideRecord("incident");
     now_GR.addQuery("active", true);
     now_GR.query();
     now_GR;
  </g:evaluate>
   
  <j:if test="${!jvar_now_GR.hasNext()}">
     We did not find any active incidents.
  </j:if>
  <j:if test="${jvar_now_GR.next()}">
     We found ${jvar_now_GR.getRowCount()} active incidents.
  </j:if>
  

while

• Description: The while tag does a while loop.
• Parameters: test - The condition to evaluate in order to determine if the statement will loop through. This should be an expression enclosed in ${} or $[] that evaluates to true or false.
• Example:

  <g:evaluate var="jvar_now_GR" object="true">
     var now_GR = new GlideRecord("incident");
     now_GR.addQuery("active", true);
     now_GR.query();
     now_GR;
  </g:evaluate>
   
  <j:while test="${jvar_now_GR.next()}">
    <a href="incident.do?sys_id=${jvar_now_GR.getValue('sys_id')}">${jvar_now_GR.getValue('number')}</a>
  </j:while>

set

• Description: The set tag sets a variable.
• Parameters:
  • var - The variable to set. Often the system prefixes these variables with jvar_ for consistency.
  • value - The value to set var to. This is often an expression enclosed in ${} or $[].
  • defaultValue - If the value results to null or empty, this value is put into the var.
• Example:

  <j:set var="jvar_incident_number" value="${jvar_now_GR.getValue('number')}"/>

set_if

• Description: The set_if tag sets a variable based on a test. This tag is similar to the ternary operator in other programming languages (var = <test> ? <if_true> : <if_false>).
• Parameters:
  • var - The variable to set. Often the system prefixes these variables with jvar_ for consistency.
  • test - The condition to evaluate in order to determine if the statement will evaluate the true value or the false value. This should be an expression enclosed in ${} or $[] that evaluates to true or false.
  • true - The value to set the variable to if test evaluates to true. This parameter is optional, so if the field is blank, and if test evaluates to true, the variable is left blank.
  • false - The value to set the variable to if test evaluates to false. This parameter is optional, so if the field is blank, and if test evaluates to false, the variable will be left blank.

choose

• Description: The choose tag starts a choose block of code. This is similar to the if-elseif-else kind of syntax in most programming languages. With a choose tag, you can use when and otherwise tags to specify other blocks of code.
• Parameters: None
• Example:

  <j:choose>
     <j:when test="${jvar_now_GR.getRowCount() ${AMP}lt; 1}">We found multiple records!</j:when>
     <j:when test="${jvar_now_GR.next()}">We found record ${jvar_now_GR.getValue('number')}</j:when>
     <j:otherwise>Sorry, we could not find the record you specified.</j:otherwise>
  </j:choose>

when

• Description: The when tag is used within a choose block to indicate a condition. This tag is similar to an if or an elseif in that it specifies a condition, executes the inner content, and then implies a break at the end to leave the if-elseif construct.
• Parameters: test - The condition to evaluate in order to determine if the statement will loop through. This should be an expression enclosed in ${} or $[] that evaluates to true or false.
• Example:

  <j:choose>
     <j:when test="${jvar_now_GR.getRowCount() ${AMP}lt; 1}">We found multiple records!</j:when>
     <j:when test="${jvar_now_GR.next()}">We found record ${jvar_now_GR.getValue('number')}</j:when>
     <j:otherwise>Sorry, we could not find the record you specified.</j:otherwise>
  </j:choose>

otherwise

• Description: The otherwise tag is used within a choose/when/otherwise block, and is like the else or default case.
• Parameters: None
• Example:

  <j:choose>
     <j:when test="${jvar_now_GR.getRowCount() ${AMP}lt; 1}">We found multiple records!</j:when>
     <j:when test="${jvar_now_GR.next()}">We found record ${jvar_now_GR.getValue('number')}</j:when>
     <j:otherwise>Sorry, we could not find the record you specified.</j:otherwise>
  </j:choose>

Glide Tags

evaluate

• Description: The evaluate tag evaluates JavaScript code (server side), and makes variables visible to future code. Unlike other tags, the evaluate tag evaluates the content that is inside the tag as server side JavaScript.

  The context is the same as that of script includes in the system. Other script includes, global business rules, GlideRecord, GlideSystem, and Jelly variables (prefixed with jelly. if the parameter jelly="true" is set) are available.

• Parameters:
  • var - The name of the variable that will be set to the result of the script.
  • object - If set to true, the result of the expression is treated as an object instead of a primitive variable (string or integer variable values).
  • jelly - If set to true, allows Jelly context variables to be referenced in the script.
  • expression - This is an expression to be executed for the value to put in var. The expression can be either of two places. First, it can be an attribute on the evaluate tag itself. Otherwise, the content between the beginning tag and ending tag is the expression. The last line of the expression is the actual value passed into var.
• Example:

  <g:evaluate var="jvar_now_GR" object="true">
    var now_GR = new GlideRecord("incident");
    now_GR.addQuery("active", "true");
    now_GR.query();
    now_GR; // this is the variable put into the variable jvar_now_GR
  </g:evaluate>

  <g:evaluate var="jvar_now_GR" object="true" expression="
    var now_GR = new GlideRecord('incident');
    now_GR.addQuery('active', 'true');
    now_GR.query();
    now_GR; // this is the variable put into the variable jvar_now_GR" />

messages

• Description: The messages tag helps with translation. When gs.getMessage() is called anywhere on a page, there are two possible places where the translation is found. First, the page checks a local cache of translations. Second, the page makes an AJAX call to the server to find the translation. What g:messages does is allow pages to cache certain messages.
• Parameters: None
• Example:

  <g:messages>
    Yes
    No
    Cancel
  </g:messages>

breakpoint

• Description: When the breakpoint tag is called, it prints a list of all the variables in Jelly at the current moment, with their respective values. If a variable is specified, it prints the requested variable and its value. The output is placed in the system log.
• Parameters: var - (Optional) The variable to log the value for. If var is not specified, then all variables are dumped into the log.
• Example:

  <g:breakpoint />

  <g:breakpoint var="sysparm_view"/>

no_escape

• Description: The system, by default, uses escaped output as a security measure. Output placed inside of no_escape tags is not escaped before output. Be careful when using these tags, because if user input is displayed here it can open a security vulnerability on the page.
• Parameters: None
• Example (phase 1) – Disables automatic output escaping of all contained ${} expressions:

  <g:no_escape>
   ${jvar_raw_html_data}
  </g:no_escape>

• Example (phase 2) – Use NOESC to disable escaping for the specified string. This implies the expression must evaluate to a string.

  <g:no_escape>$[NOESC:jvar_expr]</g:no_escape>

  For information on phase 1 and phase 2 evaluation, refer to the Jelly introduction videos listed at the beginning of this section.

macro_invoke

• Description: The macro_invoke tag calls a UI macro that you have specified in the database. You may also call a UI macro by specifying it in the tag name. For example, if you had a UI macro named my_macro, you could call that macro with the tag <g:my_macro/>. For information, see UI macros.
• Parameters:
  • macro - The name of the UI macro to execute. If your tag name is g:macro_invoke, then the macro attribute specifies the name of the macro. If the tag name includes the name of the macro, then there is no need to include a macro attribute.
  • Other attributes - For each attribute you specify, a variable with that name will be available in the context of the UI macro, prefixed with jvar_.
• Example:

  <!-- Will invoke the contents of the UI macro named "sample_macro", which will have the variable jvar_message available within it-->
  <g:macro_invoke macro="sample_macro" message="This is a sample macro variable." />

  <!-- Will invoke the contents of the UI macro named "sample_macro", which will have the variable jvar_message available within it-->
  <g:sample_macro message="This is a sample macro variable." />

if_polaris

• Description: The if_polaris tag checks if Next Experience is enabled for the current page. It must include at least one of the child tags <g:then /> or g:else />.
• Parameters: None
• Example:

  <g:if_polaris>
      <g:then><g:inline template="polaris_nav"/></g:then>
      <g:else><g:inline template="classic_nav"/></g:else>
  </g:if_polaris>
  
  <g:if_polaris>
      <g:then><a href="…">Click here to see what’s new!</a></g:then>
  </g:if_polaris>
  
  <g:if_polaris>
      <g:else>Core UI only code here!</g:else>
  </g:if_polaris>
  

then

• Description: The then tag is used within an if_polaris block to set the page content when Next Experience is enabled.
• Parameters: None
• Example:

  <g:if_polaris>
      <g:then><g:inline template="polaris_nav"/></g:then>
      <g:else><g:inline template="classic_nav"/></g:else>
  </g:if_polaris>
  
  <g:if_polaris>
      <g:then><a href="…">Click here to see what’s new!</a></g:then>
  </g:if_polaris>
  
  <g:if_polaris>
      <g:else>Core UI only code here!</g:else>
  </g:if_polaris>
  

else

• Description: The else tag is used within an if_polaris block to set the page content when Next Experience isn't enabled.
• Parameters: None
• Example:

  <g:if_polaris>
      <g:then><g:inline template="polaris_nav"/></g:then>
      <g:else><g:inline template="classic_nav"/></g:else>
  </g:if_polaris>
  
  <g:if_polaris>
      <g:then><a href="…">Click here to see what’s new!</a></g:then>
  </g:if_polaris>
  
  <g:if_polaris>
      <g:else>Core UI only code here!</g:else>
  </g:if_polaris>