Fluid Syntax: Conditions & Booleans

Boolean conditions

Boolean conditions are expressions that evaluate to true or false.

Boolean conditions can be used as ViewHelper arguments, whenever the datatype boolean is given, e.g. in the condition argument of the <f:if> ViewHelper.

1. The expression can be a variable which is evaluated as follows:

   • number: evaluates to true, if is not 0.
   • array: evaluates to true if it contains at least one element

2. The expression can be a statement consisting of: term1 operator term2, for example {variable} > 3

   • The operator can be one of >, >=, <, <=, ==, ===, !=, !== or %,
3. The previous expressions can be combined with || (or) or && (and).

Examples:

<f:if condition="{myObject}">
  ...
</f:if>

<f:if condition="{myNumber} > 3 || {otherNumber} || {somethingElse}">
   <f:then>
      ...
   </f:then>
   <f:else>
      ...
   </f:else>
</f:if>

<my:custom showLabel="{myString} === 'something'">
  ...
</my:custom>

Example using the inline notation:

<div class="{f:if(condition: blog.posts, then: 'blogPostsAvailable', else: 'noPosts')}">
  ...
</div>

Boolean literals

You can use the boolean literals {true} and {false} in ViewHelper calls. This works both in tag and inline syntax:

<f:render section="MySection" optional="{true}" />

{f:render(section: 'MySection', optional: true)}

If a ViewHelper argument is defined as boolean, it is also possible to provide values of different types, which will then be converted to boolean implicitly:

<f:render section="MySection" optional="1" />

This can be used to remain compatible to Fluid 2, which didn't support boolean literals in all cases.