Class ExpressionCustomizer


  • public class ExpressionCustomizer
    extends Object
    A mechanic to allow a certain customization for ExpressionResolver.

    The customization is only scoped to the current request, not a global one. The resource type implementation needs to use this class explicitly to make the customization available in the request scope going forward.

    For example, the resource type implementation of CQ Dialog (/apps/my/dialog) wants to register cqDesign variable so that it can be used in EL expression:

     
     Design design = getDesign();
     ExpressionCustomizer customizer = ExpressionCustomizer.from(request);
     customizer.setVariable("cqDesign", design);
     
     

    Then in the content structure, the content author can use cqDesign variable in the property that accepts EL:

     
     + /apps/content/my/dialog
       - sling:resourceType = "my/dialog"
       + field1
         - sling:resourceType = "my/textfield"
         - value = "${cqDesign.id}"
     
     
    • Constructor Detail

      • ExpressionCustomizer

        public ExpressionCustomizer()
    • Method Detail

      • from

        @Nonnull
        public static ExpressionCustomizer from​(@Nonnull
                                                ServletRequest request)
        Returns the instance from the given request.
        Parameters:
        request - the current request acting as the scope of the customization
        Returns:
        the instance of the customizer
      • getVariable

        @CheckForNull
        public Object getVariable​(@Nonnull
                                  String name)
        Returns the value of the variable with the given name.
        Parameters:
        name - the name of the variable
        Returns:
        the value of the variable, or null if there is no variable with that name
      • setVariable

        public void setVariable​(@Nonnull
                                String name,
                                @Nonnull
                                Object value)
        Creates a variable with the given name and value.

        Setting an existing variable with the same name will overwrite its value.

        Parameters:
        name - the name of the variable
        value - the value of the variable
      • hasVariable

        public boolean hasVariable​(@Nonnull
                                   String name)
        Returns true if there is a variable with the given name; false otherwise.
        Parameters:
        name - the name of the variable
        Returns:
        true if there is a variable with the given name; false otherwise