IML is a mustache-like markup language with support for evaluating complex expressions in javascript-like syntax.
Expressions are written between mustaches: {{body.data}}.
+, -, *, /, %
== (or ===, same thing), <, <=, >, >=, !=
you can use ' or " to put strings inside IML expressions:
{{'Hello, ' + item.name}}
{{"Hello, " + item.name}}
You can create conditionals with if and ifempty functions.
{{if(body.id > 100, body.user, false)}}
{{ifempty(body.username, body.user)}}
ifempty function returns second argument when first argument is either
not defined, null or empty string. Otherwise it returns first argument.
You can use normal JavaScript . (dot) notation to retrieve properties
of collections, such as parameters: {{parameters.input.data}}.
If the property name contains spaces or starts with a non-alphabetic
character or contains non-alphanumeric characters (except underscore
_), you can use ` (back ticks) to retrieve such properties:
{{headers.`X-HOOK-TYPE`}} or {{parameters.`First Name`}}.
You can use normal JavaScript [] brackets notation to retrieve a
specific element from an array: {{body.data[2].prop}}. Unlike
JavaScript, IML uses 1 to access the first item in an array.
You can also use -1 to access the last element of an array, like so:
body.data[-1].prop.
Tip: If you need to retrieve a property of an object, and the
property name is contained in a variable, or computed, the dot .
notation will not work. For this you can use the get function, where
the first argument of the function is the object you wish to retrieve
the property from, and the second argument is the property name, or a
variable containing a property name, or an expression that resolves to
a property name: get(body.data, 'some property'),
get(body, parameters.fieldName),
get(body.data, if(body.xml == true, 'xml', 'json'))
List of built-in IML functions is available here.
See also Custom IML Functions