Modify a variable

In all of the sections above, the transform option in the setVariable behavior is set to NONE, which leaves the value unchanged after assigning it. transform supports a large set of functions that in effect offers an embedded programming language. It allows you to:

• do basic arithmetic
• perform bitwise operations
• convert case
• locate and generate substrings
• make regular expression substitutions
• perform many conversions and encodings

See the setVariable behavior for comprehensive details.

To modify a value within any setVariable behavior, set its transform function along with any necessary dependencies. Each behavior can only transform its value once, so to transform a value more than once you need to form a chain of setVariable behaviors. Each subsequent behavior needs to reassign the transformed value back to itself, then perform an additional transformation.

This simple example modifies a LANG user variable, assigning it the value of the request's Accept-Language header. The initial behavior performs a SUBSTRING transform to limit the string to the initial two-letter code. The second behavior reassigns {{user.PMUSER_LANG}} back into LANG, then runs the UPPER transform to convert to uppercase.

{
    "name": "setVariable",
    "options": {
        "variableName": "PMUSER_LANG",
        "valueSource": "EXTRACT",
        "extractLocation": "CLIENT_REQUEST_HEADER",
        "headerName": "Accept-Language",
        "transform": "SUBSTRING",
        "startIndex": "1",
        "endIndex": "2"
    }
},
{
    "name": "setVariable",
    "options": {
        "variableName": "PMUSER_LANG",
        "valueSource": "EXPRESSION",
        "variableValue": "{{user.PMUSER_LANG}}",
        "transform": "UPPER"
    }
}

For more details on how to use variables within the Property Manager portal, see Variables.