Wednesday, February 5, 2014

Mediators : How to use WSO2 Script Mediator to do date validations.

The WSO2 ESB provides a whole suite of mediators with which you can do all sorts of request/response/variable manipulations and validations.

This article will be the first of a series of posts to follow on various mediators.

For the sake of this article, we will be using javascript inside the script mediator to do a simple XML DATE validation.



The above code would convert a XML DATE which is of the following format "YYYY-MM-DDTHH:MM:SS" (E.g. : 2010-08-01T00:00:00) to a regular Javascript date, add 5 years to the same and see if current date is greater than said value. Accordingly it would assign a variable to synapse messagecontext, which you may access later as you would any synapse property. (Please refer [1] for additional methods, you may call on the Synapse MessageContext from the script mediator.)

You may use a filter/switch mediator later on in your flow to execute appropriate logic based on the "result" variable you assigned from inside the script.

The script also has logic on how we can do xpath extractions from javascript itself.

var endDay = mc.getPayloadXML()..*::Date.toString(); 

This will seek out an xml elements like <Date>2010-08-01T00:00:00</Date> or JSON elements like
{"Date" : "2010-08-01T00:00:00"}. The principal to remember here is that WSO2 ESB converts JSON requests/responses to XML format in it the run time. So with the above line of code, you may access both XML and JSON payloads, like you would any XPATH.

Note that you may either embed the script inline (like above) or either store it in the registry as a file and point like

<script language="js" key="gov:trunk/scripts/test.js" function="validateDate"/>

References :

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