Message request filter
This filter gets (potentially) invoked for every request packet of type MSG.
JSON expression : optional - a JSON expression. If specified, the filter will be invoked only if the body or at least one of the sections in the packet matches the expression.
log : the log object
context : contains all the variables you'll commonly use:
packet : the packet being filtered, which will always be an MSG packet
matchPath : a list of lists of strings, set if the JSON expression parameter is specified. This will contain, for each expression, the path into the first document that satisfied the expression.
matchSection : if the JSON expression parameter is specified, which section of the message was the first match
result : the result object, used to cancel the current packet if desired
filterContext: an object containing variables attached to this filter. Any changes to this object will be visible to all invocations of this filter.
connectionContext: an object containing variables attached to the connection. Any changes to this object will be visible to all filters defined on this connection.
Let's assume that you want to intercept a message that looks like this:
You can create a message response filter with the following JSON expression:
In this example, the value for the matchPath variable would be set to: [[update, customers], [updates, 0, balance, $eq]]