Marshalling is the process of transforming the representation of an object to a data format suitable for storage or transmission. It is typically used when data (parameters) must be moved between different parts of a computer program or from one program to another. The opposite or reverse is referred to as Unmarshalling. In the GLU.Engine, all parameters received from any system must be unmarshalled into a format that the GLU.Engine can store (known as a GLU object) and later transform or use to pass on to subsequent receiving systems.

The process of converting the GLU parameter into a format that can be sent to a receiving system is called ‘marshalling’.

Unmarshalling and Marshalling can be used to change the names or formats of parameters between systems as well as restructure them into or out of Arrays.

An important convention to note is that when Marshalling GLU parameters from within your GLU.Engine to be delivered to any external system (be those ‘downstream’ systems that you send outbound Requests to or if you are returning a Response to the initial Inbound Request) you reference those variables with the format ${variableName} or if as per the example below when passing the variable into the Header (i.e. the Context Name / URL) you use the format ${header.variableName}. Conversely when you receive an incoming variable parameter and you are unmarshalling it since it does not yet exist in the GLU.Engine the variable format is simply {} i.e. without the $ sign.

Marshalling

This is when a GLU.Engine converts a GLU parameter object into Receiving System object.

In the example below, a Parameter named ‘routeDescription’ is being marshalled to the body of the outgoing request. The template for this request (as defined in the parent Request Manager) is:

Example: { “routeDescription” : “${routeDescriptionNewName}” }

Therefore, ‘routeDescription’ is being marshalled into ‘routeDescriptionNewName’, to be available in the request body. Note: The addition of the ‘NewName’ to the parameter name was solely for visualisation purposes, in practice it is common to name both the Parameter name and the marshalled one the same. It is also possible to marshal into the Header or the Query. See below:

Header

The Header refers to the ‘Context Name’ of the Request Manager. For example, to route to a variable after the /, you would need to use the .header syntax as follows:

/${header.headerStub}/echo

… and you would Marshal the ‘headerStub’ attribute to the Header as follows:

Query

The Query refers to the section following the ‘Context Name’ in the Request Manager. For example, to route to a variable after /stub/echo?appId=test , you would need to marshal it to the Query as below.

Exception: If you have a variable in the URL (dynamic URL), you need to marshal the value of the query to the header and insert the ?key in the URL, for example: /${header.variable}/something?key=${header.queryValueParameter}

Example: Keep The Value Null

When the GE receives a parameter with a null value

e.g { “nullParam1”: null } in the payload

The GLU.Engine will pass it as an EMPTY parameter because null is a GLU reserved word (Reserved Words). Therefore the option “Keep the value null” is to pass it as null i.e. the text ‘null’ remains as it is.

e.g response : “nullParam1”: null

Example: Don not pass empty or null values

On receiving a null value, this parameter is ignored and not marshalled.

Definition: ’empty’ – is when the parameter exists but there is no value e.g. “value1” : “”

Definition: ‘null’ – is when the parameter does not exist e.g. if expecting to see “value2” in a Response body but “value2” does not exist.

Order By

For arrays/lists, this is an expression by which to order the elements before proceeding to marshal the object

Unmarshalling

Multi-Dimensional Arrays

You can also unmarshal multi-dimensional arrays. Multidimensional Arrays can be defined in simple words as array of arrays. For example if you received an XML payload with a multi-dimensional array like this:

<soapenv:Body xmlns="http://schema.gluglobal.co.za/ssc/1.0/DeliveryTrip">
       <route xmlns="">
           <Zone>CPT</Zone>
           <ZoneId>910</ZoneId>
           <PlanReference>0917360</PlanReference>
           <Personnel>
               <Driver>
                   <IdNumber>0</IdNumber>
                   <Name>CTH DUMMY DRIVER</Name>
               </Driver>
               <CrewMembers>
                   <Crew>
                       <IdNumber>0</IdNumber>
                       <Name>CTH DUMMY CREW 1</Name>
                   </Crew>
                   <Crew>
                       <IdNumber>0</IdNumber>
                       <Name>CTH DUMMY CREW 2</Name>
                   </Crew>
               </CrewMembers>
           </Personnel>
           <RouteId>2200268213</RouteId>
           <Consignments>
               <Consignment>
                   <ConsignmentId>999</ConsignmentId>
                   <Dropoffs>
                       <Dropoff>
                           <Type>Delivery</Type>
                           <DropoffId>97625349782634</DropoffId>
                           <DueAt>2019-12-04T09:00:00</DueAt>
                           <SpecialInstructions>N/A</SpecialInstructions>
                           <Dimensions>
                               <Weight>0</Weight>
                               <Pieces>21</Pieces>
                               <Pallets>0</Pallets>
                               <Volume>
                                   <Length>0</Length>
                                   <Width>0</Width>
                                   <Height>0</Height>
                                   <Volume>.633213465</Volume>
                               </Volume>
                           </Dimensions>
                           ... etc.

To unmarshall the Volume attribute, in the ‘Volume’ Array, in your Object Collection Path you’d use the following:

Envelope.Body.route.Consignments.Consignment[].Dropoffs.Dropoff.Dimensions.Volume

Store As Object

For this response:

{ “result”: {“message”: {“prim_email_id”: [“20004: Duplicate email ID, Mobile Number exists”], “prim_id_no”: [“20006: Duplicate ID, ID Number exists.”], “prim_mob_no”: [“20002: Duplicate Mobile / Mobile Number exists”]}, “status”: “E”} }

Checking ‘Store As Object’ allows for storing of the entire “message” as a single object.

Note: Referencing this “message” requires the following format: [‘message’ without quotes]

{ “result”: { “message”: ${message}, “status”: “${status}” } }

FAQ’s