WiringFiles

How to use XML or JSON files to specify the objects to create and their wiring.

Wallaroo Wiring Files

Wallaroo can load the description of your software from a configuration file, in XML or JSON format. You can use the file to specify the following:

• which objects instantiate
• the concrete class of each object
• set the object attributes
• the wiring between the objects
• shared libraries to load
  However, you can use more than one configuration file, or you can decide to specify only a part of your application with the configuration file.

Loading a wiring file

Once you have a Catalog object in your application, you can fill it by using the classes XmlConfiguration or JsonConfiguration.

To load a xml file:

Catalog catalog;
...
XmlConfiguration file( "wiring.xml" );
file.Fill( catalog );
...
catalog.CheckWiring(); // throws a WiringError exception if any collaborator is missing

To load a json file:

Catalog catalog;
...
JsonConfiguration file( "wiring.json" );
file.Fill( catalog );
...
catalog.CheckWiring(); // throws a WiringError exception if any collaborator is missing

If there are classes defined in shared libraries, you should load them by using the code:

// create file as XmlConfiguration or JsonConfiguration class
XmlConfiguration file( "myFile.xml" );
// or JsonConfiguration file( "myFile.json" );
...
file.LoadPlugins(); // load the shared libraries specified in configuration file

XML Wiring file syntax

The XML file is composed by three sections:

• the shared libraries to load (tag plugins)
• the object instances definition (tag parts)

• the objects wiring specification (tag wiring)

  <wallaroo></wallaroo>

  <plugins>
  ...
  </plugins>

  <parts>
  ...
  </parts>

  <wiring>
  ...
  </wiring>

Shared Libraries Section

If you want to load classes implemented in shared libraries you must write a section plugins where you specify every shared library to load:

<plugins>
  <shared>shared_lib_1</shared>
  <shared>shared_lib_2</shared>
</plugins>

Please note that the library name does not include the file extension: wallaroo add the os specific extension (.dll on windows, .so on linux).

Parts Section

For each object you want to be created, you must write a section part, where you specify the instance name (the id you will use to refer to this object) and the class of the object:

<part>

  <name>object_name</name>
  <class>class_name</class>

  <attribute> <!-- optional -->
    <name>attribute1_name</name>
    <value>attribute1_value</value>
  </attribute>
  <attribute> <!-- optional -->
    <name>attribute2_name</name>
    <value>attribute2_value</value>
  </attribute>
  ...

  <parameter1> <!-- optional -->
    <type>string</type>
    <value>parameter_value</value>
  </parameter1>
  <parameter2> <!-- optional -->
    <type>int</type>
    <value>3</value>
  </parameter2>

</part>

The parameter type currently supported are:

• char
• unsigned char
• int
• unsigned int
• long
• double
• bool
• string

Wiring Section

For each relation between the instances you created, you must write a section wire, where you specify the two object you want to link (source and destination) and the name of the collaborator in the source object:

<wire>
  <source>source_object</source>
  <dest>dest_object</dest>
  <collaborator>plut_in_source_object</collaborator>
</wire>

Example

This is an example of a XML wiring file:

<wallaroo>

  <plugins>
    <shared>car</shared>
    <shared>engine</shared>
  </plugins>

  <parts>

    <part>
      <name>ferrari_f430</name>
      <class>Car</class>
      <parameter1>
        <type>string</type>
        <value>red</value>
      </parameter1>
    </part>

    <part>
      <name>maserati_granturismo</name>
      <class>Car</class>
      <parameter1>
        <type>string</type>
        <value>black</value>
      </parameter1>
    </part>

    <part>
      <name>m139p</name>
      <class>Engine</class>
    </part>

    <part>
      <name>f136e</name>
      <class>Engine</class>
    </part>

  </parts>

  <wiring>

    <wire>
      <source>ferrari_f430</source>
      <dest>f136e</dest>
      <collaborator>mainEngine</collaborator>
    </wire>

    <wire>
      <source>maserati_granturismo</source>
      <dest>m139p</dest>
      <collaborator>mainEngine</collaborator>
    </wire>

  </wiring>

</wallaroo>

XML schema

At this page you can find the XML Schema of wallaroo xml wiring files: XmlSchema

JSON Wiring file syntax

The syntax of JSON file is equivalent to the XML one.

Follows an example of a JSON wiring file:

{
  "wallaroo":
  {

    "plugins":
    { 
      "shared": "car",
      "shared": "engine"
    },

    "parts":
    [
      {
        "name": "ferrari_f430",
        "class": "Car",
        "parameter1":
        {
          "type": "string",
          "value": "red"
        }
      },

      {
        "name": "maserati_granturismo",
        "class": "Car",
        "parameter1":
        {
          "type": "string",
          "value": "black"
        }
      },

      {
        "name": "m139p",
        "class": "Engine"
      },

      {
        "name": "f136e",
        "class": "Engine"
      }

    ],

    "wiring":
    [

      {
        "source": "ferrari_f430",
        "dest": "f136e",
        "collaborator": "mainEngine"
      },

      {
        "source": "maserati_granturismo",
        "dest": "m139p",
        "collaborator": "mainEngine"
      }

    ]
  }
}