Bundle PropertiesΒΆ

A C++ Micro Services Bundle provides meta-data in the form of so-called properties about itself. Properties are key - value pairs where the key is of type std::string and the value of type Any. The following properties are always set by the C++ Micro Services library and cannot be altered by the bundle author:

  • bundle.id - The unique id of the bundle (type long)
  • bundle.location - The full path to the bundle’s shared library on the file system (type std::string)

Bundle authors must always add the following property to their bundle’s manifest.json file:

  • bundle.symbolic_name - The human readable name of the bundle (type std::string)

C++ Micro Services will not install any bundle which doesn’t contain a valid ‘bundle.symbolic_name’ property in its manifest.json file.

Bundle authors can add custom properties by providing a manifest.json file, embedded as a top-level resource into the bundle (see The Resource System). The root value of the JSON file must be a JSON object. An example manifest.json file would be:

{
  "bundle.symbolic_name" : "my bundle",
  "bundle.version" : "1.0.2",
  "bundle.description" : "This bundle provides an awesome service",
  "authors" : [ "John Doe", "Douglas Reynolds", "Daniel Cannady" ],
  "rating" : 5
}

All JSON member names of the root object will be available as property keys in the bundle containing the manifest.json file. The C++ Micro Services library specifies the following standard keys for re-use in manifest.json files:

  • bundle.version - The version of the bundle (type std::string). The version string must be a valid version identifier, as specified in the BundleVersion class.
  • bundle.vendor - The vendor name of the bundle (type std::string)
  • bundle.description - A description for the bundle (type std::string)

Note

Some of the properties mentioned above may also be accessed via dedicated methods in the Bundle class, e.g. GetSymbolicName() or GetVersion().

When parsing the manifest.json file, the JSON types are mapped to C++ types and stored in instances of the Any class. The mapping is as follows:

JSON C++ (Any)
object std::map
array std::vector
string std::string
number int or double
true bool
false bool
null Any()