Repository is hosted at https://github.com/pelagicore/qface

QFace is a flexible API generator inspired by the Qt API idioms. It uses a common IDL format (called QFace interface document) to define an API. QFace is optimized to write a custom generator based on the common IDL format.

Several code generators for common use cases have already been implemented. These can be used as is or can be used as a base for a custom generator.


The list fo features is split between features which are based on the chosen IDL and features which are provided by the generator itself.

IDL Features

  • Common modern IDL
  • Scalable through modules
  • Structured data through structs, enums, flags
  • Interface API with properties, operations and signals
  • Annotations using YAML syntax
  • Fully documentable

Generator Features

  • Easy to install using python package manager
  • Designed to be extended
  • Well defined domain objects
  • Template based code generator
  • Simple rule based code builder
  • Well documented

Quick Start

QFace is a generator framework and is bundled with several reference code generators.

To install qface you need to have python3 installed and typically also pip3

pip3 install qface

This installs the python qface library onto your system.

You can verify that you have qface installed with

qface --help

Custom Generator

To write a custom generator it is normally enough to write a generator rules and the used templates. We use a QFace interface file (here called “sample.qface”) as an example.

The QFace document could look like this

// interfaces/sample.qface
module org.example 1.0

interface Echo {
    string echo(string msg);

We need now to write our templates for the code generation. In our example we would simple print out for each module the interfaces and it’s operations.

{# templates/module.tpl #}
{% for interface in module.interfaces %}
{% endfor %}

This will write for each interface in the module the text <module>.<interface>. The rules file will define what shall be generated and where.

# qface-rules.yaml

      - {{module}}.csv: module.tpl

The first entry defined a scope (e.g. project). Then for each module we geenrated documents. We use the module.tpl document from the templates folder and generate a CSV document based on the module name.

Now you can simple call your rules document

qface --rules qface-rules.yaml --target output interfaces

And a “org.example.csv” file named after the module should be generated.

See Also


QFace has several generator maintained by the qface team. They are maintained and documented in their own repositories.