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.

Features¶

The list fo features is plit 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
Structure through structs, enums, flags
Interface API with properties, operations and signals
Annotations using YAML syntax
Documentable IDL

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

python3

and then

import qface

Custom Generator¶

For your own generator you need several ingredients. A QFace interface file (here called “sample.qface”), a small script which loads and parses the document (generator.py) and one or more template files, used by the script to generate the resulting code.

The QFace document could look like this

// sample.qface
module org.example 1.0

interface Echo {
    string echo(string msg);
}

Your generator can now parse the documents and call the templates

// generator.py
from qface.generator import FileSystem, Generator

system = FileSystem.parse('sample.qface')
generator = Generator('./templates')
for module in system.modules:
    ctx = { 'module' : module }
    generator.write('{{module}}.txt', 'module.tpl', ctx)

The final piece is the template to parameterize the output in this case called “module.tpl”

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

Now you can simple call your script

python3 generator.py

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

Bundled Generators¶

QFace has some generators which are bundled with the QFace library. They live in their own repositories. These generators are documented in their respective repositories.