Table of Contents

• Table of Contents
• UVengine
  • Official website
  • Description
  • How to use it
    • Video demo
  • Using the library
    • Requirements
    • Download and install
    • Usage
    • Execution
      • Executing the Case Studies
  • References and third-party software

UVengine

Universal Variability resolution engine for UVL models and text-based artifacts with Jinja templates.

Official website

• UVengine

Description

UVengine is a variability resolution engine for UVL models and text-based artifacts with Jinja templates.

Its main features are:

• A variability resolution engine for UVL models.
• Support all language level extensions of UVL.
• Feature traceability between UVL models and implementation artifacts.
• Language independence for any text-based artifacts using Jinja templates.
• Composition and annotation-based mechanisms to implement variability at different degrees of granularity.
• Easy integration with existing tools of the UVL ecosystem such as UVLS and flamapy.

How to use it

The tool is currently deployed and available online in the following link so that you don't need to install any stuff:

https://uvengine.github.io/

The main use case of the tool is uploading the files and it automatically resolves the variability.

• Inputs:
  • The feature model (.uvl).
  • A configuration of the feature model (.json).
  • The templates artifacts (.jinja)
  • A mapping model (optional) to relate the features in the feature model within the variation points in the artifacts.
• Outputs:
  • The artifacts with their variability resolved.

Video demo

Using the library

In case you want to use UVengine programatically as a library or using CLI.

Requirements

• Python 3.9+
• Flamapy
• Jinja

Download and install

1. Install Python 3.9+

2. Clone this repository and enter into the main directory:

   git clone https://github.com/UVengine/uvengine

   cd uvengine

3. Create a virtual environment:

   python -m venv env

4. Activate the environment:

   In Linux: source env/bin/activate

   In Windows: .\env\Scripts\Activate

5. Install the dependencies:

   pip install -r requirements.txt

Usage

The derivation_engine.py script illustrate how to use UVengine programatically.

Basically:

# Import the UVengine 
from uvengine import UVEngine

# Instantiate the engine
uvengine = UVEngine(feature_model_path=<<path_to_your_feature_model>>,
                    configs_path=<<list_of_paths_to_your_configs_files>>,
                    templates_paths=<<list_of_paths_to_your_template_files>>,
                    mapping_model_filepath=<<path_to_your_mapping_model_files>>)
# Resolve the variability                    
resolved_templates = uvengine.resolve_variability()

# Save the resolved templates to file and print the content to the standard output
for template_path, content in resolved_templates.items():
    # Rename output file for avoiding overriding original templates and remove .jinja extension
    output_file = pathlib.Path(template_path).with_name(pathlib.Path(template_path).stem + '_resolved' + ''.join(pathlib.Path(template_path).suffixes).replace('.jinja', ''))  
    with open(output_file, 'w', encoding='utf-8') as file:
      file.write(content)
    print(content)

Execution

The derivation_engine.py script is also the entry point interface to resolve the variability from the given inputs.

To resolve the variability over any input, execute:

python derivation_engine.py -fm FEATURE_MODEL -c CONFIGS [CONFIGS ...] -t TEMPLATES [TEMPLATES ...] [-m MAPPING_FILE]

where:

-fm FEATURE_MODEL: Feature model in UVL (.uvl).

-c CONFIGS [CONFIGS ...]: Configuration files (.json) or directy with configurations (in case of a single configuration split in multiple files).

-t TEMPLATES [TEMPLATES ...]: Template files (.jinja) or directory with templates over which the variability is resolved.

[-m MAPPING_FILE]: Optional file with the mapping between the features in the feature model and the variation points and variants in the templates (.csv).

Example:

python derivation_engine.py -fm case_studies/icecream/feature_model/icecream.uvl -c case_studies/icecream/configurations/cone.json -t case_studies/icecream/templates/main.txt.jinja -m case_studies/icecream/mapping_model/icecream.csv

As result, the final product (i.e., the templates with the variability resolved) are generated in the same template folder provided with the suffixes _resolved.

Executing the Case Studies

To facilitate the execution of the different case studies, we have prepared a Python script for each case study:

• Ice cream: python cs1_icecream.py

• Docker: python cs2_docker.py

References and third-party software

• Flama
• Jinja