PIP & Dependencies

The plugin system includes a built-in package manager that can automatically download and install dependencies from PyPI.

Declaring Dependencies

To use external libraries, you need to list them in your plugin's metadata using the __requirements__ variable. This should be a list of strings following the standard PEP 508 requirement format.

__id__ = "inline_calculator"
__name__ = "Inline Calculator"
__requirements__ = ["mpmath", "tinydb"]
 
from base_plugin import BasePlugin, HookResult, HookStrategy
from mpmath import mp
from tinydb import TinyDB
 
class CalculatorPlugin(BasePlugin):
    ...

When a user installs your plugin, exteraGram will automatically download these libraries and their dependencies.

How it Works

1. Resolution: The system fetches package metadata from PyPI to find a version that satisfies your constraints.
2. Pure-Python Only: It only downloads "pure-Python" wheels (files ending in -none-any.whl).
3. Isolation: Libraries are installed in a shared libs directory. If multiple plugins require the same version of a library, it is only downloaded once.
4. Automatic Cleanup: When you uninstall a plugin, any dependencies that are no longer needed by any other plugin are automatically removed.

Limitations

The built-in package manager has several important limitations compared to a full pip installation:

1. No Binary Extensions

The most significant limitation. Many popular Python libraries (like numpy, pandas, scipy, cryptography, or opencv) contain C/C++ extensions. These cannot be installed because they must be compiled for the specific Android architecture and linked against the application's Python runtime.

• Allowed: Packages that say "Universal" or "none-any" in their wheel filename.
• Forbidden: Packages that require a specific platform (e.g., manylinux, macosx, win_amd64) or have compiled components.

2. Dependency Conflicts

Unlike a virtual environment, all plugins share the same set of installed libraries.

• If Plugin A requires requests==2.25.1 and Plugin B requires requests==2.31.0, a conflict occurs.
• The system will attempt to use a version that satisfies both. If no such version is currently active or available, the installation of the second plugin will fail.

3. Network Access

Installation requires an active internet connection to reach pypi.org and download files.

4. Limited Marker Support

The system supports basic environment markers (like python_version, sys_platform), but complex markers or those referring to extra might not work as expected.

Pre-installed Libraries

Some libraries are pre-installed in the application for performance and stability. You don't need to list them in __requirements__, but doing so is harmless.

Check the Available Libraries page for the full list.

Troubleshooting

If a plugin fails to install due to a dependency error:

• "No pure-Python wheel found": The library you are trying to use contains compiled code. You cannot use this library unless it is manually added to the core application.
• "Dependency conflict": Another installed plugin is using an incompatible version of the same library.
• "Package not found": Check the spelling of the package name or its availability on PyPI.