XAPPT - extensible application toolkit

XAPPT (pronounced like "zapped") is a toolkit that makes it easy to create custom command line tools and invoke them from a uniform interface.

XAPPT requires Python 3.7 or higher.

To get started just create a subclass of xappt.models.plugin.Plugin, and make sure it's loadable by invoking your package, or a plugins submodule of your package.

The name of your module should have the prefix "xappt". This allows automatic plugin discovery by scanning sys.path, and scanning paths defined on the environment variable XAPPT_PLUGIN_PATH.

Getting started

If xappt is installed to the system Python interpreter, it should be available on the command line just by running the xappt command.

If everything is installed properly you should get output that looks like this:

$ xappt
usage: xappt [-h] [--version] {} ...

positional arguments:
  {}  Sub command help

optional arguments:
  -h, --help   show this help message and exit
  --version    Display the version number

Let's walk through creating a custom plugin. I'll be doing this on Linux, but the process is pretty similar on other systems.

First, make sure that xappt is installed:

$ pip3 install xappt

Next, let's make sure that xappt is available on the command line:

$ xappt --version
xappt 0.0.3-4735e57

Now lets make a new plugin:

$ cd ~
$ mkdir -p temp/xappt_plugin
$ cd temp/xappt_plugin
$ touch __init__.py

We're created a folder named "temp", and inside that a folder named "xappt_plugin".

The reason for the two folders is so that we can add "temp" to XAPPT_PLUGIN_PATH, so that the "xappt_plugin" folder can be found inside it. We'll get to that momentarily.

Then we create a new file in "xappt_plugin" named __init__.py.

Now in __init__.py add the following code:

import xappt


@xappt.register_plugin
class MyPlugin(xappt.BaseTool):
    arg1 = xappt.ParamString(required=True)
    arg2 = xappt.ParamString(required=True)
    arg3 = xappt.ParamString(required=True)

    @classmethod
    def help(cls) -> str:
        return str("A simple command that will just echo the passed in arguments")

    def execute(self, interface: xappt.BaseInterface, **kwargs) -> int:
        print(self.arg1.value)
        print(self.arg2.value)
        print(self.arg3.value)
        return 0

Finally, we have to add that "temp" folder to an environment variable to make our plugin discoverable, and then invoke xappt.

On Linux this would look something like this:

$ export XAPPT_PLUGIN_PATH=~/temp
$ xappt

On Windows it would look like this:

set XAPPT_PLUGIN_PATH=C:\path\to\temp
xappt

The output should now look like this:

usage: xappt [-h] [--version] {myplugin} ...

positional arguments:
  {myplugin}            Sub command help
    myplugin            A simple command that will just echo the passed in arguments

optional arguments:
  -h, --help            show this help message and exit
  --version             Display the version number

And when running xappt myplugin:

$ xappt myplugin
usage: main.py example [-h] --arg1 ARG1 --arg2 ARG2 --arg3 ARG3
xappt myplugin: error: the following arguments are required: --arg1, --arg2, --arg3

So let's pass in some arguments:

$ xappt myplugin --arg1 123 --arg2 abc --arg3 xyz
123
abc
xyz

For more complicated plugins you can have a structure like this:

/xappt_plugin
    /plugins
        __init__.py
        myplugin.py
    __init__.py

In this case myplugin.py would contain the MyPlugin class. And xappt_plugin/plugins/__init__.py might look like this:

from .myplugin import MyPlugin

And that's it. Now feel free to make execute do something actually useful.

Examples

Xappt ships with a few example plugins that you can dissect. To load these plugins set an environment variable named XAPPT_LOAD_EXAMPLE_TOOLS to "1" before loading Xappt.

$ export XAPPT_LOAD_EXAMPLE_TOOLS=1

These examples can be found in xappt.plugins.tools.examples.