cligj 0.2.0

Example

Here’s an example of a command that writes out GeoJSON features as a collection or, optionally, a sequence of individual features. Since most software that reads and writes GeoJSON expects a text containing a single feature collection, that’s the default, and a LF-delimited sequence of texts containing one GeoJSON feature each is a feature that is turned on using the --sequence option. To write sequences of feature texts that conform to the JSON Text Sequences proposed standard (and might contain pretty-printed JSON) with the ASCII Record Separator (0x1e) as a delimiter, use the --rs option

import click
import cligj
import json

@click.command()
@cligj.sequence_opt
@cligj.use_rs_opt
def features(sequence, use_rs):
    features = [
        {'type': 'Feature', 'id': '1'}, {'type': 'Feature', 'id': '2'}]
    if sequence:
        for feature in features:
            if use_rs:
                click.echo(b'\x1e', nl=False)
            click.echo(json.dumps(feature))
    else:
        click.echo(json.dumps(
            {'type': 'FeatureCollection', 'features': features}))

On the command line it works like this.

$ features
{'type': 'FeatureCollection', 'features': [{'type': 'Feature', 'id': '1'}, {'type': 'Feature', 'id': '2'}]}

$ features --sequence
{'type': 'Feature', 'id': '1'}
{'type': 'Feature', 'id': '2'}

$ features --sequence --rs
^^{'type': 'Feature', 'id': '1'}
^^{'type': 'Feature', 'id': '2'}

In this example, ^^ represents 0x1e.

Plugins

cligj can also facilitate loading external click-based plugins via setuptools entry points. The cligj.plugins module contains a special group() decorator that behaves exactly like click.group() except that it offers the opportunity load plugins and attach them to the group as it is istantiated.

from pkg_resources import iter_entry_points

import cligj.plugins
import click

@cligj.plugins.group(plugins=iter_entry_points('module.entry_points'))
def cli():

    """A CLI application."""

    pass

@cli.command()
@click.argument('arg')
def printer(arg):

    """Print arg."""

    click.echo(arg)

@cli.group(plugins=iter_entry_points('other_module.more_plugins'))
def plugins():

    """A sub-group that contains plugins from a different module."""
    pass