Json
The JSON Extension provides the
JsonOutputHandler
for output rendering in pure JSON, as well as the JsonConfigHandler
that allows applications to use JSON configuration files as a drop-in replacement of the default ConfigParserConfigHandler
.Documentation References:
API References:
- No external dependencies
This extension does not rely on any application level configuration settings or meta options.
In some edge cases users have wanted to use an alternative json module for performance reasons, in particular UltraJson. It is possible to override the backend
json
library module to use, such as ujson
or another drop-in replacement library. The recommended solution would be to override the JsonOutputHandler.Meta.json_module
:Example: Using an Alternative Json Module
from cement import App, init_defaults
META = init_defaults('output.json', 'config.json')
META['output.json']['json_module'] = 'ujson'
META['config.json']['json_module'] = 'ujson'
class MyApp(App):
class Meta:
label = 'myapp'
extensions = ['json']
meta_defaults = META
Example: Using Json Config Handler
myapp.py
from cement import App
class MyApp(App):
class Meta:
label = 'myapp'
extensions = ['json']
config_handler = 'json'
config_file_suffix = '.json'
~/.myapp.json
{
"myapp": {
"foo": "bar"
}
}
In general, you likely would not set
output_handler
to json
, but rather another type of output handler that displays readable output to the end-user (ex: Mustache, Jinja2, or Tabulate). However, Cement supports overriding handlers via command line options if the Handler.Meta.overridable
option is set. For example, -o json
will trigger the framework to use the json
output handler, overriding the default set in App.Meta.output_handler
.Example: Using Json Output Handler
cli
myapp.py
from cement import App, init_defaults
META = init_defaults('output.json')
META['output.json']['overridable'] = True
class MyApp(App):
class Meta:
label = 'myapp'
extensions = ['json', 'mustache']
meta_defaults = META
output_handler = 'mustache'
template_dir = './templates'
with MyApp() as app:
app.run()
data = {'foo': 'bar'}
app.render(data, 'example.m')
templates/example.m
Foo: {{ foo }}
$ python myapp.py
Foo: bar
$ python myapp.py -o json
{"foo": "bar"}
Last modified 1yr ago