WaffleConf

The WaffleConf object initializes the application state for performing configuration udpates.

Notice that every time there is a change in the values for the variables defined in WAFFLE_CONFS, the database values and those in app.config will be refreshed.

Initialization

WaffleConf(app=None, configstore=None)

Calls the init_app() method with the given app and configstore parameters.

Parameters

• app: Flask application instance
• configstore: WaffleStore instance

Methods

init_app(app, configstore)

Initializes the state object and registers the waffleconf blueprint for accessing the default template.

_WaffleState

This is the object stored in app.extensions['waffleconf'], and is in charge of performing the parsing and updating of the configuration variables.

In addition, it stores the form template to use in order to display/update the configuration variables. If the WAFFLE_TEMPLATE variable is not set in the configuration, it will default to waffleconf/waffle_form.html.

Initialization

_WaffleState(app, configstore)

Initializes the object. Once initialized, it parses the configuration in the database, updating the keys in app.config where needed.

Methods

_listen()

Method that initializes the listener when WAFFLE_MULTIPROC is set to True. The listener awaits messages from Redis, checks the timestamp of the message and if it is greater than the one stored, updates the application configuration and the timestamp.

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_parse_conf(configs)

Parse the configuration in the database and store the values in app.config.

Parameters

• configs: dict obtained from app.config['WAFFLE_CONFS'] which contains information on each variable.

Returns

• dict: parsed configuration values with their proper data types using the configuration variable id as key.

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update_conf(configs)

Update configuration variables in the database. This also updates the application configuration.

When WAFFLE_MULTIPROC is set to True, this will also notify the update to the other application instances.

Parameters

• configs: dict of configuration variables and their values

The dict has the following structure:

{
    'MY_CONFIG_VAR'  : 'CONFIG_VAL',
    'MY_CONFIG_VAR1' : 'CONFIG_VAL1'
}

Ideally, this dict is obtained from a form.