ckanext-validationapi

This plugin belongs to a set of plugins for the _Datenregister_ – the non-public [CKAN] (https://ckan.org/) instance that is part of Berry’s open data portal [daten.berlin.de] (https://daten.berlin.de/).

‘ckanext-validationapì provides an API as a public wrapper around the internal Validator functions of CKAN.

The plugin implements the following CKAN interfaces:

— [IBlueprint] (http://docs.ckan.org/en/latest/extensions/plugin-interfaces.html#ckan.p…)
— [IConfigurer] (http://docs.ckan.org/en/latest/extensions/plugin-interfaces.html#ckan.p…)

# # Requirements

This plugin has been tested with CKAN 2.9 (which requires Python 3).

# # Using the API

All Validator functions that are available through ‘ckan.plugins.toolkit.get \ _validator’ can be used. The list of standard validators that CKAN offers is available at [https://docs.ckan.org/en/latest/extensions/validators.html] (https://docs.ckan.org/en/latest/extensions/validators.html). Plugins can add more validators by implementing the [IValidators] (https://docs.ckan.org/en/latest/extensions/plugin-interfaces.html#ckan…) interface.

The API is accessible via '$CKAN \ _URL/bees/validation’; currently its only method is validated. Only POST requests with content type ‘application/json’ are accepted.

The expected payload to 'validatè is a JSON object with two attributes:

— ‘Validator’: The name of the Validator as it would be passed to ‘ckan.plugins.toolkit.get \ _validator’.
— 'evaluates: The value we want to submit for validation.

HERE is an example:

THE FOLLOWING:
‘Validator’: ‘email \ _validator’,
‘value’: “jane.doe@company.com”
BULL.
If the Validator exists, ‘validationapì will call the Validator function with the provided value. The response will be a JSON object with these attributes:

— ‘Validator’: The name of the Validator as it would be passed to ‘ckan.plugins.toolkit.get \ _validator’.

— 'evaluates: The value that was submitted for validation.

— ‘success’: Whether or not 'valuis passed the validation.

— ‘result’: If successful, the output of the Validator. This will be the same as’ valué, but sometimes the Validator will perform some transformation as well.
— ‘messagea: If not successful, this will contain an error message as provided by the Validator.
HERE are some examples for communicating with the validation API via curl:

# # # Valid input, unchanged

curl – X POST \
—date ‘Validator’: ‘email \ _validator’, ‘value’: “jane.doe@company.com” “” \
—H "Content-Type: application/json "\
$CKAN \ _URL/bees/validation/validated

THE FOLLOWING:
‘Validator’: ‘email \ _validator’,
‘value’: “jane.doe@company.com”,
‘success’: true,
‘result’: “jane.doe@company.com”
BULL.
# # # Valid input, changed

curl – X POST \
—date ‘Validator’: ‘isodate’, ‘value’: “2004-10-10” – "\
—H "Content-Type: application/json "\
$CKAN \ _URL/bees/validation/validated

THE FOLLOWING:
‘Validator’: ‘isodate’,
‘value’: ‘2004-10-10’,
‘success’: true,
‘result’: ‘2004-10-10 00: 00: 00’
BULL.
# # # Invalid input

curl – X POST \
—date ‘Validator’: ‘isodate’, ‘value’: “2004-10-10x” – "\
—H "Content-Type: application/json "\
$CKAN \ _URL/bees/validation/validated

THE FOLLOWING:
‘message’: ‘Invalid: U’Datumsformat ung \ \ xfcltig. ',
‘Validator’: ‘isodate’,
‘value’: ‘2004-10-10x’,
‘success’: false
BULL.
# # # Errors

If possible, validationapi will catch errors and provide an error message in the same format as above, but with the HTTP Response Code 400 (Bad Request). Below are some examples:

# # # # Unknown Validator

curl – X POST \
—date ‘Validator’: ‘foolidator’, ‘value’: ‘Barbar’
—H "Content-Type: application/json "\
$CKAN \ _URL/bees/validation/validated

THE FOLLOWING:
‘Validator’: ‘foolidator’,
‘value’: ‘Barbar’,
‘success’: false,
‘Error’: THE FOLLOWING:
‘message’: ‘Bad Request – Validator \ ‘foolidator \’ does not exist’,
‘Code’: 7
BULL.
BULL.
# # # # Wrong Request Format

curl $CKAN \ _URL/bees/validation/validated

THE FOLLOWING:
‘Validator’: NULL,
‘value’: NULL,
‘success’: false,
‘Error’: THE FOLLOWING:
‘message’: ‘Bad Request – Validation API accepts only POST requests with content type ‘application/json’.’,
‘Code’: 1
BULL.
BULL.
# # # # Error Codes

The complete list of error codes is:

— Wrong HTTP method = 1
— Wrong content type = 2
— No request data found = 3
— Cannot decode JSON = 4
— Wrong type of JSON = 5
— Wrong JSON structure = 6
— Unknown Validator = 7
— Validator has unexpected number of arguments = 8
— Unexpected error = 20