This CKAN Extension demonstrates some common patterns for customising a CKAN instance. | This CKAN Extension demonstrates some common patterns for customising a CKAN instance. |
It comprises: | It comprises: |
* A CKAN Extension "plugin" at ``ckanext/example/plugin.py`` which, when | * A CKAN Extension "plugin" at ``ckanext/example/plugin.py`` which, when |
loaded, overrides various settings in the core ``ini``-file to provide: | loaded, overrides various settings in the core ``ini``-file to provide: |
* A path to local customisations of the core templates and stylesheets | * A path to local customisations of the core templates and stylesheets |
* A "stream filter" that replaces arbitrary strings in rendered templates | * A "stream filter" that replaces arbitrary strings in rendered templates |
* A "route" to override and extend the default behaviour of a core CKAN page | * A "route" to override and extend the default behaviour of a core CKAN page |
* A custom Pylons controller for overriding some core CKAN behaviour | * A custom Pylons controller for overriding some core CKAN behaviour |
* A custom Package edit form | * A custom Package edit form |
* A custom Group edit form | * A custom Group edit form |
* A plugin that allows for custom forms to be used for datasets based on | * A plugin that allows for custom forms to be used for datasets based on |
their "type". | their "type". |
* A custom User registration and edition form | * A custom User registration and edition form |
* Some simple template customisations | * Some simple template customisations |
Installation | Installation |
============ | ============ |
To install this package, from your CKAN virtualenv, run the following from your CKAN base folder (e.g. ``pyenv/``):: | To install this package, from your CKAN virtualenv, run the following from your CKAN base folder (e.g. ``pyenv/``):: |
pip install -e git+https://github.com/okfn/ckanext-example#egg=ckanext-example | pip install -e git+https://github.com/okfn/ckanext-example#egg=ckanext-example |
Then activate it by setting ``ckan.plugins = example`` in your main ``ini``-file. | Then activate it by setting ``ckan.plugins = example`` in your main ``ini``-file. |
Orientation | Orientation |
=========== | =========== |
* Examine the source code, starting with ``ckanext/example/plugin.py`` | * Examine the source code, starting with ``ckanext/example/plugin.py`` |
* To understand the nuts and bolts of this file, which is a CKAN | * To understand the nuts and bolts of this file, which is a CKAN |
*Extension*, read in conjunction with the "Extension | *Extension*, read in conjunction with the "Extension |
documentation": http://docs.ckan.org/en/latest/plugins.html | documentation": http://docs.ckan.org/en/latest/plugins.html |
* One thing the extension does is set the values of | * One thing the extension does is set the values of |
``extra_public_paths`` and ``extra_template_paths`` in the CKAN | ``extra_public_paths`` and ``extra_template_paths`` in the CKAN |
config, which are "documented | config, which are "documented |
here": http://docs.ckan.org/en/latest/configuration.html#extra-template-paths | here": http://docs.ckan.org/en/latest/configuration.html#extra-template-paths |
* These are set to point at directories within | * These are set to point at directories within |
``ckanext/example/theme/`` (in this package). Here we: | ``ckanext/example/theme/`` (in this package). Here we: |
* override the home page HTML ``ckanext/example/theme/templates/home/index.html`` | * override the home page HTML ``ckanext/example/theme/templates/home/index.html`` |
* provide some extra style by serving ``extra.css`` (which is loaded using the ``ckan.template_head_end`` option | * provide some extra style by serving ``extra.css`` (which is loaded using the ``ckan.template_head_end`` option |
* customise the navigation and header of the main template in the file ``layout.html``. | * customise the navigation and header of the main template in the file ``layout.html``. |
The latter file is a great place to make global theme alterations. | The latter file is a great place to make global theme alterations. |
It uses the _layout template_ pattern "described in the Genshi | It uses the _layout template_ pattern "described in the Genshi |
documentation":http://genshi.edgewall.org/wiki/GenshiTutorial#AddingaLayoutTemplate. | documentation":http://genshi.edgewall.org/wiki/GenshiTutorial#AddingaLayoutTemplate. |
This allows you to use Xpath selectors to override snippets of HTML | This allows you to use Xpath selectors to override snippets of HTML |
globally. | globally. |
* The custom package edit form at ``package_form.py`` follows a deprecated | * The custom package edit form at ``package_form.py`` follows a deprecated |
way to make a form (using FormAlchemy). This part of the Example Theme needs | way to make a form (using FormAlchemy). This part of the Example Theme needs |
updating. In the meantime, follow the instructions at: | updating. In the meantime, follow the instructions at: |
http://readthedocs.org/docs/ckan/en/latest/forms.html | http://readthedocs.org/docs/ckan/en/latest/forms.html |
Example Tags With Vocabularies | |
============================== | |
To add example tag vocabulary data to the database, from the ckanext-example directory run: | |
:: | |
paster example create-example-vocabs -c <path to your ckan config file> | |
This data can be removed with | |
:: | |
paster example clean -c <path to your ckan config file> | |
from ckan import model | from ckan import model |
from ckan.lib.cli import CkanCommand | from ckan.lib.cli import CkanCommand |
from ckan.logic import get_action, NotFound | from ckan.logic import get_action, NotFound |
import forms | import forms |
import logging | import logging |
log = logging.getLogger() | log = logging.getLogger() |
class ExampleCommand(CkanCommand): | class ExampleCommand(CkanCommand): |
''' | ''' |
CKAN Example Extension | CKAN Example Extension |
Usage:: | Usage:: |
paster example create-example-vocabs -c <path to config file> | paster example create-example-vocabs -c <path to config file> |
paster example clean -c <path to config file> | paster example clean -c <path to config file> |
- Remove all data created by ckanext-example | - Remove all data created by ckanext-example |
The commands should be run from the ckanext-example directory. | The commands should be run from the ckanext-example directory. |
''' | ''' |
summary = __doc__.split('\n')[0] | summary = __doc__.split('\n')[0] |
usage = __doc__ | usage = __doc__ |
def command(self): | def command(self): |
''' | ''' |
Parse command line arguments and call appropriate method. | Parse command line arguments and call appropriate method. |
''' | ''' |
if not self.args or self.args[0] in ['--help', '-h', 'help']: | if not self.args or self.args[0] in ['--help', '-h', 'help']: |
print ExampleCommand.__doc__ | print ExampleCommand.__doc__ |
return | return |
cmd = self.args[0] | cmd = self.args[0] |
self._load_config() | self._load_config() |
if cmd == 'create-example-vocabs': | if cmd == 'create-example-vocabs': |
self.create_example_vocabs() | self.create_example_vocabs() |
if cmd == 'clean': | |
self.clean() | |
else: | else: |
log.error('Command "%s" not recognized' % (cmd,)) | log.error('Command "%s" not recognized' % (cmd,)) |
def create_example_vocabs(self): | def create_example_vocabs(self): |
''' | ''' |
Adds example vocabularies to the database if they don't already exist. | Adds example vocabularies to the database if they don't already exist. |
''' | ''' |
user = get_action('get_site_user')({'model': model, 'ignore_auth': True}, {}) | user = get_action('get_site_user')({'model': model, 'ignore_auth': True}, {}) |
context = {'model': model, 'session': model.Session, 'user': user['name']} | context = {'model': model, 'session': model.Session, 'user': user['name']} |
try: | try: |
data = {'id': forms.GENRE_VOCAB} | data = {'id': forms.GENRE_VOCAB} |
get_action('vocabulary_show')(context, data) | get_action('vocabulary_show')(context, data) |
log.info("Example genre vocabulary already exists, skipping.") | log.info("Example genre vocabulary already exists, skipping.") |
except NotFound: | except NotFound: |
log.info("Creating vocab %s" % forms.GENRE_VOCAB) | log.info("Creating vocab %s" % forms.GENRE_VOCAB) |
data = {'name': forms.GENRE_VOCAB} | data = {'name': forms.GENRE_VOCAB} |
vocab = get_action('vocabulary_create')(context, data) | vocab = get_action('vocabulary_create')(context, data) |
log.info("Adding tag %s to vocab %s" % ('jazz', forms.GENRE_VOCAB)) | log.info("Adding tag %s to vocab %s" % ('jazz', forms.GENRE_VOCAB)) |
data = {'name': 'jazz', 'vocabulary_id': vocab['id']} | data = {'name': 'jazz', 'vocabulary_id': vocab['id']} |
get_action('tag_create')(context, data) | get_action('tag_create')(context, data) |
log.info("Adding tag %s to vocab %s" % ('soul', forms.GENRE_VOCAB)) | log.info("Adding tag %s to vocab %s" % ('soul', forms.GENRE_VOCAB)) |
data = {'name': 'soul', 'vocabulary_id': vocab['id']} | data = {'name': 'soul', 'vocabulary_id': vocab['id']} |
get_action('tag_create')(context, data) | get_action('tag_create')(context, data) |
try: | try: |
data = {'id': forms.COMPOSER_VOCAB} | data = {'id': forms.COMPOSER_VOCAB} |
get_action('vocabulary_show')(context, data) | get_action('vocabulary_show')(context, data) |
log.info("Example composer vocabulary already exists, skipping.") | log.info("Example composer vocabulary already exists, skipping.") |
except NotFound: | except NotFound: |
log.info("Creating vocab %s" % forms.COMPOSER_VOCAB) | log.info("Creating vocab %s" % forms.COMPOSER_VOCAB) |
data = {'name': forms.COMPOSER_VOCAB} | data = {'name': forms.COMPOSER_VOCAB} |
vocab = get_action('vocabulary_create')(context, data) | vocab = get_action('vocabulary_create')(context, data) |
log.info("Adding tag %s to vocab %s" % ('Bob Mintzer', forms.COMPOSER_VOCAB)) | log.info("Adding tag %s to vocab %s" % ('Bob Mintzer', forms.COMPOSER_VOCAB)) |
data = {'name': 'Bob Mintzer', 'vocabulary_id': vocab['id']} | data = {'name': 'Bob Mintzer', 'vocabulary_id': vocab['id']} |
get_action('tag_create')(context, data) | get_action('tag_create')(context, data) |
log.info("Adding tag %s to vocab %s" % ('Steve Lewis', forms.COMPOSER_VOCAB)) | log.info("Adding tag %s to vocab %s" % ('Steve Lewis', forms.COMPOSER_VOCAB)) |
data = {'name': 'Steve Lewis', 'vocabulary_id': vocab['id']} | data = {'name': 'Steve Lewis', 'vocabulary_id': vocab['id']} |
get_action('tag_create')(context, data) | get_action('tag_create')(context, data) |
def clean(self): | |
log.error("Clean command not yet implemented") | |
import os | import os |
import logging | import logging |
from pylons import tmpl_context as c | |
from ckan.authz import Authorizer | from ckan.authz import Authorizer |
from ckan.logic.converters import convert_to_extras,\ | from ckan.logic.converters import convert_to_extras,\ |
convert_from_extras, convert_to_tags, convert_from_tags, free_tags_only | convert_from_extras, convert_to_tags, convert_from_tags, free_tags_only |
from ckan.logic import get_action, NotFound | from ckan.logic import get_action, NotFound |
from ckan.logic.schema import package_form_schema, group_form_schema | from ckan.logic.schema import package_form_schema, group_form_schema |
from ckan.lib.base import c, model | from ckan.lib.base import c, model |
from ckan.plugins import IDatasetForm, IGroupForm, IConfigurer | from ckan.plugins import IDatasetForm, IGroupForm, IConfigurer |
from ckan.plugins import IGenshiStreamFilter | |
from ckan.plugins import implements, SingletonPlugin | from ckan.plugins import implements, SingletonPlugin |
from ckan.lib.navl.validators import ignore_missing, keep_extras | from ckan.lib.navl.validators import ignore_missing, keep_extras |
log = logging.getLogger(__name__) | log = logging.getLogger(__name__) |
GENRE_VOCAB = u'genre_vocab' | GENRE_VOCAB = u'genre_vocab' |
COMPOSER_VOCAB = u'composer_vocab' | COMPOSER_VOCAB = u'composer_vocab' |
class ExampleGroupForm(SingletonPlugin): | class ExampleGroupForm(SingletonPlugin): |
"""This plugin demonstrates how a class packaged as a CKAN | """This plugin demonstrates how a class packaged as a CKAN |
extension might extend CKAN behaviour by providing custom forms | extension might extend CKAN behaviour by providing custom forms |
based on the type of a Group. | based on the type of a Group. |
In this case, we implement two extension interfaces to provide custom | In this case, we implement two extension interfaces to provide custom |
forms for specific types of group. | forms for specific types of group. |
- ``IConfigurer`` allows us to override configuration normally | - ``IConfigurer`` allows us to override configuration normally |
found in the ``ini``-file. Here we use it to specify where the | found in the ``ini``-file. Here we use it to specify where the |
form templates can be found. | form templates can be found. |
- ``IGroupForm`` allows us to provide a custom form for a dataset | - ``IGroupForm`` allows us to provide a custom form for a dataset |
based on the 'type' that may be set for a group. Where the | based on the 'type' that may be set for a group. Where the |
'type' matches one of the values in group_types then this | 'type' matches one of the values in group_types then this |
class will be used. | class will be used. |
""" | """ |
implements(IGroupForm, inherit=True) | implements(IGroupForm, inherit=True) |
implements(IConfigurer, inherit=True) | implements(IConfigurer, inherit=True) |
def update_config(self, config): | def update_config(self, config): |
""" | """ |
This IConfigurer implementation causes CKAN to look in the | This IConfigurer implementation causes CKAN to look in the |
```templates``` directory when looking for the group_form() | ```templates``` directory when looking for the group_form() |
""" | """ |
here = os.path.dirname(__file__) | here = os.path.dirname(__file__) |
rootdir = os.path.dirname(os.path.dirname(here)) | rootdir = os.path.dirname(os.path.dirname(here)) |
template_dir = os.path.join(rootdir, 'ckanext', | template_dir = os.path.join(rootdir, 'ckanext', |
'example', 'theme', 'templates') | 'example', 'theme', 'templates') |
config['extra_template_paths'] = ','.join([template_dir, | config['extra_template_paths'] = ','.join([template_dir, |
config.get('extra_template_paths', '')]) | config.get('extra_template_paths', '')]) |
def group_form(self): | def group_form(self): |
""" | """ |
Returns a string representing the location of the template to be | Returns a string representing the location of the template to be |
rendered. e.g. "forms/group_form.html". | rendered. e.g. "forms/group_form.html". |
""" | """ |
return 'forms/group_form.html' | return 'forms/group_form.html' |
def group_types(self): | def group_types(self): |
""" | """ |
Returns an iterable of group type strings. | Returns an iterable of group type strings. |
If a request involving a group of one of those types is made, then | If a request involving a group of one of those types is made, then |
this plugin instance will be delegated to. | this plugin instance will be delegated to. |
There must only be one plugin registered to each group type. Any | There must only be one plugin registered to each group type. Any |
attempts to register more than one plugin instance to a given group | attempts to register more than one plugin instance to a given group |
type will raise an exception at startup. | type will raise an exception at startup. |
""" | """ |
return ["testgroup"] | return ["testgroup"] |
def is_fallback(self): | def is_fallback(self): |
""" | """ |
Returns true iff this provides the fallback behaviour, when no other | Returns true iff this provides the fallback behaviour, when no other |
plugin instance matches a group's type. | plugin instance matches a group's type. |
As this is not the fallback controller we should return False. If | As this is not the fallback controller we should return False. If |
we were wanting to act as the fallback, we'd return True | we were wanting to act as the fallback, we'd return True |
""" | """ |
return False | return False |
def form_to_db_schema(self): | def form_to_db_schema(self): |
""" | """ |
Returns the schema for mapping group data from a form to a format | Returns the schema for mapping group data from a form to a format |
suitable for the database. | suitable for the database. |
""" | """ |
return group_form_schema() | return group_form_schema() |
def db_to_form_schema(self): | def db_to_form_schema(self): |
""" | """ |
Returns the schema for mapping group data from the database into a | Returns the schema for mapping group data from the database into a |
format suitable for the form (optional) | format suitable for the form (optional) |
""" | """ |
return {} | return {} |
def check_data_dict(self, data_dict): | def check_data_dict(self, data_dict): |
""" | """ |
Check if the return data is correct. | Check if the return data is correct. |
raise a DataError if not. | raise a DataError if not. |
""" | """ |
def setup_template_variables(self, context, data_dict): | def setup_template_variables(self, context, data_dict): |
""" | """ |
Add variables to c just prior to the template being rendered. | Add variables to c just prior to the template being rendered. |
""" | """ |
class ExampleDatasetForm(SingletonPlugin): | class ExampleDatasetForm(SingletonPlugin): |
"""This plugin demonstrates how a theme packaged as a CKAN | """This plugin demonstrates how a theme packaged as a CKAN |
extension might extend CKAN behaviour. | extension might extend CKAN behaviour. |
In this case, we implement three extension interfaces: | In this case, we implement three extension interfaces: |
- ``IConfigurer`` allows us to override configuration normally | - ``IConfigurer`` allows us to override configuration normally |
found in the ``ini``-file. Here we use it to specify where the | found in the ``ini``-file. Here we use it to specify where the |
form templates can be found. | form templates can be found. |
- ``IDatasetForm`` allows us to provide a custom form for a dataset | - ``IDatasetForm`` allows us to provide a custom form for a dataset |
based on the type_name that may be set for a package. Where the | based on the type_name that may be set for a package. Where the |
type_name matches one of the values in package_types then this | type_name matches one of the values in package_types then this |
class will be used. | class will be used. |
""" | """ |
implements(IDatasetForm, inherit=True) | implements(IDatasetForm, inherit=True) |
implements(IConfigurer, inherit=True) | implements(IConfigurer, inherit=True) |
implements(IGenshiStreamFilter, inherit=True) | |
def update_config(self, config): | def update_config(self, config): |
""" | """ |
This IConfigurer implementation causes CKAN to look in the | This IConfigurer implementation causes CKAN to look in the |
```templates``` directory when looking for the package_form() | ```templates``` directory when looking for the package_form() |
""" | """ |
here = os.path.dirname(__file__) | here = os.path.dirname(__file__) |
rootdir = os.path.dirname(os.path.dirname(here)) | rootdir = os.path.dirname(os.path.dirname(here)) |
template_dir = os.path.join(rootdir, 'ckanext', | template_dir = os.path.join(rootdir, 'ckanext', |
'example', 'theme', 'templates') | 'example', 'theme', 'templates') |
config['extra_template_paths'] = ','.join([template_dir, | config['extra_template_paths'] = ','.join([template_dir, |
config.get('extra_template_paths', '')]) | config.get('extra_template_paths', '')]) |
def package_form(self): | def package_form(self): |
""" | """ |
Returns a string representing the location of the template to be | Returns a string representing the location of the template to be |
rendered. e.g. "package/new_package_form.html". | rendered. e.g. "package/new_package_form.html". |
""" | """ |
return 'forms/dataset_form.html' | return 'forms/dataset_form.html' |
def is_fallback(self): | def is_fallback(self): |
""" | """ |
Returns true iff this provides the fallback behaviour, when no other | Returns true iff this provides the fallback behaviour, when no other |
plugin instance matches a package's type. | plugin instance matches a package's type. |
As this is not the fallback controller we should return False. If | As this is not the fallback controller we should return False. If |
we were wanting to act as the fallback, we'd return True | we were wanting to act as the fallback, we'd return True |
""" | """ |
return True | return True |
def package_types(self): | def package_types(self): |
""" | """ |
Returns an iterable of package type strings. |