The Provides system

The Provides system is Shuup’s mechanism for discovering and loading components, both first-party and third-party. Shuup apps use the provides system in various ways.

The core itself uses Provides for discovering method and supplier modules.
shuup.admin uses Provides to load admin modules, form customizations etc.
shuup.front uses it for URLconf overrides etc.

The provide categories used by Shuup are listed in Provide Categories, but you can also define your own categories as you wish.

Todo

Document the various ways better.

Provides are grouped under different categories, such as admin_module, xtheme_plugin, front_urls, etc.

Declaring Provides

Shuup uses the Django 1.7+ AppConfig system to declare provides.

Quite simply, a developer needs only include a dict with provide categories as the keys and lists of loading specs as values for new provides to be discovered.

class PigeonAppConfig(AppConfig):

    provides = {
        'service_provider_admin_form': [
            'pigeon.admin_forms:PigeonShippingAdminForm',
        ],
    }

Note

Some provides also require the class named by the spec string to include an identifier field. Refer to the implementation guides for particular functionalities for details.

Blacklisting Provides

Shuup also supports blacklisting unwanted provides. This is useful when one want to disable some features like shipping and payment methods provided by a single app. This way, it is easy to select which provides should be loaded by Shuup. To blacklist provides, you need to set a special Django setting named SHUUP_PROVIDES_BLACKLIST:

SHUUP_PROVIDES_BLACKLIST = {
     'service_provider_admin_form': [
         'pigeon.admin_forms:PigeonShippingAdminForm'
     ]
 }

This will allow the spec pigeon.admin_forms:PigeonShippingAdminForm from category service_provider_admin_form to be loaded.

Using Provides

Provide management functions are found in the shuup.apps.provides module.

In general, the shuup.apps.provides.get_provide_objects method is your most useful entry point.

Provide Categories

Core

admin_category_form_part: Additional FormPart classes for Category editing. See example.
admin_contact_form_part: Additional FormPart classes for Contact editing. See example.
admin_contact_group_form_part: Additional FormPart classes for ContactGroup editing. See example.
admin_contact_toolbar_action_item: Additional DropdownItem subclass for Contact detail action buttons.
admin_contact_edit_toolbar_button: Additional BaseActionButton subclasses for Contact edit. Subclass init should take current contact as a parameter.
admin_contact_section: Additional Section subclasses for Contact detail sections.
admin_extend_create_shipment_form: Allows providing extension for shipment creation in admin. Should implement the FormModifier interface.
admin_main_menu_updater: Allows updating the Admin Main Menu with new elements. The objects offered through this provide should inherit from ~shuup.core.utils.menu.MainMenuUpdater class.
admin_mass_actions_provider`: Object that provides mass actions to all views. Providers must subclass from shuup.admin.utils.picotable.PicotableMassActionProvider and implement the get_mass_actions_for_view method.
admin_module: Admin module classes. Practically all of the functionality in the admin is built via admin modules.
admin_object_selector: Object selector classes for filtering models in select2 objects. Providers must subclass from BaseAdminObjectSelector class.
admin_order_information: Additional information rows for Order detail page. Provide objects should inherit from OrderInformation class.
admin_product_form_part: Additional FormPart classes for Product editing. (This is used by pricing modules, for instance.) See example.
admin_product_section: Additional Section subclasses for Product edit sections.
admin_product_validator: Provide an AdminProductValidator class, which validates a product according to some criteria.
admin_product_toolbar_action_item: Additional DropdownItem subclass for Product edit action buttons.
admin_template_injector: Allow snippet injection inside admin templates. The classes must inherit from the ~shuup.admin.base.AdminTemplateInjector class.
admin_shop_edit_toolbar_button: Additional BaseActionButton subclasses for Shop edit. Subclass init should take current shop as a parameter. Current shop is passed to static method visible_for_object to check whether to actually show the item.
admin_shop_form_part: Additional FormPart classes for Shop editing. See example.
admin_toolbar_button_provider: Object that provides buttons to all toolbars. Providers must subclass from shuup.admin.toolbar.BaseToolbarButtonProvider and implement the get_buttons_for_view method.
basket_command_middleware: Injects a middleware in the basket command dispatcher that can be used to mutate the basket kwargs and response and execute additional steps with the basket once a command is invoked.
customer_dashboard_items: Classes to parse customer dashboard items from. These are subclasses of shuup.front.utils.dashboard.DashboardItem
discount_module: DiscountModule for pricing system.
front_extend_product_list_form: Allows providing extension for product list form. Should implement the ProductListFormModifier interface.
front_service_checkout_phase_provider: Allows providing a custom checkout phase for a service (e.g. payment method or shipping method). Should implement the ServiceCheckoutPhaseProvider interface.
front_template_helper_namespace: Additional namespaces to install in the shuup “package” within template contexts. .. seealso:: Custom Template Helper Functions
admin_order_toolbar_action_item: Additional DropdownItem subclass for Order detail action buttons. Current order is passed to subclass init and static method visible_for_object is called for the subclass to check whether to actually show the item.
admin_order_section: Additional Section subclasses for Order detail sections.
front_model_url_resolver: List of functions that resolve a model instance into an object URL. The first valid url returned by a provide will be used by the caller.
admin_model_url_resolver: List of functions that resolve a model instance into an object URL. The first valid url returned by a provide will be used by the called.
admin_browser_config_provider`: List of classes that implements shuup.admin.browser_config.BaseBrowserConfigProvider class. It can implement the get_browser_urls method which should returns a dictionary of urls names that should be exported to the browser through the window.ShuupAdminConfig.browserUrls object. The returned dictionary should have the url name as the value, which will be reversed when rendering the templates. It can also implement the get_gettings method which should returns a dictionary. The returned data will be converted into JSON and exported to the browser through the window.ShuupAdminConfig.settings object.
front_menu_extender: Additional menu items provided by addons. These should be subclassed from FrontMenuExtender.
front_product_order_form: List of order forms which are subclasses of ProductOrderForm. These forms are shown on product detail page in front as well as previews etc.
front_registration_field_provider: List of FormFieldProvider classes. These classes provide FormFieldDefinition objects which extend registration forms accross the Shuup front.
checkout_confirm_form_field_provider: List of FormFieldProvider classes. These classes provide FormFieldDefinition objects which extend checkout confirm form.
front_auth_form_field_provider: List of FormFieldProvider classes. These classes provide FormFieldDefinition objects which extend authentication forms accross the Shuup front.
front_company_registration_form_provider: List of FormDefProvider classes. These classes provide FormDefinition objects which extend the CompanyRegistrationForm with form_defs.
front_urls: Lists of frontend URLs to be appended to the usual frontend URLs.
front_urls_post: Lists of frontend URLs to be appended to the usual frontend URLs, even after front_urls. Most of the time, front_urls should do.
front_urls_pre: Lists of frontend URLs to be prepended to the usual frontend URLs. Most of the time, front_urls should do.
front_line_properties_descriptor: Object that returns properties for order source lines and order lines to be rendered in the basket and order detail views. The objects must inherit from the BaseLinePropertiesDescriptor base class.
notify_action: Notification framework Action classes.
notify_condition: Notification framework Condition classes.
notify_event: Notification framework Event classes.
notify_script_template: Notification framework ScriptTemplate classes.
order_printouts_delivery_extra_fields: Additional information rows for order delivery printout. Provide objects should inherit from PrintoutDeliveryExtraInformation class.
order_source_modifier_module: OrderSourceModifierModule for modifying order source, e.g. in its get_final_lines.
order_source_validator: List of classes that validate a given OrderSource and return an error iterator. The class must have a get_validation_errors class method which receives the order_source and returns/yields ValidationError instances.
pricing_module: Pricing module classes; the pricing module in use is set with the SHUUP_PRICING_MODULE setting.
product_kind_specs: List of classes that define the product kinds that can be used in the platform. The classes must implement the ProductKindSpec base class. It is specially used to control which supplier modules can handle certain types of products and also to hide products from the normal admin product list.
service_behavior_component_form: Forms for creating service behavior components in Shop Admin. When creating a custom service behavior component, provide a form for it via this provide.
service_provider_admin_form: Forms for creating service providers in Shop Admin. When creating a custom service provider (e.g. carrier or payment processor), provide a form for it via this provide.
carrier_wizard_form_def: Formdefs for creating carriers (and their service(s)) through the shop setup wizard.
payment_processor_wizard_form_def: Formdefs for creating payment processors (and their service(s)) through the shop setup wizard.
product_context_extra: Additional context data for the front product views. Provide objects should inherit from ProductContextExtra class.
product_subscription_option_provider: Returns subscription options for a given ProductSubscriptionContext context. The provider must inherit from the base class BaseProductSubscriptionOptionProvider.
supplier_module: Supplier module classes (deriving from BaseSupplierModule), as used by Supplier.
tax_module: Tax module classes; the tax module in use is set with the SHUUP_TAX_MODULE setting.
xtheme: XTheme themes (full theme sets).
xtheme_layout: XTheme layouts (to split placeholders different types of layouts with different visibilities).
xtheme_plugin: XTheme plugins (that are placed into layouts within themes).
xtheme_resource_injection: XTheme resources injection function that takes current context and content as parameters.
xtheme_snippet_blocker: Blocker classes that can prevent a global snippet from being injected

Campaigns Provide Categories

campaign_catalog_filter: Filters that filter product catalog queryset to find the matching campaigns.
campaign_context_condition: Context Conditions that matches against the current context in shop to see if campaign matches.
campaign_product_discount_effect_form: Form for handling product discount effects of a catalog campaign. Should be a ModelForm with its model being a subclass of ProductDiscountEffect.
campaign_basket_condition: Conditions that matches against the order source or source lines in basket.
campaign_basket_discount_effect_form: Form for handling discount effects of a basket campaign. Should be a ModelForm with its model being a subclass of BasketDiscountEffect.
campaign_basket_line_effect_form: Form for handling line effects of a basket campaign. Should be a ModelForm with its model being a subclass of BasketLineEffect.

Reports Provide Categories

reports: Class to handle report data collection. Should be a subclass of ShuupReportBase.
report_writer_populator: List of functions to populate report writers. This allows the creation of custom output formats. Should follow the signature of populate_default_writers.

Simple CMS Provide Categories

admin_page_form_part: Additional FormPart classes for Page editing. See example.
simple_cms_template: List of available template objects that can be used to render CMS pages.

List of objects that have provides key as attributes

Some objects have attributes that contain a provide key which are used to load provides dynamically. They are specially used in mixins when they can be attached to some class which overrides the attribute with its own provide key name, making it easier to extend provides related to class. Here is the list of objects that have this attribute which can be overrided on a specialization:

FormPartsViewMixin.form_part_class_provide_key: Adds form parts to a view dynamically. Each view will have a custom provide key value.
View.toolbar_buttons_provider_key: Adds buttons to a view’s toolbar. Each view will have a custom provide key value. Only views that use toolbars can use this attribute, as in PicotableViewMixin. Check CategoryListView for an example.
View.mass_actions_provider_key: Adds mass actions view. Each view will have a custom provide key value. Only views that inherints from PicotableListView or PicotableViewMixin will have mass actions added. All providers must inherit from PicotableMassActionProvider base class. Check CategoryListView for an example.