This page documents the variables that are available to custom templates
for each of Datasette's core pages. See :ref:`customization_custom_templates`
for how to provide your own templates.
The variables documented here are a stable contract: custom templates that
use them will continue to work across Datasette releases, up until the next
major version (Datasette 2.0). Anything present in the template context but
not documented on this page is not part of that contract and may change or
be removed in any release.
You can inspect the full context for any page by starting Datasette with
``--setting template_debug 1`` and adding ``?_context=1`` to the page URL.
.. [[[cog
from template_context_doc import template_context
template_context(cog)
.. ]]]
Base context
------------
These variables are available on every page rendered by Datasette, including pages rendered by plugins that use :ref:`datasette.render_template() <datasette_render_template>`. Plugins can add additional variables using the :ref:`plugin_hook_extra_template_vars` hook.
The current :ref:`Request object <internals_request>`, or None. Common properties include ``request.path``, ``request.args``, ``request.actor``, ``request.url_vars`` and ``request.host``.
Async function returning breadcrumb navigation items for the current page. Call it with ``request=request`` plus optional ``database=`` and ``table=`` arguments; it returns a list of ``{"href": url, "label": label}`` dictionaries.
Object with methods for constructing URLs within Datasette. Common methods include ``urls.instance()``, ``urls.database(database)``, ``urls.table(database, table)``, ``urls.query(database, query)``, ``urls.row(database, table, row_path)`` and ``urls.static(path)`` - see :ref:`internals_datasette_urls`.
The currently authenticated actor dictionary, or None. Actors usually include an ``id`` key and may include any other keys supplied by authentication plugins.
Async function returning links for the Datasette application menu, including links added by plugins. Each item is a link dictionary with ``href`` and ``label`` keys. See :ref:`plugin_hook_menu_links`; for page action menus that can also include JavaScript-backed buttons, see :ref:`plugin_actions`.
List of JavaScript snippets contributed by plugins using :ref:`plugin_hook_extra_body_script`. Each item is a dictionary with ``script`` containing JavaScript source and ``module`` indicating whether Datasette will wrap it in ``<script type="module">``; otherwise Datasette wraps it in a regular ``<script>`` block.
Function returning any messages set for the current user, clearing them in the process. Returns a list of ``(message, type)`` pairs, where ``type`` is one of Datasette's ``INFO``, ``WARNING`` or ``ERROR`` constants.
List of extra CSS stylesheets to include on the page. Each item is a dictionary with ``url`` and optional ``sri`` keys, from plugins and configuration.
List of extra JavaScript URLs to include on the page. Each item is a dictionary with ``url`` plus optional ``sri`` and ``module`` keys, from plugins and configuration.
List of names of databases attached to this SQLite connection. This is only populated for the special ``/_memory`` database when Datasette is started with ``--crossdb`` for :ref:`cross_database_queries`.
Async callable returning action items for the database menu. Each item is either a link with ``href``, ``label`` and optional ``description`` keys, or a button with ``type: "button"``, ``label``, optional ``description`` and optional ``attrs``. See :ref:`plugin_actions` and :ref:`plugin_hook_database_actions`.
JSON data used by JavaScript on the database page. Currently ``{}`` or ``{"createTable": {...}}`` where ``createTable`` includes ``path``, ``foreignKeyTargetsPath``, ``databaseName``, ``columnTypes``, ``defaultExpressions`` and optional ``customColumnTypes``.
List of ``StoredQuery`` objects. Each has attributes including ``name``, ``sql``, ``title``, ``description``, ``description_html``, ``hide_sql``, ``fragment``, ``parameters``, ``is_write`` and ``private``.
List of ``DatabaseTable`` objects describing tables in the database. Each item has ``name``, ``columns``, ``primary_keys``, ``count``, ``count_truncated``, ``hidden``, ``fts_table``, ``foreign_keys`` and ``private`` attributes. ``count_truncated`` is true if ``count`` is a capped lower bound rather than an exact total.
Metadata dictionary for the database or stored query. Stored query metadata may include options such as ``hide_sql``, ``on_success_message`` and ``on_error_redirect``.
Async callable returning action items for the query menu. Each item is either a link with ``href``, ``label`` and optional ``description`` keys, or a button with ``type: "button"``, ``label``, optional ``description`` and optional ``attrs``. See :ref:`plugin_actions` and :ref:`plugin_hook_query_actions`.
List of ``DatabaseTable`` objects describing tables in the database. Each item has ``name``, ``columns``, ``primary_keys``, ``count``, ``count_truncated``, ``hidden``, ``fts_table``, ``foreign_keys`` and ``private`` attributes. ``count_truncated`` is true if ``count`` is a capped lower bound rather than an exact total.
Async callable returning table or view actions made available by core and plugin hooks. Each item is either a link with ``href``, ``label`` and optional ``description`` keys, or a button with ``type: "button"``, ``label``, optional ``description`` and optional ``attrs``. See :ref:`plugin_actions`, :ref:`plugin_hook_table_actions` and :ref:`plugin_hook_view_actions`.
Column metadata used by the HTML table display. Each item includes ``name``, ``sortable``, ``is_pk``, ``type``, ``notnull``, ``description``, ``column_type`` and ``column_type_config`` keys.
Rows formatted for the HTML table display. Each row is iterable and contains cell dictionaries with ``column``, ``value``, ``raw`` and ``value_type`` keys; table pages may also provide ``pk_path``, ``row_path`` and ``row_label`` attributes on each row object.
List of foreign key columns that can be expanded with labels. Each item is a ``(foreign_key, label_column)`` pair where ``foreign_key`` is the SQLite foreign key dictionary and ``label_column`` is the label column in the referenced table, or ``None``.
Extra where clauses from ``?_where=`` for display in the UI. Each item has ``text`` for the SQL fragment and ``remove_url`` for a URL that removes that fragment.
Results of facets calculated against this data. A dictionary with ``results`` and ``timed_out`` keys: ``results`` maps facet names to facet dictionaries with ``name``, ``type``, ``results`` and URL keys, and each facet result item includes ``value``, ``label``, ``count`` and ``toggle_url``.
Metadata dictionary for the table, database or stored query. Table and row metadata include a ``columns`` dictionary mapping column names to descriptions; stored query metadata returns the stored query configuration.
Function for building the current path with modified query string arguments. Pass the current ``request`` and a dictionary of argument names to replacement values, using ``None`` to remove an argument.
Information needed to build an interface for assigning column types, or ``None`` if unavailable. When present it has ``path`` and ``columns`` keys; ``columns`` maps column names to ``current`` and ``options`` values.
Suggestions for facets that might return interesting results. Each item is a dictionary with ``name`` and ``toggle_url`` keys, and may include extra keys such as ``type`` or ``label`` depending on the facet class.
Information needed to enable the alter table UI, or ``None`` if altering this table is not available to the current actor. When present it has ``path``, ``tableName``, ``columns``, ``primaryKeys``, ``columnTypes``, ``defaultExpressions`` and ``foreignKeyTargetsPath`` keys, plus optional ``customColumnTypes`` and ``dropPath`` keys.
Information needed to enable the row insertion UI, or ``None`` if row insertion is not available to the current actor. When present it has ``path``, ``tableName``, ``columns`` and ``primaryKeys`` keys; each column includes ``name``, ``sqlite_type``, ``notnull``, ``default``, ``has_default``, ``is_pk``, ``value_kind`` and ``column_type`` keys.
JSON data used by JavaScript on the table page. Includes ``database``, ``table`` and ``tableUrl``, plus optional ``foreignKeys`` mapping column names to autocomplete URLs, optional ``insertRow`` data and optional ``alterTable`` data.
Column metadata used by the HTML table display. Each item includes ``name``, ``sortable``, ``is_pk``, ``type``, ``notnull``, ``description``, ``column_type`` and ``column_type_config`` keys.
Rows formatted for the HTML table display. Each row is iterable and contains cell dictionaries with ``column``, ``value``, ``raw`` and ``value_type`` keys.
List of tables that link to this row using foreign keys. Each item includes the foreign key fields plus ``count`` for matching rows and ``link`` for the filtered table URL.
Metadata dictionary for the table, database or stored query. Table and row metadata include a ``columns`` dictionary mapping column names to descriptions; stored query metadata returns the stored query configuration.
Row actions made available by core and plugin hooks. Each item is either a link with ``href``, ``label`` and optional ``description`` keys, or a button with ``type: "button"``, ``label``, optional ``description`` and optional ``attrs``. See :ref:`plugin_actions` and :ref:`plugin_hook_row_actions`.
JSON data used by JavaScript on the row page. Includes ``database``, ``table`` and ``tableUrl``, plus optional ``foreignKeys`` mapping column names to autocomplete URLs.
