remote/datasette
1
0
Fork 0
mirror of https://github.com/simonw/datasette.git synced 2026-06-24 01:34:41 +02:00
Code Issues Projects Releases Packages Wiki Activity

Add count_truncated template context

Browse source
This commit is contained in:
Simon Willison 2026-06-22 19:47:21 -07:00
commit 4d031c8562
8 changed files with 96 additions and 25 deletions
Download patch file Download diff file Expand all files Collapse all files

2
datasette/templates/database.html
View file

@ -76,7 +76,7 @@
<div class="db-table">
<h3><a href="{{ urls.table(database, table.name) }}">{{ table.name }}</a>{% if table.private %} 🔒{% endif %}{% if table.hidden %}<em> (hidden)</em>{% endif %}</h3>
<p><em>{% for column in table.columns %}{{ column }}{% if not loop.last %}, {% endif %}{% endfor %}</em></p>
<p>{% if table.count is none %}Many rows{% elif table.count == count_limit + 1 %}&gt;{{ "{:,}".format(count_limit) }} rows{% else %}{{ "{:,}".format(table.count) }} row{% if table.count == 1 %}{% else %}s{% endif %}{% endif %}</p>
<p>{% if table.count is none %}Many rows{% elif table.count_truncated %}&gt;{{ "{:,}".format(table.count - 1) }} rows{% else %}{{ "{:,}".format(table.count) }} row{% if table.count == 1 %}{% else %}s{% endif %}{% endif %}</p>
</div>
{% endif %}
{% endfor %}

4
datasette/templates/table.html
View file

@ -1,6 +1,6 @@
{% extends "base.html" %}
{% block title %}{{ database }}: {{ table }}: {% if count or count == 0 %}{{ "{:,}".format(count) }} row{% if count == 1 %}{% else %}s{% endif %}{% endif %}{% if human_description_en %} {{ human_description_en }}{% endif %}{% endblock %}
{% block title %}{{ database }}: {{ table }}: {% if count_truncated %}&gt;{{ "{:,}".format(count - 1) }} rows{% elif count or count == 0 %}{{ "{:,}".format(count) }} row{% if count == 1 %}{% else %}s{% endif %}{% endif %}{% if human_description_en %} {{ human_description_en }}{% endif %}{% endblock %}
{% block extra_head %}
{{- super() -}}
@ -48,7 +48,7 @@
{% if count or human_description_en %}
<h3>
{% if count == count_limit + 1 %}&gt;{{ "{:,}".format(count_limit) }} rows
{% if count_truncated %}&gt;{{ "{:,}".format(count - 1) }} rows
{% if allow_execute_sql and query.sql %} <a class="count-sql" style="font-size: 0.8em;" href="{{ urls.database_query(database, count_sql) }}">count all</a>{% endif %}
{% elif count or count == 0 %}{{ "{:,}".format(count) }} row{% if count == 1 %}{% else %}s{% endif %}{% endif %}
{% if human_description_en %}{{ human_description_en }}{% endif %}

2
datasette/views/__init__.py
View file

@ -32,6 +32,8 @@ class Context:
"List of ContextField describing the documented fields of this context"
documented = []
for f in dataclasses.fields(cls):
if f.name.startswith("_"):
continue
from_extra = bool(f.metadata.get("from_extra"))
if from_extra:
help_text = cls._extra_description(f.name)

29
datasette/views/database.py
View file

@ -230,7 +230,6 @@ class DatabaseView(View):
database_actions=database_actions,
show_hidden=request.args.get("_show_hidden"),
editable=True,
count_limit=db.count_limit,
allow_download=datasette.setting("allow_download")
and not db.is_mutable
and not db.is_memory,
@ -267,7 +266,11 @@ class DatabaseContext(Context):
)
path: str = field(metadata={"help": "The URL path to this database"})
size: int = field(metadata={"help": "The size of the database in bytes"})
tables: list = field(metadata={"help": "List of table objects in the database"})
tables: list = field(
metadata={
"help": "List of table objects in the database. Each item includes a ``count_truncated`` key that is true if ``count`` is a capped lower bound rather than an exact total."
}
)
hidden_count: int = field(metadata={"help": "Count of hidden tables"})
views: list = field(metadata={"help": "List of view objects in the database"})
queries: list = field(metadata={"help": "List of stored query objects"})
@ -295,7 +298,6 @@ class DatabaseContext(Context):
editable: bool = field(
metadata={"help": "Boolean indicating if the database is editable"}
)
count_limit: int = field(metadata={"help": "The maximum number of rows to count"})
allow_download: bool = field(
metadata={"help": "Boolean indicating if database download is allowed"}
)
@ -365,7 +367,11 @@ class QueryContext(Context):
save_query_url: str = field(
metadata={"help": "URL to save the current arbitrary SQL as a query"}
)
tables: list = field(metadata={"help": "List of table objects in the database"})
tables: list = field(
metadata={
"help": "List of table objects in the database. Each item includes a ``count_truncated`` key that is true if ``count`` is a capped lower bound rather than an exact total."
}
)
named_parameter_values: dict = field(
metadata={"help": "Dictionary of parameter names/values"}
)
@ -430,6 +436,9 @@ async def get_tables(datasette, request, db, allowed_dict):
"columns": table_columns,
"primary_keys": await db.primary_keys(table),
"count": table_counts[table],
"count_truncated": _table_count_truncated(
datasette, db, table, table_counts[table]
),
"hidden": table in hidden_table_names,
"fts_table": await db.fts_table(table),
"foreign_keys": all_foreign_keys[table],
@ -440,6 +449,18 @@ async def get_tables(datasette, request, db, allowed_dict):
return tables
def _table_count_truncated(datasette, db, table, count):
if count != db.count_limit + 1:
return False
if not db.is_mutable and datasette.inspect_data:
try:
datasette.inspect_data[db.name]["tables"][table]["count"]
return False
except KeyError:
pass
return True
async def database_download(request, datasette):
from datasette.resources import DatabaseResource

33
datasette/views/table.py
View file

@ -113,6 +113,11 @@ class TableContext(Context):
metadata={"help": "True if the data for this page was retrieved without errors"}
)
next: str = field(metadata={"help": "Pagination token for the next page, or None"})
count_truncated: bool = field(
metadata={
"help": "True if ``count`` is a capped lower bound rather than an exact total, because Datasette stopped counting after its configured row-count limit."
}
)
rows: list = field(
metadata={
"help": "The rows for this page, as a list of dictionaries mapping column name to value"
@ -185,11 +190,6 @@ class TableContext(Context):
top_table: callable = field(
metadata={"help": "Async function rendering the top_table plugin slot"}
)
count_limit: int = field(
metadata={
"help": "The maximum number of rows Datasette will count before showing an approximation"
}
)
table_page_data: dict = field(
metadata={"help": "JSON data used by JavaScript on the table page"}
)
@ -1391,7 +1391,6 @@ class TableFragmentView(BaseView):
path_with_replaced_args=path_with_replaced_args,
fix_path=self.ds.urls.path,
settings=self.ds.settings_dict(),
count_limit=resolved.db.count_limit,
),
request=request,
view_name="table",
@ -1843,7 +1842,6 @@ async def table_view_traced(datasette, request):
database=resolved.db.name,
table=resolved.table,
),
count_limit=resolved.db.count_limit,
),
request=request,
view_name="table",
@ -2276,6 +2274,9 @@ async def table_view_data(
data["rows"] = transformed_rows
if context_for_html_hack:
data["count_truncated"] = _count_truncated_for_table_page(
datasette, db, database_name, table_name, count_sql, data.get("count")
)
data.update(extra_context_from_filters)
# filter_columns combine the columns we know are available
# in the table with any additional columns (such as rowid)
@ -2341,6 +2342,24 @@ async def table_view_data(
return data, rows[:page_size], columns, expanded_columns, sql, next_url
def _count_truncated_for_table_page(
datasette, db, database_name, table_name, count_sql, count
):
if count != db.count_limit + 1:
return False
if (
not db.is_mutable
and datasette.inspect_data
and count_sql == f"select count(*) from {table_name} "
):
try:
datasette.inspect_data[database_name]["tables"][table_name]["count"]
return False
except KeyError:
pass
return True
async def _next_value_and_url(
datasette,
db,

4
datasette/views/table_extras.py
View file

@ -127,8 +127,8 @@ class CountExtra(Extra):
pass
if context.count_sql and count is None and not context.nocount:
count_sql_limited = (
f"select count(*) from (select * {context.from_sql} limit 10001)"
count_sql_limited = "select count(*) from (select * {} limit {})".format(
context.from_sql, context.db.count_limit + 1
)
try:
count_rows = list(

13
docs/template_context.rst
View file

@ -100,9 +100,6 @@ The page listing the tables, views and queries in a database, e.g. /fixtures. Re
``attached_databases`` - ``list``
List of names of attached databases
``count_limit`` - ``int``
The maximum number of rows to count
``database`` - ``str``
The name of the database
@ -152,7 +149,7 @@ The page listing the tables, views and queries in a database, e.g. /fixtures. Re
Dictionary mapping table names to their column lists
``tables`` - ``list``
List of table objects in the database
List of table objects in the database. Each item includes a ``count_truncated`` key that is true if ``count`` is a capped lower bound rather than an exact total.
``top_database`` - ``callable``
Callable to render the top_database slot
@ -241,7 +238,7 @@ The page for arbitrary SQL queries (/database/-/query?sql=...) and stored querie
Dictionary of table name to list of column names
``tables`` - ``list``
List of table objects in the database
List of table objects in the database. Each item includes a ``count_truncated`` key that is true if ``count`` is a capped lower bound rather than an exact total.
``top_query`` - ``callable``
Callable to render the top_query slot
@ -280,12 +277,12 @@ Many of these keys are shared with the :ref:`JSON API <json_api>` for this page.
``count`` - ``int``
Total count of rows matching these filters
``count_limit`` - ``int``
The maximum number of rows Datasette will count before showing an approximation
``count_sql`` - ``str``
SQL query used to calculate the total count
``count_truncated`` - ``bool``
True if ``count`` is a capped lower bound rather than an exact total, because Datasette stopped counting after its configured row-count limit.
``custom_table_templates`` - ``list``
Custom template names considered for this table

34
tests/test_template_context.py
View file

@ -21,6 +21,7 @@ def test_documented_fields():
@dataclass
class DemoContext(Context):
name: str = field(metadata={"help": "The name"})
_internal: str = field()
count: int = field(metadata={"help": "How many there are"})
fields = DemoContext.documented_fields()
@ -165,7 +166,11 @@ async def test_template_context_matches_documented_contract(
# The full contract: every key in the rendered template context is
# documented, and every documented key is present in the context
documented = documented_context_keys(page_name)
actual = set(await get_template_context(context_ds, path))
actual = {
key
for key in await get_template_context(context_ds, path)
if not key.startswith("_")
}
undocumented = actual - documented
no_longer_present = documented - actual
assert not undocumented, (
@ -178,6 +183,33 @@ async def test_template_context_matches_documented_contract(
)
@pytest.mark.asyncio
async def test_count_truncated_replaces_count_limit_context_key(context_ds):
db = context_ds.databases["fixtures"]
previous_count_limit = db.count_limit
previous_cached_table_counts = db._cached_table_counts
db.count_limit = 10
db._cached_table_counts = None
try:
table_context = await get_template_context(context_ds, "/fixtures/facetable")
assert table_context["count"] == 11
assert table_context["count_truncated"] is True
assert "count_limit" not in table_context
database_context = await get_template_context(context_ds, "/fixtures")
facetable = next(
table
for table in database_context["tables"]
if table["name"] == "facetable"
)
assert facetable["count"] == 11
assert facetable["count_truncated"] is True
assert "count_limit" not in database_context
finally:
db.count_limit = previous_count_limit
db._cached_table_counts = previous_cached_table_counts
def test_base_context_keys_all_have_docs():
for name, doc in TEMPLATE_BASE_CONTEXT.items():
assert doc, "Base context key {} is missing docs".format(name)