@liteflow/postgraphile-plugin-connection-filter
v2.3.1
Published
Filtering on PostGraphile connections
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postgraphile-plugin-connection-filter
Adds a powerful suite of filtering capabilities to a PostGraphile schema.
Warning: Use of this plugin with the default options may make it astoundingly trivial for a malicious actor (or a well-intentioned application that generates complex GraphQL queries) to overwhelm your database with expensive queries. See the Performance and Security section below for details.
Usage
Requires PostGraphile v4.5.0 or higher.
Install with:
yarn add postgraphile postgraphile-plugin-connection-filter
CLI usage via --append-plugins
:
postgraphile --append-plugins postgraphile-plugin-connection-filter -c postgres://localhost/my_db ...
Library usage via appendPlugins
:
import ConnectionFilterPlugin from "postgraphile-plugin-connection-filter";
// or: const ConnectionFilterPlugin = require("postgraphile-plugin-connection-filter");
const middleware = postgraphile(DATABASE_URL, SCHEMAS, {
appendPlugins: [ConnectionFilterPlugin],
});
Performance and Security
By default, this plugin:
- Exposes a large number of filter operators, including some that can perform expensive pattern matching.
- Allows filtering on computed columns, which can result in expensive operations.
- Allows filtering on functions that return
setof
, which can result in expensive operations. - Allows filtering on List fields (Postgres arrays), which can result in expensive operations.
To protect your server, you can:
- Use the
connectionFilterAllowedFieldTypes
andconnectionFilterAllowedOperators
options to limit the filterable fields and operators exposed through GraphQL. - Set
connectionFilterComputedColumns: false
to prevent filtering on computed columns. - Set
connectionFilterSetofFunctions: false
to prevent filtering on functions that returnsetof
. - Set
connectionFilterArrays: false
to prevent filtering on List fields (Postgres arrays).
Also see the Production Considerations page of the official PostGraphile docs, which discusses query whitelisting.
Features
This plugin supports filtering on almost all PostgreSQL types, including complex types such as domains, ranges, arrays, and composite types. For details on the specific operators supported for each type, see docs/operators.md.
See also:
- @graphile/pg-aggregates - integrates with this plugin to enable powerful aggregate filtering
- postgraphile-plugin-connection-filter-postgis - adds PostGIS functions and operators for filtering on
geography
/geometry
columns - postgraphile-plugin-fulltext-filter - adds a full text search operator for filtering on
tsvector
columns - postgraphile-plugin-unaccented-text-search-filter - adds unaccent text search operators
Handling null
and empty objects
By default, this plugin will throw an error when null
literals or empty objects ({}
) are included in filter
input objects. This prevents queries with ambiguous semantics such as filter: { field: null }
and filter: { field: { equalTo: null } }
from returning unexpected results. For background on this decision, see https://github.com/graphile-contrib/postgraphile-plugin-connection-filter/issues/58.
To allow null
and {}
in inputs, use the connectionFilterAllowNullInput
and connectionFilterAllowEmptyObjectInput
options documented under Plugin Options. Please note that even with connectionFilterAllowNullInput
enabled, null
is never interpreted as a SQL NULL
; fields with null
values are simply ignored when resolving the query.
Plugin Options
When using PostGraphile as a library, the following plugin options can be passed via graphileBuildOptions
:
connectionFilterAllowedOperators
Restrict filtering to specific operators:
postgraphile(pgConfig, schema, {
graphileBuildOptions: {
connectionFilterAllowedOperators: [
"isNull",
"equalTo",
"notEqualTo",
"distinctFrom",
"notDistinctFrom",
"lessThan",
"lessThanOrEqualTo",
"greaterThan",
"greaterThanOrEqualTo",
"in",
"notIn",
],
},
});
connectionFilterAllowedFieldTypes
Restrict filtering to specific field types:
postgraphile(pgConfig, schema, {
graphileBuildOptions: {
connectionFilterAllowedFieldTypes: ["String", "Int"],
},
});
The available field types will depend on your database schema.
connectionFilterArrays
Enable/disable filtering on PostgreSQL arrays:
postgraphile(pgConfig, schema, {
graphileBuildOptions: {
connectionFilterArrays: false, // default: true
},
});
connectionFilterComputedColumns
Enable/disable filtering by computed columns:
postgraphile(pgConfig, schema, {
graphileBuildOptions: {
connectionFilterComputedColumns: false, // default: true
},
});
Consider setting this to false
and using @filterable
smart comments to selectively enable filtering:
create function app_public.foo_computed(foo app_public.foo)
returns ... as $$ ... $$ language sql stable;
comment on function app_public.foo_computed(foo app_public.foo) is E'@filterable';
connectionFilterOperatorNames
Use alternative names (e.g. eq
, ne
) for operators:
postgraphile(pgConfig, schema, {
graphileBuildOptions: {
connectionFilterOperatorNames: {
equalTo: "eq",
notEqualTo: "ne",
},
},
});
connectionFilterRelations
Enable/disable filtering on related fields:
postgraphile(pgConfig, schema, {
graphileBuildOptions: {
connectionFilterRelations: true, // default: false
},
});
connectionFilterSetofFunctions
Enable/disable filtering on functions that return setof
:
postgraphile(pgConfig, schema, {
graphileBuildOptions: {
connectionFilterSetofFunctions: false, // default: true
},
});
Consider setting this to false
and using @filterable
smart comments to selectively enable filtering:
create function app_public.some_foos()
returns setof ... as $$ ... $$ language sql stable;
comment on function app_public.some_foos() is E'@filterable';
connectionFilterLogicalOperators
Enable/disable filtering with logical operators (and
/or
/not
):
postgraphile(pgConfig, schema, {
graphileBuildOptions: {
connectionFilterLogicalOperators: false, // default: true
},
});
connectionFilterAllowNullInput
Allow/forbid null
literals in input:
postgraphile(pgConfig, schema, {
graphileBuildOptions: {
connectionFilterAllowNullInput: true, // default: false
},
});
When false
, passing null
as a field value will throw an error.
When true
, passing null
as a field value is equivalent to omitting the field.
connectionFilterAllowEmptyObjectInput
Allow/forbid empty objects ({}
) in input:
postgraphile(pgConfig, schema, {
graphileBuildOptions: {
connectionFilterAllowEmptyObjectInput: true, // default: false
},
});
When false
, passing {}
as a field value will throw an error.
When true
, passing {}
as a field value is equivalent to omitting the field.
connectionFilterUseListInflectors
When building the "many" relationship filters, if this option is set true
then we will use the "list" field names rather than the "connection" field
names when naming the fields in the filter input. This would be desired if you
have simpleCollection
set to "only"
or "both"
and you've simplified your
inflection to omit the -list
suffix, e.g. using
@graphile-contrib/pg-simplify-inflector
's pgOmitListSuffix
option. Use this
if you see Connection
added to your filter field names.
postgraphile(pgConfig, schema, {
graphileBuildOptions: {
connectionFilterUseListInflectors: true, // default: false
},
});
Examples
query {
allPosts(filter: {
createdAt: { greaterThan: "2021-01-01" }
}) {
...
}
}
For an extensive set of examples, see docs/examples.md.
Development
To establish a test environment, create an empty PostgreSQL database with C collation (required for consistent ordering of strings) and set a TEST_DATABASE_URL
environment variable with your database connection string.
createdb graphile_test_c --template template0 --lc-collate C
export TEST_DATABASE_URL=postgres://localhost:5432/graphile_test_c
yarn
yarn test