Document mechanism for user-defined filters (fixes #102)

2 files changed, 9 insertions, 3 deletions

diff --git a/askama/src/lib.rs b/askama/src/lib.rs
index 7f14b3d..613c8d9 100644
--- a/askama/src/lib.rs
+++ b/askama/src/lib.rs
@@ -79,8 +79,13 @@
 //! characters from the value obtained by accessing the `name` field,
 //! and print the resulting string as a Rust literal.
 //!
-//! Consult the [filters module documentation](filters/index.html) for a list
-//! of available filters.
+//! The built-in filters are documented as part of the
+//! [filters module documentation](filters/index.html).
+//!
+//! To define your own filters, simply have a module named `filters` in
+//! scope of the context deriving a `Template` `impl`. Any filter names
+//! that are not part of the built-in filters will be referenced through
+//! the `filters::` prefix.
 //!
 //! ## Whitespace control
 //!
diff --git a/askama_shared/src/filters/mod.rs b/askama_shared/src/filters/mod.rs
index e4caccd..181e27b 100644
--- a/askama_shared/src/filters/mod.rs
+++ b/askama_shared/src/filters/mod.rs
@@ -1,7 +1,8 @@
 //! Module for built-in filter functions
 //!
 //! Contains all the built-in filter functions for use in templates.
-//! Currently, there is no way to define filters outside this module.
+//! You can define your own filters; for more information,
+//! see the top-level crate documentation.
 
 #[cfg(feature = "serde-json")]
 mod json;