add urlencode filter

2 files changed, 23 insertions, 3 deletions

diff --git a/askama_shared/Cargo.toml b/askama_shared/Cargo.toml
index d9faf2f..b8ea481 100644
--- a/askama_shared/Cargo.toml
+++ b/askama_shared/Cargo.toml
@@ -10,7 +10,7 @@ workspace = ".."
 edition = "2018"
 
 [features]
-default = ["config", "humansize", "num-traits"]
+default = ["config", "humansize", "num-traits", "percent-encoding"]
 config = ["serde", "toml"]
 json = ["serde", "serde_json"]
 yaml = ["serde", "serde_yaml"]
@@ -30,6 +30,7 @@ serde_json = { version = "1.0", optional = true }
 serde_yaml = { version = "0.8", optional = true }
 syn = "1"
 toml = { version = "0.5", optional = true }
+percent-encoding = { version = "2.1.0", optional = true }
 
 [package.metadata.docs.rs]
-features = ["config", "humansize", "num-traits", "json", "yaml"]
+features = ["config", "humansize", "num-traits", "json", "yaml", "percent-encoding"]
diff --git a/askama_shared/src/filters/mod.rs b/askama_shared/src/filters/mod.rs
index 1667f40..d5a7c88 100644
--- a/askama_shared/src/filters/mod.rs
+++ b/askama_shared/src/filters/mod.rs
@@ -24,6 +24,8 @@ use askama_escape::{Escaper, MarkupDisplay};
 use humansize::{file_size_opts, FileSize};
 #[cfg(feature = "num_traits")]
 use num_traits::{cast::NumCast, Signed};
+#[cfg(feature = "percent-encoding")]
+use percent_encoding::{utf8_percent_encode, NON_ALPHANUMERIC};
 
 use super::Result;
 
@@ -31,7 +33,7 @@ use super::Result;
 // Askama or should refer to a local `filters` module. It should contain all the
 // filters shipped with Askama, even the optional ones (since optional inclusion
 // in the const vector based on features seems impossible right now).
-pub const BUILT_IN_FILTERS: [&str; 23] = [
+pub const BUILT_IN_FILTERS: [&str; 24] = [
     "abs",
     "capitalize",
     "center",
@@ -52,6 +54,7 @@ pub const BUILT_IN_FILTERS: [&str; 23] = [
     "truncate",
     "upper",
     "uppercase",
+    "urlencode",
     "wordcount",
     "json", // Optional feature; reserve the name anyway
     "yaml", // Optional feature; reserve the name anyway
@@ -102,6 +105,13 @@ pub fn filesizeformat(b: usize) -> Result<String> {
         .map_err(|_| Fmt(fmt::Error))
 }
 
+#[cfg(feature = "percent-encoding")]
+/// Returns the the UTF-8 encoded String of the given input.
+pub fn urlencode(s: &dyn fmt::Display) -> Result<String> {
+    let s = s.to_string();
+    Ok(utf8_percent_encode(&s, NON_ALPHANUMERIC).to_string())
+}
+
 /// Formats arguments according to the specified format
 ///
 /// The first argument to this filter must be a string literal (as in normal
@@ -308,6 +318,15 @@ mod tests {
         assert_eq!(filesizeformat(1024).unwrap(), "1.02 KB");
     }
 
+    #[cfg(feature = "percent-encoding")]
+    #[test]
+    fn test_urlencoding() {
+        assert_eq!(
+            urlencode(&"/path/to/dir with spaces").unwrap(),
+            "%2Fpath%2Fto%2Fdir%20with%20spaces"
+        );
+    }
+
     #[test]
     fn test_linebreaks() {
         assert_eq!(