Merge branch 'feature/json-filter'

Cargo.lock

@@ -48,6 +48,7 @@ dependencies = [
  "sailfish",
  "sailfish-compiler",
  "sailfish-macros",
+ "serde_json",
  "trybuild",
 ]
 
@@ -133,6 +134,8 @@ dependencies = [
  "itoap",
  "ryu",
  "sailfish-macros",
+ "serde",
+ "serde_json",
  "version_check",
 ]
 

sailfish-tests/integration-tests/Cargo.toml

@@ -6,9 +6,10 @@ edition = "2018"
 publish = false
 
 [dependencies]
-sailfish = { path = "../../sailfish", default-features = false }
+sailfish = { path = "../../sailfish", default-features = false, features = ["json"] }
 sailfish-macros = { path = "../../sailfish-macros" }
 sailfish-compiler = { path = "../../sailfish-compiler" }
+serde_json = "1.0.53"
 
 [dev-dependencies]
 trybuild = "1.0.28"

sailfish-tests/integration-tests/templates/json-filter.out

@@ -0,0 +1,4 @@
+{
+    "name": "JSON test",
+    "data": {"age":43,"name":"John Doe","phones":["+44 1234567","+44 2345678"]}
+}

sailfish-tests/integration-tests/templates/json-filter.stpl

@@ -0,0 +1,4 @@
+{
+    "name": "JSON test",
+    "data": <%- data | json %>
+}

sailfish-tests/integration-tests/tests/template_once.rs

@@ -307,6 +307,25 @@ struct TruncateFilter;
 fn test_truncate_filter() {
     assert_render("truncate-filter", TruncateFilter);
 }
+#[derive(TemplateOnce)]
+#[template(path = "json-filter.stpl")]
+struct JsonFilter {
+    data: serde_json::Value,
+}
+
+#[test]
+fn test_json_filter() {
+    let data = serde_json::json!({
+        "name": "John Doe",
+        "age": 43,
+        "phones": [
+            "+44 1234567",
+            "+44 2345678"
+        ]
+    });
+
+    assert_render("json-filter", JsonFilter { data });
+}
 
 #[cfg(unix)]
 mod unix {

sailfish/Cargo.toml

@@ -15,11 +15,14 @@ edition = "2018"
 [features]
 default = ["derive", "perf-inline"]
 derive = ["sailfish-macros"]
+json = ["serde", "serde_json"]
 perf-inline = []
 
 [dependencies]
 itoap = "0.1.0"
 ryu = "1.0.4"
+serde = { version = "1.0.111", optional = true }
+serde_json = { version = "1.0.53", optional = true }
 
 [dependencies.sailfish-macros]
 path = "../sailfish-macros"

sailfish/src/runtime/filter.rs

@@ -196,6 +196,74 @@ pub fn truncate<T: Render>(expr: &T, mut limit: usize) -> Truncate<T> {
     Truncate(expr, limit)
 }
 
+cfg_json! {
+    pub struct Json<'a, T>(&'a T);
+
+    impl<'a, T: serde::Serialize> Render for Json<'a, T> {
+        #[inline]
+        fn render(&self, b: &mut Buffer) -> Result<(), RenderError> {
+            struct Writer<'a>(&'a mut Buffer);
+
+            impl<'a> std::io::Write for Writer<'a> {
+                #[inline]
+                fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
+                    let buf = unsafe { std::str::from_utf8_unchecked(buf) };
+                    self.0.push_str(buf);
+                    Ok(buf.len())
+                }
+
+                #[inline]
+                fn write_all(&mut self, buf: &[u8]) -> std::io::Result<()> {
+                    self.write(buf).map(|_| {})
+                }
+
+                #[inline]
+                fn flush(&mut self) -> std::io::Result<()> {
+                    Ok(())
+                }
+            }
+
+            serde_json::to_writer(Writer(b), self.0)
+                .map_err(|e| RenderError::new(&e.to_string()))
+        }
+
+        #[inline]
+        fn render_escaped(&self, b: &mut Buffer) -> Result<(), RenderError> {
+            use super::escape::escape_to_buf;
+
+            struct Writer<'a>(&'a mut Buffer);
+
+            impl<'a> std::io::Write for Writer<'a> {
+                #[inline]
+                fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
+                    let buf = unsafe { std::str::from_utf8_unchecked(buf) };
+                    escape_to_buf(buf, self.0);
+                    Ok(buf.len())
+                }
+
+                #[inline]
+                fn write_all(&mut self, buf: &[u8]) -> std::io::Result<()> {
+                    self.write(buf).map(|_| {})
+                }
+
+                #[inline]
+                fn flush(&mut self) -> std::io::Result<()> {
+                    Ok(())
+                }
+            }
+
+            serde_json::to_writer(Writer(b), self.0)
+                .map_err(|e| RenderError::new(&e.to_string()))
+        }
+    }
+
+    /// Serialize the given data structure as JSON into the buffer
+    #[inline]
+    pub fn json<T: serde::Serialize>(expr: &T) -> Json<T> {
+        Json(expr)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

sailfish/src/runtime/utils.rs

@@ -1,5 +1,15 @@
 use std::ptr;
 
+macro_rules! cfg_json {
+    ($($item:item)*) => {
+        $(
+            #[cfg(feature = "json")]
+            #[cfg_attr(docsrs, doc(cfg(feature = "json")))]
+            $item
+        )*
+    }
+}
+
 #[cfg(sailfish_nightly)]
 macro_rules! likely {
     ($val:expr) => {