Add support for include blocks (see #25)

askama_derive/src/generator.rs

@@ -1,4 +1,4 @@
-use parser::{Cond, Expr, Node, Target, WS};
+use parser::{self, Cond, Expr, Node, Target, WS};
 use std::str;
 use std::collections::HashSet;
 use syn;
@@ -27,17 +27,25 @@ struct Generator<'a> {
 
 impl<'a> Generator<'a> {
 
-    fn new() -> Generator<'a> {
+    fn new(locals: HashSet<String>, indent: u8) -> Generator<'a> {
         Generator {
             buf: String::new(),
-            indent: 0,
+            indent: indent,
             start: true,
-            locals: HashSet::new(),
+            locals: locals,
             next_ws: None,
             skip_ws: false,
         }
     }
 
+    fn default() -> Generator<'a> {
+        Self::new(HashSet::new(), 0)
+    }
+
+    fn child(&self) -> Generator<'a> {
+        Self::new(self.locals.clone(), self.indent)
+    }
+
     fn indent(&mut self) {
         self.indent += 1;
     }
@@ -282,6 +290,15 @@ impl<'a> Generator<'a> {
         self.writeln("}");
     }
 
+    fn handle_include(&mut self, ws: &WS, src: &str) {
+        self.prepare_ws(ws);
+        let nodes = parser::parse(&src);
+        let mut gen = self.child();
+        gen.handle(&nodes);
+        self.buf.push_str(&gen.result());
+        self.flush_ws(ws);
+    }
+
     fn handle(&mut self, nodes: &'a [Node]) {
         for n in nodes {
             match *n {
@@ -300,6 +317,9 @@ impl<'a> Generator<'a> {
                 Node::BlockDef(ref ws1, name, ref block_nodes, ref ws2) => {
                     self.write_block_def(ws1, name, block_nodes, ws2);
                 }
+                Node::Include(ref ws, ref src) => {
+                    self.handle_include(ws, src);
+                },
                 Node::Extends(_) => {
                     panic!("no extends or block definition allowed in content");
                 },
@@ -446,7 +466,7 @@ pub fn generate(ast: &syn::DeriveInput, path: &str, mut nodes: Vec<Node>) -> Str
         }
     }
 
-    let mut gen = Generator::new();
+    let mut gen = Generator::default();
     if !blocks.is_empty() {
         if base.is_none() {
             gen.define_trait(path, &block_names);

askama_derive/src/parser.rs

@@ -1,4 +1,5 @@
 use nom::{self, IResult};
+use path;
 use std::str;
 
 #[derive(Debug)]
@@ -31,6 +32,7 @@ pub enum Node<'a> {
     Extends(Expr<'a>),
     BlockDef(WS, &'a str, Vec<Node<'a>>, WS),
     Block(WS, &'a str, WS),
+    Include(WS, String),
 }
 
 pub type Cond<'a> = (WS, Option<Expr<'a>>, Vec<Node<'a>>);
@@ -324,6 +326,25 @@ named!(block_block<Node>, do_parse!(
                     WS(pws2.is_some(), pws2.is_some())))
 ));
 
+named!(block_include<Node>, do_parse!(
+    tag_s!("{%") >>
+    pws: opt!(tag_s!("-")) >>
+    ws!(tag_s!("include")) >>
+    name: ws!(expr_str_lit) >>
+    nws: opt!(tag_s!("-")) >>
+    tag_s!("%}") >>
+    ({
+        let mut src = match name {
+            Expr::StrLit(s) => path::get_template_source(s),
+            _ => panic!("include path must be a string literal"),
+        };
+        if src.ends_with('\n') {
+            let _ = src.pop();
+        }
+        Node::Include(WS(pws.is_some(), nws.is_some()), src)
+    })
+));
+
 named!(block_comment<Node>, do_parse!(
     tag_s!("{#") >>
     take_until_s!("#}") >>
@@ -338,6 +359,7 @@ named!(parse_template<Vec<Node<'a>>>, many0!(alt!(
     block_if |
     block_for |
     block_extends |
+    block_include |
     block_block
 )));