Support anchors.

KmolYuan · Jul 25, 2021 · d353f45 · d353f45
1 parent 183a131
commit d353f45
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Showing 4 changed files with 69 additions and 26 deletions.
diff --git a/README.md b/README.md
@@ -63,7 +63,7 @@ The vertical slides work under the `sub` node of first slide, the attributes are
     - title: Vertical slide 2
 - title: Horizontal slide 2
 ```
-This work supports YAML 1.2 without anchor function.
+This work supports YAML 1.2, and anchor function for specific fields.
 
 ### Layout
 

diff --git a/src/assets/reveal.yaml b/src/assets/reveal.yaml
@@ -277,3 +277,17 @@ footer:
 
           There are also have **markdown** *syntax*!
         ```
+    - title: Anchors
+      doc: |
+        ```yaml
+        $hstack:
+          - &content
+            doc: Content A
+          - *content
+          - *content
+        ```
+      $hstack:
+        - &content
+          doc: Content A
+        - *content
+        - *content
diff --git a/src/loader/content.rs b/src/loader/content.rs
@@ -1,7 +1,7 @@
 use super::*;
 use pulldown_cmark::{html::push_html, CodeBlockKind, Event, Options, Parser, Tag};
 use std::{collections::HashMap, fs::read_to_string};
-use yaml_peg::{Node, Yaml};
+use yaml_peg::{Anchors, Node, Yaml};
 
 const MARKED: Options = Options::from_bits_truncate(
     Options::ENABLE_TABLES.bits()
@@ -36,9 +36,21 @@ fn marked(e: Event) -> Event {
 }
 
 pub(crate) fn md2html(text: &str) -> String {
-    let mut out = String::new();
-    push_html(&mut out, Parser::new_ext(text, MARKED).map(marked));
-    out
+    if text.is_empty() {
+        "".to_string()
+    } else {
+        let mut out = String::new();
+        push_html(&mut out, Parser::new_ext(text, MARKED).map(marked));
+        out
+    }
+}
+
+fn math(text: &str) -> String {
+    if text.is_empty() {
+        "".to_string()
+    } else {
+        format!("\\[{}\\]", text)
+    }
 }
 
 struct FragMap(HashMap<String, HashMap<usize, String>>);
@@ -61,6 +73,9 @@ impl FragMap {
     }
 
     fn fragment(&mut self, tag: &str, inner: &str) -> String {
+        if inner.is_empty() {
+            return "".to_string();
+        }
         let tag = tag.to_string();
         let mut head = String::new();
         let mut end = String::new();
@@ -117,23 +132,25 @@ fn video_block(video: &Node) -> Result<String, Error> {
     Ok(doc)
 }
 
-pub(crate) fn content_block(slide: &Node, frag_count: &mut usize) -> Result<String, Error> {
+pub(crate) fn content_block(
+    slide: &Node,
+    v: &Anchors,
+    frag_count: &mut usize,
+) -> Result<String, Error> {
     let mut doc = String::new();
     let mut frag = FragMap::new(slide, frag_count)?;
-    let mut t = slide.get_default("doc", "", Node::as_str)?;
-    if !t.is_empty() {
-        doc += &frag.fragment("doc", &md2html(t));
+    if let Ok(n) = slide.get("doc") {
+        doc += &frag.fragment("doc", &md2html(n.as_anchor(v).as_str()?));
     }
     if let Ok(n) = slide.get("include") {
-        t = n.as_str()?;
+        let t = n.as_str()?;
         if !t.is_empty() {
             let include = read_to_string(t).map_err(|_| ("read file error", n.pos()))?;
             doc += &frag.fragment("include", &md2html(&include));
         }
     }
-    t = slide.get_default("math", "", Node::as_str)?;
-    if !t.is_empty() {
-        doc += &frag.fragment("math", &format!("\\[{}\\]", t));
+    if let Ok(n) = slide.get("math") {
+        doc += &frag.fragment("math", &math(n.as_anchor(v).as_str()?));
     }
     let media: [(_, fn(&Node) -> Result<String, Error>); 2] =
         [("img", img_block), ("video", video_block)];
@@ -184,7 +201,7 @@ pub(crate) fn content_block(slide: &Node, frag_count: &mut usize) -> Result<Stri
                 ""
             };
             doc += &format!("<div{}{}>", border, head);
-            doc += &content_block(slide, frag_count)?;
+            doc += &content_block(&slide.as_anchor(v), v, frag_count)?;
             doc += "</div>";
         }
         doc += "</div>";

diff --git a/src/loader/mod.rs b/src/loader/mod.rs
@@ -1,6 +1,6 @@
 use self::content::*;
 use std::io::{Error as IoError, ErrorKind};
-use yaml_peg::{indicated_msg, parse, repr::RcRepr, Array, Node};
+use yaml_peg::{indicated_msg, parse, repr::RcRepr, Anchors, Array, Node};
 
 mod content;
 
@@ -65,7 +65,20 @@ impl Background {
     }
 }
 
-fn slide_block(slide: &Node, bg: &Background, first_column: bool) -> Result<String, Error> {
+fn note(text: &str) -> String {
+    if text.is_empty() {
+        "".to_string()
+    } else {
+        format!("<aside class=\"notes\">{}</aside>", text)
+    }
+}
+
+fn slide_block(
+    slide: &Node,
+    v: &Anchors,
+    bg: &Background,
+    first_column: bool,
+) -> Result<String, Error> {
     if slide.as_map()?.is_empty() {
         return Err(Error("empty slide", slide.pos()));
     }
@@ -105,10 +118,9 @@ fn slide_block(slide: &Node, bg: &Background, first_column: bool) -> Result<Stri
             doc += ">";
         }
     }
-    doc += &content_block(slide, &mut 0)?;
-    t = slide.get_default("note", "", Node::as_str)?;
-    if !t.is_empty() {
-        doc += &format!("<aside class=\"notes\">{}</aside>", md2html(&t));
+    doc += &content_block(slide, v, &mut 0)?;
+    if let Ok(n) = slide.get("note") {
+        doc += &note(&md2html(n.as_anchor(v).as_str()?));
     }
     doc += "</section>";
     Ok(doc)
@@ -181,17 +193,18 @@ fn footer_block(meta: &Node) -> Result<String, Error> {
     Ok(doc)
 }
 
-fn load_main(yaml: Array<RcRepr>, mount: &str) -> Result<String, Error> {
+fn load_main(yaml: Array<RcRepr>, v: &Anchors, mount: &str) -> Result<String, Error> {
     let mut title = String::new();
     let meta = &yaml[0];
     let slides = yaml[1].as_array()?;
     let bg = Background::new(meta)?;
     let mut doc = String::new();
     for (i, slide) in slides.iter().enumerate() {
+        let slide = slide.as_anchor(v);
         doc += "<section>";
-        doc += &slide_block(slide, &bg, i == 0)?;
+        doc += &slide_block(&slide, v, &bg, i == 0)?;
         for slide in slide.get_default("sub", &vec![], Node::as_array)? {
-            doc += &slide_block(slide, &bg, false)?;
+            doc += &slide_block(&slide.as_anchor(v), v, &bg, false)?;
         }
         if i == 0 {
             title += slide.get_default("title", "", Node::as_str)?;
@@ -258,15 +271,14 @@ fn load_main(yaml: Array<RcRepr>, mount: &str) -> Result<String, Error> {
 
 /// Load YAML string as HTML.
 pub fn loader(yaml_str: &str, mount: &str) -> Result<String, IoError> {
-    // TODO: anchors
-    let (yaml, _anchor) = parse(yaml_str).map_err(|s| IoError::new(ErrorKind::InvalidData, s))?;
+    let (yaml, anchor) = parse(yaml_str).map_err(|s| IoError::new(ErrorKind::InvalidData, s))?;
     if yaml.len() < 2 {
         return Err(IoError::new(
             ErrorKind::InvalidData,
             "Missing metadata or slides".to_string(),
         ));
     }
-    load_main(yaml, mount).map_err(|Error(name, pos)| {
+    load_main(yaml, &anchor, mount).map_err(|Error(name, pos)| {
         IoError::new(
             ErrorKind::InvalidData,
             format!("{}:\n{}", name, indicated_msg(yaml_str, pos)),