docgen: Support pikchr diagrams

Signed-off-by: Daniel Silverstone <dsilvers@digital-scurf.org>

3 files changed, 33 insertions, 2 deletions

diff --git a/src/doc.rs b/src/doc.rs
index 89f626a..64f4648 100644
--- a/src/doc.rs
+++ b/src/doc.rs
@@ -19,7 +19,7 @@ use pandoc_ast::{MutVisitor, Pandoc};
 
 /// The set of known (special) classes which subplot will always recognise
 /// as being valid.
-static SPECIAL_CLASSES: &[&str] = &["scenario", "file", "dot", "plantuml", "roadmap"];
+static SPECIAL_CLASSES: &[&str] = &["scenario", "file", "dot", "pikchr", "plantuml", "roadmap"];
 
 /// The set of known (file-type) classes which subplot will always recognise
 /// as being valid.
diff --git a/src/typeset.rs b/src/typeset.rs
index 40cbef6..2904b6a 100644
--- a/src/typeset.rs
+++ b/src/typeset.rs
@@ -4,7 +4,7 @@ use crate::PartialStep;
 use crate::ScenarioStep;
 use crate::StepKind;
 use crate::SubplotError;
-use crate::{DotMarkup, GraphMarkup, PlantumlMarkup};
+use crate::{DotMarkup, GraphMarkup, PikchrMarkup, PlantumlMarkup};
 
 use pandoc_ast::Attr;
 use pandoc_ast::Block;
@@ -133,6 +133,23 @@ pub fn link_as_note(attr: Attr, text: Vec<Inline>, target: Target) -> Inline {
     Inline::Span(attr, text)
 }
 
+/// Take a pikchr graph, render it as SVG, and return an AST block element.
+///
+/// The `Block` will contain the SVG data.  This allows the graph to be
+/// rendered without referencing external entities.
+///
+/// If the code block which contained the pikchr contains other classes, they
+/// can be added to the SVG for use in later typesetting etc.
+pub fn pikchr_to_block(pikchr: &str, class: Option<&str>) -> Block {
+    match PikchrMarkup::new(pikchr, class).as_svg() {
+        Ok(svg) => typeset_svg(svg),
+        Err(err) => {
+            eprintln!("pikchr render failed: {}", err);
+            error(err)
+        }
+    }
+}
+
 // Take a dot graph, render it as SVG, and return an AST Block
 // element. The Block will contain the SVG data. This allows the graph
 // to be rendered without referending external entities.
diff --git a/src/visitor/typesetting.rs b/src/visitor/typesetting.rs
index deffcd9..f59f81d 100644
--- a/src/visitor/typesetting.rs
+++ b/src/visitor/typesetting.rs
@@ -39,6 +39,20 @@ impl<'a> MutVisitor for TypesettingVisitor<'a> {
                         *block = typeset::plantuml_to_block(s)
                     } else if is_class(attr, "roadmap") {
                         *block = typeset::roadmap_to_block(s)
+                    } else if is_class(attr, "pikchr") {
+                        let other_classes: Vec<_> = attr
+                            .1
+                            .iter()
+                            .map(String::as_str)
+                            .filter(|s| *s != "pikchr")
+                            .collect();
+                        let class = if other_classes.is_empty() {
+                            None
+                        } else {
+                            Some(other_classes.join(" "))
+                        };
+                        let class = class.as_deref();
+                        *block = typeset::pikchr_to_block(s, class)
                     }
                 }
                 _ => {