use std::borrow::Cow::Owned; use pulldown_cmark as cmark; use self::cmark::{Parser, Event, Tag, Options, OPTION_ENABLE_TABLES, OPTION_ENABLE_FOOTNOTES}; use slug::slugify; use syntect::easy::HighlightLines; use syntect::html::{start_coloured_html_snippet, styles_to_coloured_html, IncludeBackground}; use tera::{Context as TeraContext}; use errors::Result; use utils::site::resolve_internal_link; use front_matter::InsertAnchor; use context::Context; use highlighting::{SYNTAX_SET, THEME_SET}; use short_code::{SHORTCODE_RE, ShortCode, parse_shortcode, render_simple_shortcode}; use table_of_contents::{TempHeader, Header, make_table_of_contents}; pub fn markdown_to_html(content: &str, context: &Context) -> Result<(String, Vec
)> { // We try to be smart about highlighting code as it can be time-consuming // If the global config disables it, then we do nothing. However, // if we see a code block in the content, we assume that this page needs // to be highlighted. It could potentially have false positive if the content // has ``` in it but that seems kind of unlikely let should_highlight = if context.highlight_code { content.contains("```") } else { false }; // Set while parsing let mut error = None; let mut highlighter: Option = None; let mut shortcode_block = None; // shortcodes live outside of paragraph so we need to ensure we don't close // a paragraph that has already been closed let mut added_shortcode = false; // Don't transform things that look like shortcodes in code blocks let mut in_code_block = false; // If we get text in header, we need to insert the id and a anchor let mut in_header = false; // pulldown_cmark can send several text events for a title if there are markdown // specific characters like `!` in them. We only want to insert the anchor the first time let mut header_already_inserted = false; let mut anchors: Vec = vec![]; // the rendered html let mut html = String::new(); // We might have cases where the slug is already present in our list of anchor // for example an article could have several titles named Example // We add a counter after the slug if the slug is already present, which // means we will have example, example-1, example-2 etc fn find_anchor(anchors: &[String], name: String, level: u8) -> String { if level == 0 && !anchors.contains(&name) { return name.to_string(); } let new_anchor = format!("{}-{}", name, level + 1); if !anchors.contains(&new_anchor) { return new_anchor; } find_anchor(anchors, name, level + 1) } let mut headers = vec![]; // Defaults to a 0 level so not a real header // It should be an Option ideally but not worth the hassle to update let mut temp_header = TempHeader::default(); let mut opts = Options::empty(); opts.insert(OPTION_ENABLE_TABLES); opts.insert(OPTION_ENABLE_FOOTNOTES); { let parser = Parser::new_ext(content, opts).map(|event| match event { Event::Text(text) => { // if we are in the middle of a code block if let Some(ref mut highlighter) = highlighter { let highlighted = &highlighter.highlight(&text); let html = styles_to_coloured_html(highlighted, IncludeBackground::Yes); return Event::Html(Owned(html)); } if in_code_block { return Event::Text(text); } // Shortcode without body if shortcode_block.is_none() && text.starts_with("{{") && text.ends_with("}}") && SHORTCODE_RE.is_match(&text) { let (name, args) = parse_shortcode(&text); added_shortcode = true; match render_simple_shortcode(context.tera, &name, &args) { Ok(s) => return Event::Html(Owned(format!("

{}", s))), Err(e) => { error = Some(e); return Event::Html(Owned("".to_string())); } } // non-matching will be returned normally below } // Shortcode with a body if shortcode_block.is_none() && text.starts_with("{%") && text.ends_with("%}") { if SHORTCODE_RE.is_match(&text) { let (name, args) = parse_shortcode(&text); shortcode_block = Some(ShortCode::new(&name, args)); } // Don't return anything return Event::Text(Owned("".to_string())); } // If we have some text while in a shortcode, it's either the body // or the end tag if shortcode_block.is_some() { if let Some(ref mut shortcode) = shortcode_block { if text.trim() == "{% end %}" { added_shortcode = true; match shortcode.render(context.tera) { Ok(s) => return Event::Html(Owned(format!("

{}", s))), Err(e) => { error = Some(e); return Event::Html(Owned("".to_string())); } } } else { shortcode.append(&text); return Event::Html(Owned("".to_string())); } } } if in_header { if header_already_inserted { return Event::Text(text); } let id = find_anchor(&anchors, slugify(&text), 0); anchors.push(id.clone()); let anchor_link = if context.should_insert_anchor() { let mut c = TeraContext::new(); c.add("id", &id); context.tera.render("anchor-link.html", &c).unwrap() } else { String::new() }; // update the header and add it to the list temp_header.id = id.clone(); temp_header.title = text.clone().into_owned(); temp_header.permalink = format!("{}#{}", context.current_page_permalink, id); headers.push(temp_header.clone()); temp_header = TempHeader::default(); header_already_inserted = true; let event = match context.insert_anchor { InsertAnchor::Left => Event::Html(Owned(format!(r#"id="{}">{}{}"#, id, anchor_link, text))), InsertAnchor::Right => Event::Html(Owned(format!(r#"id="{}">{}{}"#, id, text, anchor_link))), InsertAnchor::None => Event::Html(Owned(format!(r#"id="{}">{}"#, id, text))) }; return event; } // Business as usual Event::Text(text) }, Event::Start(Tag::CodeBlock(ref info)) => { in_code_block = true; if !should_highlight { return Event::Html(Owned("
".to_owned()));
                }
                let theme = &THEME_SET.themes[&context.highlight_theme];
                highlighter = SYNTAX_SET.with(|ss| {
                    let syntax = info
                        .split(' ')
                        .next()
                        .and_then(|lang| ss.find_syntax_by_token(lang))
                        .unwrap_or_else(|| ss.find_syntax_plain_text());
                    Some(HighlightLines::new(syntax, theme))
                });
                let snippet = start_coloured_html_snippet(theme);
                Event::Html(Owned(snippet))
            },
            Event::End(Tag::CodeBlock(_)) => {
                in_code_block = false;
                if !should_highlight{
                    return Event::Html(Owned("
\n".to_owned())) } // reset highlight and close the code block highlighter = None; Event::Html(Owned("".to_owned())) }, // Need to handle relative links Event::Start(Tag::Link(ref link, ref title)) => { if in_header { return Event::Html(Owned("".to_owned())); } if link.starts_with("./") { match resolve_internal_link(link, context.permalinks) { Ok(url) => { return Event::Start(Tag::Link(Owned(url), title.clone())); }, Err(_) => { error = Some(format!("Relative link {} not found.", link).into()); return Event::Html(Owned("".to_string())); } }; } Event::Start(Tag::Link(link.clone(), title.clone())) }, Event::End(Tag::Link(_, _)) => { if in_header { return Event::Html(Owned("".to_owned())); } event } // need to know when we are in a code block to disable shortcodes in them Event::Start(Tag::Code) => { in_code_block = true; event }, Event::End(Tag::Code) => { in_code_block = false; event }, Event::Start(Tag::Header(num)) => { in_header = true; temp_header = TempHeader::new(num); // ugly eh Event::Html(Owned(format!(" { in_header = false; header_already_inserted = false; event }, // If we added shortcodes, don't close a paragraph since there's none Event::End(Tag::Paragraph) => { if added_shortcode { added_shortcode = false; return Event::Html(Owned("".to_owned())); } event }, // Ignore softbreaks inside shortcodes Event::SoftBreak => { if shortcode_block.is_some() { return Event::Html(Owned("".to_owned())); } event }, _ => { // println!("event = {:?}", event); event }, }); cmark::html::push_html(&mut html, parser); } match error { Some(e) => Err(e), None => Ok((html.replace("

", ""), make_table_of_contents(headers))), } }