tree update!

content/_treehouse/404.tree

@@ -0,0 +1,10 @@
+%% title = "404"
+
+% id = "404"
+- # 404
+
+    % id = "01HMF8KQ997F1ZTEGDNAE2S6F1"
+    - seems like the page you're looking for isn't here.
+
+    % id = "01HMF8KQ99XNMEP67NE3QH5698"
+    - care to go [back to the index][branch:treehouse]?

content/_treehouse/b.tree

@@ -0,0 +1,21 @@
+%% title = "GET /b"
+
+% id = "b"
+- # GET /b?<span class="http-request-parameter">branch</span>
+
+<style>
+.http-request-parameter { opacity: 80%; --recursive-wght: 700; }
+</style>
+
+    % id = "01HMF8KQ990KC8Q08XYSKTV4TQ"
+    - this endpoint takes you to the <span class="http-request-parameter">branch</span> with the given ID
+
+        % id = "01HMF8KQ99VBWQSG1Y8NDTM8QA"
+        - it also includes proper OpenGraph metadata for the page, unlike the raw .html files.
+        therefore it's used for permalinks (those on the far right side of the branch →)
+
+    % id = "01HMF8KQ99KWR1K9QHKPYY2K15"
+    + c'mon, [give it a whirl](/b?the-end-is-never)
+
+        % id = "01HMF8KQ99WX9P6D05T5VYBSKK"
+        - <https://www.youtube.com/watch?v=8Kban1IOQ4M>

content/index.tree

@@ -1,3 +1,5 @@
+%% title = "liquidex's treehouse"
+
 % id = "treehouse"
 - # liquidex's treehouse
 <span class="oops-you-seem-to-have-gotten-stuck">

crates/treehouse-format/src/ast.rs

@@ -7,11 +7,14 @@ use crate::{
 
 #[derive(Debug, Clone)]
 pub struct Roots {
+    pub attributes: Option<Attributes>,
     pub branches: Vec<Branch>,
 }
 
 impl Roots {
     pub fn parse(parser: &mut Parser) -> Result<Self, ParseError> {
+        let attributes = parser.top_level_attributes()?;
+
         let mut branches = vec![];
         while let Some((branch, indent_level)) = Branch::parse_with_indent_level(parser)? {
             if indent_level != 0 {
@@ -19,7 +22,10 @@ impl Roots {
             }
             branches.push(branch);
         }
-        Ok(Self { branches })
+        Ok(Self {
+            attributes,
+            branches,
+        })
     }
 }
 

crates/treehouse-format/src/pull.rs

@@ -151,6 +151,34 @@ impl<'a> Parser<'a> {
         Ok(())
     }
 
+    pub fn top_level_attributes(&mut self) -> Result<Option<Attributes>, ParseError> {
+        let start = self.position;
+        match self.current() {
+            Some('%') => {
+                let after_one_percent = self.position;
+                self.advance();
+                if self.current() == Some('%') {
+                    self.advance();
+                    let after_two_percent = self.position;
+                    self.eat_indented_lines_until(
+                        0,
+                        |c| c == '-' || c == '+' || c == '%',
+                        AllowCodeBlocks::No,
+                    )?;
+                    let end = self.position;
+                    Ok(Some(Attributes {
+                        percent: start..after_two_percent,
+                        data: after_two_percent..end,
+                    }))
+                } else {
+                    self.position = after_one_percent;
+                    Ok(None)
+                }
+            }
+            _ => Ok(None),
+        }
+    }
+
     pub fn next_branch(&mut self) -> Result<Option<BranchEvent>, ParseError> {
         if self.current().is_none() {
             return Ok(None);

crates/treehouse/src/cli/fix.rs

@@ -4,7 +4,7 @@ use anyhow::Context;
 use treehouse_format::ast::Branch;
 use walkdir::WalkDir;
 
-use crate::state::{FileId, Treehouse};
+use crate::state::{FileId, Source, Treehouse};
 
 use super::{
     parse::{self, parse_toml_with_diagnostics, parse_tree_with_diagnostics},
@@ -106,7 +106,7 @@ pub fn fix_file(
     file_id: FileId,
 ) -> Result<String, parse::ErrorsEmitted> {
     parse_tree_with_diagnostics(treehouse, file_id).map(|roots| {
-        let mut source = treehouse.source(file_id).to_owned();
+        let mut source = treehouse.source(file_id).input().to_owned();
         let mut state = State::default();
 
         for branch in &roots.branches {
@@ -130,14 +130,14 @@ pub fn fix_file_cli(fix_args: FixArgs) -> anyhow::Result<()> {
     let file = std::fs::read_to_string(&fix_args.file).context("cannot read file to fix")?;
 
     let mut treehouse = Treehouse::new();
-    let file_id = treehouse.add_file(utf8_filename, None, file);
+    let file_id = treehouse.add_file(utf8_filename, Source::Other(file));
 
     if let Ok(fixed) = fix_file(&mut treehouse, file_id) {
         if fix_args.apply {
             // Try to write the backup first. If writing that fails, bail out without overwriting
             // the source file.
             if let Some(backup_path) = fix_args.backup {
-                std::fs::write(backup_path, treehouse.source(file_id))
+                std::fs::write(backup_path, treehouse.source(file_id).input())
                     .context("cannot write backup; original file will not be overwritten")?;
             }
             std::fs::write(&fix_args.file, fixed).context("cannot overwrite original file")?;
@@ -160,10 +160,10 @@ pub fn fix_all_cli(fix_all_args: FixAllArgs, paths: &Paths<'_>) -> anyhow::Resul
             let utf8_filename = entry.path().to_string_lossy();
 
             let mut treehouse = Treehouse::new();
-            let file_id = treehouse.add_file(utf8_filename.into_owned(), None, file);
+            let file_id = treehouse.add_file(utf8_filename.into_owned(), Source::Other(file));
 
             if let Ok(fixed) = fix_file(&mut treehouse, file_id) {
-                if fixed != treehouse.source(file_id) {
+                if fixed != treehouse.source(file_id).input() {
                     if fix_all_args.apply {
                         println!("fixing: {:?}", entry.path());
                         std::fs::write(entry.path(), fixed).with_context(|| {

crates/treehouse/src/cli/generate.rs

@@ -5,17 +5,14 @@ use std::{
 };
 
 use anyhow::{bail, Context};
-use axum::Router;
 use codespan_reporting::{
     diagnostic::{Diagnostic, Label, LabelStyle, Severity},
     files::Files as _,
 };
 use copy_dir::copy_dir;
 use handlebars::Handlebars;
-use log::{debug, info};
+use log::{debug, error, info};
 use serde::Serialize;
-use tower_http::services::ServeDir;
-use tower_livereload::LiveReloadLayer;
 use walkdir::WalkDir;
 
 use crate::{
@@ -26,6 +23,7 @@ use crate::{
         navmap::{build_navigation_map, NavigationMap},
         tree::branches_to_html,
     },
+    state::Source,
     tree::SemaRoots,
 };
 
@@ -63,7 +61,8 @@ impl Generator {
     ) -> anyhow::Result<FileId> {
         let source = std::fs::read_to_string(path)
             .with_context(|| format!("cannot read template file {path:?}"))?;
-        let file_id = treehouse.add_file(path.to_string_lossy().into_owned(), None, source);
+        let file_id =
+            treehouse.add_file(path.to_string_lossy().into_owned(), Source::Other(source));
         let source = treehouse.source(file_id);
         if let Err(error) = handlebars.register_template_string(name, source) {
             Self::wrangle_handlebars_error_into_diagnostic(
@@ -136,9 +135,17 @@ impl Generator {
                     continue;
                 }
             };
-            let tree_path = tree_path.with_extension("").to_string_lossy().replace('\\', "/");
-            let file_id =
-                treehouse.add_file(utf8_filename.into_owned(), Some(tree_path.clone()), source);
+            let tree_path = tree_path
+                .with_extension("")
+                .to_string_lossy()
+                .replace('\\', "/");
+            let file_id = treehouse.add_file(
+                utf8_filename.into_owned(),
+                Source::Tree {
+                    input: source,
+                    tree_path: tree_path.clone(),
+                },
+            );
 
             if let Ok(roots) = parse_tree_with_diagnostics(&mut treehouse, file_id) {
                 let roots = SemaRoots::from_roots(&mut treehouse, file_id, roots);
@@ -186,20 +193,30 @@ impl Generator {
                 parsed_tree.file_id,
                 &roots.branches,
             );
-            treehouse.roots.insert(parsed_tree.tree_path, roots);
+
+            #[derive(Serialize)]
+            pub struct Page {
+                pub title: String,
+                pub breadcrumbs: String,
+                pub tree: String,
+            }
 
             #[derive(Serialize)]
             pub struct TemplateData<'a> {
                 pub config: &'a Config,
-                pub breadcrumbs: String,
-                pub tree: String,
+                pub page: Page,
             }
             let template_data = TemplateData {
                 config,
+                page: Page {
+                    title: roots.attributes.title.clone(),
                     breadcrumbs,
                     tree,
+                },
             };
 
+            treehouse.roots.insert(parsed_tree.tree_path, roots);
+
             let templated_html = match handlebars.render("tree", &template_data) {
                 Ok(html) => html,
                 Err(error) => {
@@ -227,7 +244,7 @@ impl Generator {
     }
 }
 
-pub fn regenerate(paths: &Paths<'_>) -> anyhow::Result<()> {
+pub fn generate(paths: &Paths<'_>) -> anyhow::Result<Treehouse> {
     let start = Instant::now();
 
     info!("loading config");
@@ -268,26 +285,19 @@ pub fn regenerate(paths: &Paths<'_>) -> anyhow::Result<()> {
     let duration = start.elapsed();
     info!("generation done in {duration:?}");
 
-    Ok(())
+    if !treehouse.has_errors() {
+        Ok(treehouse)
+    } else {
+        bail!("generation errors occurred; diagnostics were emitted with detailed descriptions");
+    }
 }
 
-pub fn regenerate_or_report_error(paths: &Paths<'_>) {
+pub fn regenerate_or_report_error(paths: &Paths<'_>) -> anyhow::Result<Treehouse> {
     info!("regenerating site content");
 
-    match regenerate(paths) {
-        Ok(_) => (),
-        Err(error) => eprintln!("error: {error:?}"),
+    let result = generate(paths);
+    if let Err(e) = &result {
+        error!("{e:?}");
     }
-}
-
-pub async fn web_server(port: u16) -> anyhow::Result<()> {
-    let app = Router::new().nest_service("/", ServeDir::new("target/site"));
-
-    #[cfg(debug_assertions)]
-    let app = app.layer(LiveReloadLayer::new());
-
-    info!("serving on port {port}");
-    Ok(axum::Server::bind(&([0, 0, 0, 0], port).into())
-        .serve(app.into_make_service())
-        .await?)
+    result
 }

crates/treehouse/src/cli/mod.rs

@@ -1,6 +1,7 @@
 pub mod fix;
 pub mod generate;
 mod parse;
+pub mod serve;
 
 use std::path::{Path, PathBuf};
 
@@ -24,14 +25,21 @@ pub enum Command {
     ///
     /// By default only prints which files would be changed. To apply the changes, use `--apply`.
     FixAll(#[clap(flatten)] FixAllArgs),
+
+    /// `generate` and start a treehouse server.
+    ///
+    /// The server uses the generated files and provides extra functionality on top, handling
+    Serve {
+        #[clap(flatten)]
+        generate: GenerateArgs,
+
+        #[clap(flatten)]
+        serve: ServeArgs,
+    },
 }
 
 #[derive(Args)]
-pub struct GenerateArgs {
-    /// Start a web server serving the static files on the given port. Useful with `cargo watch`.
-    #[clap(short, long)]
-    pub serve: Option<u16>,
-}
+pub struct GenerateArgs {}
 
 #[derive(Args)]
 pub struct FixArgs {
@@ -57,6 +65,13 @@ pub struct FixAllArgs {
     pub apply: bool,
 }
 
+#[derive(Args)]
+pub struct ServeArgs {
+    /// The port under which to serve the treehouse.
+    #[clap(short, long, default_value_t = 8080)]
+    pub port: u16,
+}
+
 #[derive(Debug, Clone, Copy)]
 pub struct Paths<'a> {
     pub target_dir: &'a Path,

crates/treehouse/src/cli/parse.rs

@@ -11,7 +11,7 @@ pub fn parse_tree_with_diagnostics(
     treehouse: &mut Treehouse,
     file_id: FileId,
 ) -> Result<Roots, ErrorsEmitted> {
-    let input = treehouse.source(file_id);
+    let input = &treehouse.source(file_id).input();
     Roots::parse(&mut treehouse_format::pull::Parser { input, position: 0 }).map_err(|error| {
         treehouse.diagnostics.push(Diagnostic {
             severity: Severity::Error,
@@ -34,7 +34,7 @@ pub fn parse_toml_with_diagnostics(
     file_id: FileId,
     range: Range<usize>,
 ) -> Result<toml_edit::Document, ErrorsEmitted> {
-    let input = &treehouse.source(file_id)[range.clone()];
+    let input = &treehouse.source(file_id).input()[range.clone()];
     toml_edit::Document::from_str(input).map_err(|error| {
         treehouse
             .diagnostics

crates/treehouse/src/cli/serve.rs

@@ -0,0 +1,86 @@
+use std::{path::PathBuf, sync::Arc};
+
+use anyhow::Context;
+use axum::{
+    extract::{RawQuery, State},
+    response::Html,
+    routing::get,
+    Router,
+};
+use log::{error, info};
+use pulldown_cmark::escape::escape_html;
+use tower_http::services::ServeDir;
+
+use crate::state::{Source, Treehouse};
+
+use super::Paths;
+
+struct SystemPages {
+    four_oh_four: String,
+    b_docs: String,
+}
+
+struct Server {
+    treehouse: Treehouse,
+    target_dir: PathBuf,
+    system_pages: SystemPages,
+}
+
+pub async fn serve(treehouse: Treehouse, paths: &Paths<'_>, port: u16) -> anyhow::Result<()> {
+    let app = Router::new()
+        .nest_service("/", ServeDir::new(paths.target_dir))
+        .route("/b", get(branch))
+        .with_state(Arc::new(Server {
+            treehouse,
+            target_dir: paths.target_dir.to_owned(),
+            system_pages: SystemPages {
+                four_oh_four: std::fs::read_to_string(paths.target_dir.join("_treehouse/404.html"))
+                    .context("cannot read 404 page")?,
+                b_docs: std::fs::read_to_string(paths.target_dir.join("_treehouse/b.html"))
+                    .context("cannot read /b documentation page")?,
+            },
+        }));
+
+    #[cfg(debug_assertions)]
+    let app = app.layer(tower_livereload::LiveReloadLayer::new());
+
+    info!("serving on port {port}");
+    Ok(axum::Server::bind(&([0, 0, 0, 0], port).into())
+        .serve(app.into_make_service())
+        .await?)
+}
+
+async fn branch(RawQuery(named_id): RawQuery, State(state): State<Arc<Server>>) -> Html<String> {
+    if let Some(named_id) = named_id {
+        if let Some(&branch_id) = state.treehouse.branches_by_named_id.get(&named_id) {
+            let branch = state.treehouse.tree.branch(branch_id);
+            if let Source::Tree { input, tree_path } = state.treehouse.source(branch.file_id) {
+                let file_path = state.target_dir.join(format!("{tree_path}.html"));
+                match std::fs::read_to_string(&file_path) {
+                    Ok(content) => {
+                        let branch_markdown_content = input[branch.content.clone()].trim();
+                        let mut per_page_metadata =
+                            String::from("<meta property=\"og:description\" content=\"");
+                        escape_html(&mut per_page_metadata, branch_markdown_content).unwrap();
+                        per_page_metadata.push_str("\">");
+
+                        const PER_PAGE_METADATA_REPLACEMENT_STRING: &str = "<!-- treehouse-ca37057a-cff5-45b3-8415-3b02dbf6c799-per-branch-metadata -->";
+                        return Html(content.replacen(
+                            PER_PAGE_METADATA_REPLACEMENT_STRING,
+                            &per_page_metadata,
+                            // Replace one under the assumption that it appears in all pages.
+                            1,
+                        ));
+                    }
+                    Err(e) => {
+                        error!("error while reading file {file_path:?}: {e:?}");
+                    }
+                }
+            }
+        }
+
+        Html(state.system_pages.four_oh_four.clone())
+    } else {
+        Html(state.system_pages.b_docs.clone())
+    }
+}

crates/treehouse/src/html/tree.rs

@@ -61,7 +61,7 @@ pub fn branch_to_html(
             s.push_str("<div>");
         }
 
-        let raw_block_content = &source[branch.content.clone()];
+        let raw_block_content = &source.input()[branch.content.clone()];
         let mut unindented_block_content = String::with_capacity(raw_block_content.len());
         for line in raw_block_content.lines() {
             // Bit of a jank way to remove at most branch.indent_level spaces from the front.
@@ -93,7 +93,11 @@ pub fn branch_to_html(
                             .get(linked)
                             .map(|&branch_id| {
                                 (
-                                    format!("#{}", treehouse.tree.branch(branch_id).html_id).into(),
+                                    format!(
+                                        "/b?{}",
+                                        treehouse.tree.branch(branch_id).attributes.id
+                                    )
+                                    .into(),
                                     "".into(),
                                 )
                             }),
@@ -144,8 +148,8 @@ pub fn branch_to_html(
 
             write!(
                 s,
-                "<a class=\"icon icon-permalink\" href=\"#{}\" title=\"permalink\"></a>",
-                EscapeAttribute(&branch.html_id)
+                "<a class=\"icon icon-permalink\" href=\"/b?{}\" title=\"permalink\"></a>",
+                EscapeAttribute(&branch.attributes.id)
             )
             .unwrap();
         }

crates/treehouse/src/main.rs

@@ -3,10 +3,11 @@ use std::path::Path;
 use clap::Parser;
 use cli::{
     fix::{fix_all_cli, fix_file_cli},
-    generate::{self, regenerate_or_report_error},
+    generate::regenerate_or_report_error,
+    serve::serve,
     Command, Paths, ProgramArgs,
 };
-use log::{error, info};
+use log::{error, info, warn};
 
 mod cli;
 mod config;
@@ -30,14 +31,17 @@ async fn fallible_main() -> anyhow::Result<()> {
     };
 
     match args.command {
-        Command::Generate(regenerate_args) => {
+        Command::Generate(_generate_args) => {
             info!("regenerating using directories: {paths:#?}");
-
-            regenerate_or_report_error(&paths);
-
-            if let Some(port) = regenerate_args.serve {
-                generate::web_server(port).await?;
+            regenerate_or_report_error(&paths)?;
+            warn!("`generate` is for debugging only and the files cannot be fully served using a static file server; use `treehouse serve` if you wish to start a treehouse server");
         }
+        Command::Serve {
+            generate: _,
+            serve: serve_args,
+        } => {
+            let treehouse = regenerate_or_report_error(&paths)?;
+            serve(treehouse, &paths, serve_args.port).await?;
         }
 
         Command::Fix(fix_args) => fix_file_cli(fix_args)?,

crates/treehouse/src/state.rs

@@ -10,7 +10,28 @@ use ulid::Ulid;
 
 use crate::tree::{SemaBranchId, SemaRoots, SemaTree};
 
-pub type Files = SimpleFiles<String, String>;
+#[derive(Debug, Clone)]
+pub enum Source {
+    Tree { input: String, tree_path: String },
+    Other(String),
+}
+
+impl Source {
+    pub fn input(&self) -> &str {
+        match &self {
+            Source::Tree { input, .. } => input,
+            Source::Other(source) => source,
+        }
+    }
+}
+
+impl AsRef<str> for Source {
+    fn as_ref(&self) -> &str {
+        self.input()
+    }
+}
+
+pub type Files = SimpleFiles<String, Source>;
 pub type FileId = <Files as codespan_reporting::files::Files<'static>>::FileId;
 
 /// Treehouse compilation context.
@@ -22,19 +43,9 @@ pub struct Treehouse {
     pub branches_by_named_id: HashMap<String, SemaBranchId>,
     pub roots: HashMap<String, SemaRoots>,
 
-    // Bit of a hack because I don't wanna write my own `Files`.
-    tree_paths: Vec<Option<String>>,
-
     missingno_generator: ulid::Generator,
 }
 
-#[derive(Debug, Clone)]
-pub struct BranchRef {
-    pub html_id: String,
-    pub file_id: FileId,
-    pub kind_span: Range<usize>,
-}
-
 impl Treehouse {
     pub fn new() -> Self {
         Self {
@@ -45,25 +56,16 @@ impl Treehouse {
             branches_by_named_id: HashMap::new(),
             roots: HashMap::new(),
 
-            tree_paths: vec![],
-
             missingno_generator: ulid::Generator::new(),
         }
     }
 
-    pub fn add_file(
-        &mut self,
-        filename: String,
-        tree_path: Option<String>,
-        source: String,
-    ) -> FileId {
-        let id = self.files.add(filename, source);
-        self.tree_paths.push(tree_path);
-        id
+    pub fn add_file(&mut self, filename: String, source: Source) -> FileId {
+        self.files.add(filename, source)
     }
 
     /// Get the source code of a file, assuming it was previously registered.
-    pub fn source(&self, file_id: FileId) -> &str {
+    pub fn source(&self, file_id: FileId) -> &Source {
         self.files
             .get(file_id)
             .expect("file should have been registered previously")
@@ -79,7 +81,10 @@ impl Treehouse {
     }
 
     pub fn tree_path(&self, file_id: FileId) -> Option<&str> {
-        self.tree_paths[file_id].as_deref()
+        match self.source(file_id) {
+            Source::Tree { tree_path, .. } => Some(tree_path),
+            Source::Other(_) => None,
+        }
     }
 
     pub fn report_diagnostics(&self) -> anyhow::Result<()> {
@@ -98,6 +103,12 @@ impl Treehouse {
             .generate()
             .expect("just how much disk space do you have?")
     }
+
+    pub fn has_errors(&self) -> bool {
+        self.diagnostics
+            .iter()
+            .any(|diagnostic| diagnostic.severity == Severity::Error)
+    }
 }
 
 pub struct TomlError {

crates/treehouse/src/tree/attributes.rs

@@ -1,5 +1,15 @@
 use serde::Deserialize;
 
+/// Top-level `%%` root attributes.
+#[derive(Debug, Default, Clone, PartialEq, Eq, Deserialize)]
+pub struct RootAttributes {
+    /// Title of the generated .html page.
+    ///
+    /// The page's tree path is used if empty.
+    #[serde(default)]
+    pub title: String,
+}
+
 /// Branch attributes.
 #[derive(Debug, Default, Clone, PartialEq, Eq, Deserialize)]
 pub struct Attributes {

crates/treehouse/src/tree/mod.rs

@@ -9,10 +9,12 @@ use treehouse_format::{
 };
 
 use crate::{
-    state::{toml_error_to_diagnostic, FileId, TomlError, Treehouse},
+    state::{toml_error_to_diagnostic, FileId, Source, TomlError, Treehouse},
     tree::attributes::{Attributes, Content},
 };
 
+use self::attributes::RootAttributes;
+
 #[derive(Debug, Default, Clone)]
 pub struct SemaTree {
     branches: Vec<SemaBranch>,
@@ -35,12 +37,14 @@ impl SemaTree {
 
 #[derive(Debug, Clone)]
 pub struct SemaRoots {
+    pub attributes: RootAttributes,
     pub branches: Vec<SemaBranchId>,
 }
 
 impl SemaRoots {
     pub fn from_roots(treehouse: &mut Treehouse, file_id: FileId, roots: Roots) -> Self {
         Self {
+            attributes: Self::parse_attributes(treehouse, file_id, &roots),
             branches: roots
                 .branches
                 .into_iter()
@@ -48,6 +52,44 @@ impl SemaRoots {
                 .collect(),
         }
     }
+
+    fn parse_attributes(
+        treehouse: &mut Treehouse,
+        file_id: FileId,
+        roots: &Roots,
+    ) -> RootAttributes {
+        let source = treehouse.source(file_id);
+
+        let mut successfully_parsed = true;
+        let mut attributes = if let Some(attributes) = &roots.attributes {
+            toml_edit::de::from_str(&source.input()[attributes.data.clone()]).unwrap_or_else(
+                |error| {
+                    treehouse
+                        .diagnostics
+                        .push(toml_error_to_diagnostic(TomlError {
+                            message: error.message().to_owned(),
+                            span: error.span(),
+                            file_id,
+                            input_range: attributes.data.clone(),
+                        }));
+                    successfully_parsed = false;
+                    RootAttributes::default()
+                },
+            )
+        } else {
+            RootAttributes::default()
+        };
+        let successfully_parsed = successfully_parsed;
+
+        if successfully_parsed && attributes.title.is_empty() {
+            attributes.title = match treehouse.source(file_id) {
+                Source::Tree { tree_path, .. } => tree_path.clone(),
+                _ => panic!("parse_attributes called for a non-.tree file"),
+            }
+        }
+
+        attributes
+    }
 }
 
 /// Analyzed branch.
@@ -132,7 +174,8 @@ impl SemaBranch {
 
         let mut successfully_parsed = true;
         let mut attributes = if let Some(attributes) = &branch.attributes {
-            toml_edit::de::from_str(&source[attributes.data.clone()]).unwrap_or_else(|error| {
+            toml_edit::de::from_str(&source.input()[attributes.data.clone()]).unwrap_or_else(
+                |error| {
                     treehouse
                         .diagnostics
                         .push(toml_error_to_diagnostic(TomlError {
@@ -143,7 +186,8 @@ impl SemaBranch {
                         }));
                     successfully_parsed = false;
                     Attributes::default()
-            })
+                },
+            )
         } else {
             Attributes::default()
         };

static/css/tree.css

@@ -1,3 +1,27 @@
+/*** Icons ***/
+
+:root {
+    --icon-breadcrumb: url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjE2IiB3aWR0aD0iMTYiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggZD0ibTYgMTIgNC00LTQtNCIgZmlsbD0ibm9uZSIgc3Ryb2tlPSIjNTU0MjNlIiBzdHJva2Utd2lkdGg9IjIiLz48L3N2Zz4=');
+    --icon-expand: url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjEyIiB3aWR0aD0iMTIiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggY2xpcC1ydWxlPSJldmVub2RkIiBkPSJtNyA1di0zaC0ydjNoLTN2MmgzdjNoMnYtM2gzdi0yeiIgZmlsbD0iIzU1NDIzZSIgZmlsbC1vcGFjaXR5PSIuNSIgZmlsbC1ydWxlPSJldmVub2RkIi8+PC9zdmc+');
+    --icon-leaf: url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjEyIiB3aWR0aD0iMTIiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PGNpcmNsZSBjeD0iNiIgY3k9IjYiIGZpbGw9IiM1NTQyM2UiIGZpbGwtb3BhY2l0eT0iLjUiIHI9IjIiLz48L3N2Zz4=');
+    --icon-collapse: url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjEyIiB3aWR0aD0iMTIiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggZD0ibTMgNmg2IiBzdHJva2U9IiM1NTQyM2UiIHN0cm9rZS1vcGFjaXR5PSIuNSIgc3Ryb2tlLXdpZHRoPSIyIi8+PC9zdmc+');
+    --icon-more: url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjE2IiB3aWR0aD0iMTYiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggZD0ibTQgNiA0IDQgNC00IiBmaWxsPSJub25lIiBzdHJva2U9IiM1NTQyM2UiIHN0cm9rZS1vcGFjaXR5PSIuNSIgc3Ryb2tlLXdpZHRoPSIyIi8+PC9zdmc+');
+    --icon-permalink: url("data:image/svg+xml;base64,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");
+    --icon-go: url("data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjE2IiB3aWR0aD0iMTYiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggZD0ibTEwLjU4NTggNy0yLjI5Mjg5LTIuMjkyODkgMS40MTQyMS0xLjQxNDIyIDQuNzA3MDggNC43MDcxMS00LjcwNzA4IDQuNzA3MS0xLjQxNDIxLTEuNDE0MiAyLjI5Mjg5LTIuMjkyOWgtNy41ODU4di0yeiIgZmlsbD0iIzU1NDIzZSIvPjwvc3ZnPg==");
+}
+
+@media (prefers-color-scheme: dark) {
+    :root {
+        --icon-breadcrumb: url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjE2IiB3aWR0aD0iMTYiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggZD0ibTYgMTIgNC00LTQtNCIgZmlsbD0ibm9uZSIgc3Ryb2tlPSIjZDdjZGJmIiBzdHJva2Utd2lkdGg9IjIiLz48L3N2Zz4=');
+        --icon-expand: url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjEyIiB3aWR0aD0iMTIiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggY2xpcC1ydWxlPSJldmVub2RkIiBkPSJtNyA1di0zaC0ydjNoLTN2MmgzdjNoMnYtM2gzdi0yeiIgZmlsbD0iI2Q3Y2RiZiIgZmlsbC1vcGFjaXR5PSIuNSIgZmlsbC1ydWxlPSJldmVub2RkIi8+PC9zdmc+');
+        --icon-leaf: url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjEyIiB3aWR0aD0iMTIiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PGNpcmNsZSBjeD0iNiIgY3k9IjYiIGZpbGw9IiNkN2NkYmYiIGZpbGwtb3BhY2l0eT0iLjUiIHI9IjIiLz48L3N2Zz4=');
+        --icon-collapse: url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjEyIiB3aWR0aD0iMTIiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggZD0ibTMgNmg2IiBzdHJva2U9IiNkN2NkYmYiIHN0cm9rZS1vcGFjaXR5PSIuNSIgc3Ryb2tlLXdpZHRoPSIyIi8+PC9zdmc+');
+        --icon-permalink: url("data:image/svg+xml;base64,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");
+        --icon-go: url("data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjE2IiB3aWR0aD0iMTYiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggZD0ibTEwLjU4NTggNy0yLjI5Mjg5LTIuMjkyODkgMS40MTQyMS0xLjQxNDIyIDQuNzA3MDggNC43MDcxMS00LjcwNzA4IDQuNzA3MS0xLjQxNDIxLTEuNDE0MiAyLjI5Mjg5LTIuMjkyOWgtNy41ODU4di0yeiIgZmlsbD0iI2Q3Y2RiZiIvPjwvc3ZnPg==");
+        --icon-more: url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjE2IiB3aWR0aD0iMTYiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggZD0ibTQgNiA0IDQgNC00IiBmaWxsPSJub25lIiBzdHJva2U9IiNkN2NkYmYiIHN0cm9rZS1vcGFjaXR5PSIuNSIgc3Ryb2tlLXdpZHRoPSIyIi8+PC9zdmc+');
+    }
+}
+
 /*** Breadcrumbs ***/
 
 .breadcrumbs {
@@ -22,7 +46,7 @@
 
     background-image:
         /* breadcrumb */
-        url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjE2IiB3aWR0aD0iMTYiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggZD0ibTYgMTIgNC00LTQtNCIgZmlsbD0ibm9uZSIgc3Ryb2tlPSIjNTU0MjNlIiBzdHJva2Utd2lkdGg9IjIiLz48L3N2Zz4=');
+        var(--icon-breadcrumb);
     background-repeat: no-repeat;
     background-position: 50% 50%;
     opacity: 70%;
@@ -107,9 +131,7 @@
 }
 
 .tree details>summary {
-    background-image:
-        /* expand */
-        url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjEyIiB3aWR0aD0iMTIiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggY2xpcC1ydWxlPSJldmVub2RkIiBkPSJtNyA1di0zaC0ydjNoLTN2MmgzdjNoMnYtM2gzdi0yeiIgZmlsbD0iIzU1NDIzZSIgZmlsbC1vcGFjaXR5PSIuNSIgZmlsbC1ydWxlPSJldmVub2RkIi8+PC9zdmc+');
+    background-image: var(--icon-expand);
     background-repeat: no-repeat;
     background-position: var(--tree-icon-position);
     padding-left: var(--tree-icon-space);
@@ -127,9 +149,7 @@
 }
 
 .tree li>div {
-    background-image:
-        /* leaf */
-        url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjEyIiB3aWR0aD0iMTIiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PGNpcmNsZSBjeD0iNiIgY3k9IjYiIGZpbGw9IiM1NTQyM2UiIGZpbGwtb3BhY2l0eT0iLjUiIHI9IjIiLz48L3N2Zz4=');
+    background-image: var(--icon-leaf);
     background-repeat: no-repeat;
     background-position: var(--tree-icon-position);
     padding-left: var(--tree-icon-space);
@@ -139,18 +159,14 @@
 }
 
 .tree details[open]>summary {
-    background-image:
-        /* collapse */
-        url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjEyIiB3aWR0aD0iMTIiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggZD0ibTMgNmg2IiBzdHJva2U9IiM1NTQyM2UiIHN0cm9rZS1vcGFjaXR5PSIuNSIgc3Ryb2tlLXdpZHRoPSIyIi8+PC9zdmc+');
+    background-image: var(--icon-collapse);
 }
 
 .tree details:not([open])>summary>.branch-summary>:last-child::after {
     content: '\00A0';
     display: inline-block;
 
-    background-image:
-        /* more */
-        url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjE2IiB3aWR0aD0iMTYiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggZD0ibTQgNiA0IDQgNC00IiBmaWxsPSJub25lIiBzdHJva2U9IiM1NTQyM2UiIHN0cm9rZS1vcGFjaXR5PSIuNSIgc3Ryb2tlLXdpZHRoPSIyIi8+PC9zdmc+');
+    background-image: var(--icon-more);
     background-repeat: no-repeat;
     background-position: 50% 50%;
 
@@ -217,15 +233,11 @@
 
 
 .tree .icon-permalink {
-    background-image:
-        /* permalink */
-        url("data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjE2IiB3aWR0aD0iMTYiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggZD0ibTcuNjU2ODYgMiAxLjQxNDIxIDEuNDE0MjJjLjY4MDUxLjY4MDUxIDEuMDY0NTMgMS41NDUyMSAxLjE1MjEzIDIuNDMzNjIuODg4NC4wODc2IDEuNzUzMS40NzE2NSAyLjQzMzcgMS4xNTIxNmwxLjQxNDIgMS40MTQyMmMxLjU2MjEgMS41NjIwOSAxLjU2MjEgNC4wOTQ3OCAwIDUuNjU2ODhzLTQuMDk0NzkgMS41NjIxLTUuNjU2ODggMGwtMS40MTQyMi0xLjQxNDJjLS42ODA1MS0uNjgwNi0xLjA2NDU2LTEuNTQ1My0xLjE1MjE2LTIuNDMzNy0uODg4NDEtLjA4NzYtMS43NTMxMS0uNDcxNjItMi40MzM2Mi0xLjE1MjEzbC0xLjQxNDIyLTEuNDE0MjFjLTEuNTYyMDk0LTEuNTYyMS0xLjU2MjA5NC00LjA5NDc2IDAtNS42NTY4NiAxLjU2MjEtMS41NjIwOTQgNC4wOTQ3Ni0xLjU2MjA5NCA1LjY1Njg2IDB6bS42MTggNy42ODkwN2MtLjE0NDMuMDg1MjItLjI5MjgxLjE2MDYxLS40NDQ1NS4yMjYxNi4wMjA4My40ODI1Ny4yMTU0Ni45NTg5Ny41ODM5MSAxLjMyNzM3bDEuNDE0MjEgMS40MTQzYy43ODEwNy43ODEgMi4wNDczNy43ODEgMi44Mjg0NyAwIC43ODEtLjc4MTEuNzgxLTIuMDQ3NCAwLTIuODI4NDdsLTEuNDE0My0xLjQxNDIxYy0uMzY4NC0uMzY4NDUtLjg0NDgtLjU2MzA4LTEuMzI3MzctLjU4MzkxLS4wNjU1NS4xNTE3My0uMTQwOTMuMzAwMjQtLjIyNjE2LjQ0NDU0bDEuODQ2NDMgMS44NDY0NS0xLjQxNDIgMS40MTQyem0tLjYxOC00Ljg2MDY0Yy4zNjg0NC4zNjg0NS41NjMwOC44NDQ4OC41ODM5MSAxLjMyNzQyLS4xNTE3NC4wNjU1NC0uMzAwMjQuMTQwOTMtLjQ0NDU0LjIyNjE1bC0xLjkxNzU0LTEuOTE3NTMtMS40MTQyMSAxLjQxNDIxIDEuOTE3NTMgMS45MTc1M2MtLjA4NTIzLjE0NDMxLS4xNjA2MS4yOTI4Mi0uMjI2MTYuNDQ0NTYtLjQ4MjU0LS4wMjA4My0uOTU4OTctLjIxNTQ3LTEuMzI3NDItLjU4MzkxbC0xLjQxNDIxLTEuNDE0MjJjLS43ODEwNS0uNzgxMDUtLjc4MTA1LTIuMDQ3MzcgMC0yLjgyODQyczIuMDQ3MzctLjc4MTA1IDIuODI4NDIgMHoiIGZpbGw9IiM1NTQyM2UiIGZpbGwtcnVsZT0iZXZlbm9kZCIvPjwvc3ZnPg==");
+    background-image: var(--icon-permalink);
 }
 
 .tree .icon-go {
-    background-image:
-        /* go */
-        url("data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjE2IiB3aWR0aD0iMTYiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggZD0ibTEwLjU4NTggNy0yLjI5Mjg5LTIuMjkyODkgMS40MTQyMS0xLjQxNDIyIDQuNzA3MDggNC43MDcxMS00LjcwNzA4IDQuNzA3MS0xLjQxNDIxLTEuNDE0MiAyLjI5Mjg5LTIuMjkyOWgtNy41ODU4di0yeiIgZmlsbD0iIzU1NDIzZSIvPjwvc3ZnPg==");
+    background-image: var(--icon-go);
 }
 
 .tree a.navigate {
@@ -241,54 +253,14 @@
     opacity: 50%;
 }
 
-.tree :target>details>summary,
-.tree :target>div {
+.tree :target,
+.tree .target {
+
+    &>details>summary,
+    &>div {
         border-bottom: 1px dashed var(--border-2);
         margin-bottom: -1px;
         border-bottom-left-radius: 0;
         border-bottom-right-radius: 0;
     }
-
-@media (prefers-color-scheme: dark) {
-    .breadcrumb::before {
-        background-image:
-            /* breadcrumb */
-            url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjE2IiB3aWR0aD0iMTYiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggZD0ibTYgMTIgNC00LTQtNCIgZmlsbD0ibm9uZSIgc3Ryb2tlPSIjZDdjZGJmIiBzdHJva2Utd2lkdGg9IjIiLz48L3N2Zz4=')
-    }
-
-    .tree details>summary {
-        background-image:
-            /* expand */
-            url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjEyIiB3aWR0aD0iMTIiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggY2xpcC1ydWxlPSJldmVub2RkIiBkPSJtNyA1di0zaC0ydjNoLTN2MmgzdjNoMnYtM2gzdi0yeiIgZmlsbD0iI2Q3Y2RiZiIgZmlsbC1vcGFjaXR5PSIuNSIgZmlsbC1ydWxlPSJldmVub2RkIi8+PC9zdmc+');
-    }
-
-    .tree li>div {
-        background-image:
-            /* leaf */
-            url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjEyIiB3aWR0aD0iMTIiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PGNpcmNsZSBjeD0iNiIgY3k9IjYiIGZpbGw9IiNkN2NkYmYiIGZpbGwtb3BhY2l0eT0iLjUiIHI9IjIiLz48L3N2Zz4=');
-    }
-
-    .tree details[open]>summary {
-        background-image:
-            /* collapse */
-            url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjEyIiB3aWR0aD0iMTIiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggZD0ibTMgNmg2IiBzdHJva2U9IiNkN2NkYmYiIHN0cm9rZS1vcGFjaXR5PSIuNSIgc3Ryb2tlLXdpZHRoPSIyIi8+PC9zdmc+');
-    }
-
-    .tree .icon-permalink {
-        background-image:
-            /* permalink */
-            url("data:image/svg+xml;base64,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");
-    }
-
-    .tree .icon-go {
-        background-image:
-            /* go */
-            url("data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjE2IiB3aWR0aD0iMTYiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggZD0ibTEwLjU4NTggNy0yLjI5Mjg5LTIuMjkyODkgMS40MTQyMS0xLjQxNDIyIDQuNzA3MDggNC43MDcxMS00LjcwNzA4IDQuNzA3MS0xLjQxNDIxLTEuNDE0MiAyLjI5Mjg5LTIuMjkyOWgtNy41ODU4di0yeiIgZmlsbD0iI2Q3Y2RiZiIvPjwvc3ZnPg==");
-    }
-
-    .tree details:not([open])>summary>.branch-summary>:last-child::after {
-        background-image:
-            /* more */
-            url('data:image/svg+xml;base64,PHN2ZyBoZWlnaHQ9IjE2IiB3aWR0aD0iMTYiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHBhdGggZD0ibTQgNiA0IDQgNC00IiBmaWxsPSJub25lIiBzdHJva2U9IiNkN2NkYmYiIHN0cm9rZS1vcGFjaXR5PSIuNSIgc3Ryb2tlLXdpZHRoPSIyIi8+PC9zdmc+');
-    }
 }

static/js/tree.js

@@ -17,6 +17,8 @@ function branchIsOpen(branchID) {
 }
 
 class Branch extends HTMLLIElement {
+    static branchesByNamedID = new Map();
+
     constructor() {
         super();
 
@@ -31,6 +33,9 @@ class Branch extends HTMLLIElement {
         this.details.addEventListener("toggle", _ => {
             saveBranchIsOpen(this.id, this.details.open);
         });
+
+        Branch.branchesByNamedID.set(this.id.split(':')[1], this);
+        console.log(Branch.branchesByNamedID)
     }
 }
 
@@ -47,8 +52,6 @@ class LinkedBranch extends Branch {
         this.linkedTree = this.getAttribute("data-th-link");
         LinkedBranch.byLink.set(this.linkedTree, this);
 
-        this.loadingState = "notloaded";
-
         this.loadingText = document.createElement("p");
         {
             this.loadingText.className = "link-loading";
@@ -109,8 +112,10 @@ function rehash() { // https://www.youtube.com/watch?v=Tv1SYqLllKI
     if (!rehashing) {
         rehashing = true;
         let hash = window.location.hash;
+        if (hash.length > 0) {
             window.location.hash = "";
             window.location.hash = hash;
+        }
         rehashing = false;
     }
 }
@@ -183,9 +188,17 @@ async function navigateToBranch(fragment) {
     }
 }
 
+function getCurrentlyHighlightedBranch() {
+    if (window.location.pathname == "/b" && window.location.search.length > 0) {
+        let shortID = window.location.search.substring(1);
+        return Branch.branchesByNamedID.get(shortID).id;
+    } else {
+        return window.location.hash.substring(1);
+    }
+}
+
 async function navigateToCurrentBranch() {
-    let location = window.location.hash.substring(1);
-    await navigateToBranch(location);
+    await navigateToBranch(getCurrentlyHighlightedBranch());
 }
 
 // When you click on a link, and the destination is within a <details> that is not expanded,
@@ -196,9 +209,9 @@ addEventListener("DOMContentLoaded", navigateToCurrentBranch);
 // When you enter the website through a link someone sent you, it would be nice if the linked branch
 // got expanded by default.
 async function expandLinkedBranch() {
-    let hash = window.location.hash;
-    if (hash.length > 0) {
-        let linkedBranch = document.getElementById(hash.substring(1));
+    let currentlyHighlightedBranch = getCurrentlyHighlightedBranch();
+    if (currentlyHighlightedBranch.length > 0) {
+        let linkedBranch = document.getElementById(currentlyHighlightedBranch);
         if (linkedBranch.children.length > 0 && linkedBranch.children[0].tagName == "DETAILS") {
             expandDetailsRecursively(linkedBranch.children[0]);
         }
@@ -206,3 +219,12 @@ async function expandLinkedBranch() {
 }
 
 addEventListener("DOMContentLoaded", expandLinkedBranch);
+
+async function highlightCurrentBranch() {
+    let branch = document.getElementById(getCurrentlyHighlightedBranch());
+    if (branch != null) {
+        branch.classList.add("target");
+    }
+}
+
+addEventListener("DOMContentLoaded", highlightCurrentBranch);

template/tree.hbs

@@ -5,13 +5,19 @@
 <head>
     <meta charset="UTF-8">
 
-    <title>{{ config.user.title }}</title>
+    <title>{{#if (ne page.title config.user.title)}}{{ page.title }} · {{/if}}{{ config.user.title }}</title>
 
     <meta name="viewport" content="width=device-width, initial-scale=1">
 
-    <meta property="og:title" content="{{ config.user.title }}">
     <meta property="og:site_name" content="{{ config.user.title }}">
-    <meta property="og:description" content="{{ config.user.description }}">
+    <meta property="og:title" content="{{ page.title }}">
+    {{!--
+    This is a bit of a hack to quickly insert metadata into generated pages without going through Handlebars, which
+    would involve registering, parsing, and generating a page from a template.
+    Yes it would be more flexible that way, but it doesn't need to be.
+    It just needs to be a string replacement.
+    --}}
+    <!-- treehouse-ca37057a-cff5-45b3-8415-3b02dbf6c799-per-branch-metadata -->
 
     <link rel="stylesheet" href="{{ config.site }}/static/css/main.css">
     <link rel="stylesheet" href="{{ config.site }}/static/css/tree.css">
@@ -34,9 +40,9 @@
             </svg>
         </a>
 
-        {{#if breadcrumbs}}
+        {{#if page.breadcrumbs}}
         <ol class="breadcrumbs">
-            {{{ breadcrumbs }}}
+            {{{ page.breadcrumbs }}}
         </ol>
         {{/if}}
     </nav>
@@ -57,7 +63,8 @@
                 if you don't believe me, you're free to inspect the source yourself! all the scripts are written
                 lovingly in vanilla JS (not minified!) by yours truly ❤️</p>
             <small>and if this box is annoying, feel free to block it with uBlock Origin or something. I have no
-                way of remembering you closed it, and don't wanna host this site on a dynamic server.</small>
+                way of remembering you closed it, and don't wanna add a database to this website. simplicity
+                rules!</small>
         </div>
     </noscript>
 
@@ -70,7 +77,7 @@
     </div>
 
     <main class="tree">
-        {{{ tree }}}
+        {{{ page.tree }}}
     </main>
 </body>