add a tagging system to the website

src/doc.rs

@@ -0,0 +1,138 @@
+use chrono::{DateTime, Utc};
+use codespan_reporting::diagnostic::{Diagnostic, Label};
+use serde::Deserialize;
+
+use crate::{
+    state::{FileId, TomlError, Treehouse, toml_error_to_diagnostic},
+    tree::attributes::{Picture, timestamp_from_id},
+};
+
+#[derive(Debug, Clone)]
+pub struct Doc {
+    pub attributes: Attributes,
+    pub text: String,
+}
+
+#[derive(Debug, Clone, Default, Deserialize)]
+pub struct Attributes {
+    /// Template to use for generating the page.
+    /// Defaults to `_tree.hbs`.
+    #[serde(default)]
+    pub template: Option<String>,
+
+    /// The unique ID of the doc.
+    /// Required to appear in feeds.
+    ///
+    /// - New format: `doc?{date}-{name}`, where `{date}` is a `YYYY-MM-DD` date, and `{name}` is
+    ///   the filename of the document (or otherwise a unique name which doesn't conflict with docs
+    ///   made that day.)
+    /// - Old format: `b?{ulid}`, where `{ulid}` is a ULID.
+    ///   This follows the format of branches.
+    #[serde(default)]
+    pub id: String,
+
+    /// Title of the page.
+    /// The only necessary field.
+    /// Unlike tree pages, doc pages always have titles.
+    pub title: String,
+
+    /// Tags assigned to the document.
+    /// Generally, you want to assign public documents to #all for them to show up on the front page.
+    #[serde(default)]
+    pub tags: Vec<String>,
+
+    /// Timestamp when the document was last updated.
+    /// Required for inclusion in feeds.
+    /// For pages with old style IDs, this is inferred from the ID.
+    #[serde(default)]
+    pub updated: Option<DateTime<Utc>>,
+
+    /// ID of picture attached to the page, to be used as a thumbnail.
+    #[serde(default)]
+    pub thumbnail: Option<Picture>,
+
+    /// Additional scripts to load into to the page.
+    /// These are relative to the /static/js directory.
+    #[serde(default)]
+    pub scripts: Vec<String>,
+
+    /// Additional styles to load into to the page.
+    /// These are relative to the /static/css directory.
+    #[serde(default)]
+    pub styles: Vec<String>,
+
+    /// If not `None`, the page will get an additional 'feed' field in template data, containing
+    /// a feed of pages with the specified tag.
+    #[serde(default)]
+    pub include_feed: Option<IncludeFeed>,
+}
+
+#[derive(Debug, Clone, Deserialize)]
+pub struct IncludeFeed {
+    /// The tag to look for.
+    pub tag: String,
+
+    /// The title of the feed shown on the page.
+    pub title: String,
+}
+
+impl Doc {
+    pub fn parse(treehouse: &mut Treehouse, file_id: FileId) -> (Doc, Vec<Diagnostic<FileId>>) {
+        let mut diagnostics = vec![];
+
+        let source = treehouse.source(file_id).input();
+
+        let (front_matter, text) = source.split_once("+++").unwrap_or(("", source));
+        let attributes_span = 0..front_matter.len();
+        let mut attributes: Attributes =
+            toml_edit::de::from_str(front_matter).unwrap_or_else(|error| {
+                diagnostics.push(toml_error_to_diagnostic(TomlError {
+                    message: error.message().to_owned(),
+                    span: error.span(),
+                    file_id,
+                    input_range: attributes_span.clone(),
+                }));
+                Attributes::default()
+            });
+
+        // Infer attributes
+
+        if let Some(branch_id) = attributes.id.strip_prefix("b?")
+            && let Some(timestamp) = timestamp_from_id(branch_id)
+        {
+            attributes.updated = Some(timestamp);
+        }
+
+        // Emit warnings
+
+        if !attributes.tags.is_empty() {
+            if attributes.id.is_empty() {
+                diagnostics.push(
+                    Diagnostic::warning()
+                        .with_code("attr")
+                        .with_message("doc is tagged but missing id attribute")
+                        .with_labels(vec![Label::primary(file_id, attributes_span.clone())])
+                        .with_notes(vec!["id is required for showing up in feeds".into()]),
+                );
+            } else if attributes.updated.is_none() {
+                diagnostics.push(
+                    Diagnostic::warning()
+                        .with_code("attr")
+                        .with_message("doc is tagged but missing updated attribute")
+                        .with_labels(vec![Label::primary(file_id, attributes_span.clone())])
+                        .with_notes(vec![
+                            "updated attribute is required for showing up in feeds".into(),
+                        ]),
+                );
+            }
+        }
+
+        (
+            Doc {
+                attributes,
+                text: text.to_owned(),
+            },
+            diagnostics,
+        )
+    }
+}