add _xesite_frontmatter extension

Signed-off-by: Xe Iaso <me@christine.website>

10 files changed, 179 insertions, 95 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 591696a..b86dbe7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3205,6 +3205,7 @@ dependencies = [
  "serde",
  "serde_derive",
  "serde_json",
+ "xesite_types",
 ]
 
 [[package]]
@@ -3260,10 +3261,19 @@ dependencies = [
  "url",
  "uuid 0.8.2",
  "xe_jsonfeed",
+ "xesite_types",
  "xml-rs",
 ]
 
 [[package]]
+name = "xesite_types"
+version = "0.1.0"
+dependencies = [
+ "chrono",
+ "serde",
+]
+
+[[package]]
 name = "xml-rs"
 version = "0.8.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/Cargo.toml b/Cargo.toml
index 62f4a5a..319a27f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -48,6 +48,8 @@ xml-rs = "0.8"
 url = "2"
 uuid = { version = "0.8", features = ["serde", "v4"] }
 
+xesite_types = { path = "./lib/xesite_types" }
+
 # workspace dependencies
 cfcache = { path = "./lib/cfcache" }
 xe_jsonfeed = { path = "./lib/jsonfeed" }
diff --git a/docs/jsonfeed_extensions.markdown b/docs/jsonfeed_extensions.markdown
new file mode 100644
index 0000000..63a8aa2
--- /dev/null
+++ b/docs/jsonfeed_extensions.markdown
@@ -0,0 +1,27 @@
+# JSON Feed Extensions
+
+Here is the documentation of all of my JSON Feed extensions. I have created
+these JSON Feed extensions in order to give users more metadata about my
+articles and talks.
+
+## `_xesite_frontmatter`
+
+This extension is added to [JSON Feed
+Items](https://www.jsonfeed.org/version/1.1/#items-a-name-items-a) and gives
+readers a copy of the frontmatter data that I annotate my posts with. The
+contents of this will vary by post, but will have any of the following fields:
+
+* `about` (required, string) is a link to this documentation. It gives readers
+  of the JSON Feed information about what this extension does. This is for
+  informational purposes only and can safely be ignored by programs.
+* `series` (optional, string) is the optional blogpost series name that this
+  item belongs to. When I post multiple posts about the same topic, I will
+  usually set the `series` to the same value so that it is more discoverable [on
+  my series index page](https://xeiaso.net/blog/series).
+* `slides_link` (optional, string) is a link to the PDF containing the slides
+  for a given talk. This is always set on talks, but is technically optional
+  because not everything I do is a talk.
+* `vod` (optional, string) is an object that describes where you can watch the
+  Video On Demand (vod) for the writing process of a post. This is an object
+  that always contains the fields `twitch` and `youtube`. These will be URLs to
+  the videos so that you can watch them on demand.
diff --git a/lib/jsonfeed/Cargo.toml b/lib/jsonfeed/Cargo.toml
index 99172fd..ad17ccd 100644
--- a/lib/jsonfeed/Cargo.toml
+++ b/lib/jsonfeed/Cargo.toml
@@ -13,3 +13,5 @@ error-chain = "0.12"
 serde = "1"
 serde_derive = "1"
 serde_json = "1"
+
+xesite_types = { path = "../xesite_types" }
diff --git a/lib/jsonfeed/src/builder.rs b/lib/jsonfeed/src/builder.rs
index 640a280..4ce47a4 100644
--- a/lib/jsonfeed/src/builder.rs
+++ b/lib/jsonfeed/src/builder.rs
@@ -90,6 +90,7 @@ pub struct ItemBuilder {
     pub author: Option<Author>,
     pub tags: Option<Vec<String>>,
     pub attachments: Option<Vec<Attachment>>,
+    pub xesite_frontmater: Option<xesite_types::Frontmatter>,
 }
 
 impl ItemBuilder {
@@ -108,6 +109,7 @@ impl ItemBuilder {
             author: None,
             tags: None,
             attachments: None,
+            xesite_frontmater: None,
         }
     }
 
@@ -180,6 +182,11 @@ impl ItemBuilder {
         self
     }
 
+    pub fn xesite_frontmatter(mut self, fm: xesite_types::Frontmatter) -> ItemBuilder {
+        self.xesite_frontmater = Some(fm);
+        self
+    }
+
     pub fn build(self) -> Result<Item> {
         if self.id.is_none() || self.content.is_none() {
             return Err("missing field 'id' or 'content_*'".into());
@@ -198,6 +205,7 @@ impl ItemBuilder {
             author: self.author,
             tags: self.tags,
             attachments: self.attachments,
+            xesite_frontmatter: self.xesite_frontmater,
         })
     }
 }
diff --git a/lib/jsonfeed/src/item.rs b/lib/jsonfeed/src/item.rs
index 0f7d6ab..7b5d734 100644
--- a/lib/jsonfeed/src/item.rs
+++ b/lib/jsonfeed/src/item.rs
@@ -1,3 +1,4 @@
+use std::collections::HashMap;
 use std::default::Default;
 use std::fmt;
 
@@ -31,6 +32,9 @@ pub struct Item {
     pub author: Option<Author>,
     pub tags: Option<Vec<String>>,
     pub attachments: Option<Vec<Attachment>>,
+
+    // xesite extensions
+    pub xesite_frontmatter: Option<xesite_types::Frontmatter>,
 }
 
 impl Item {
@@ -55,6 +59,7 @@ impl Default for Item {
             author: None,
             tags: None,
             attachments: None,
+            xesite_frontmatter: None,
         }
     }
 }
@@ -113,6 +118,9 @@ impl Serialize for Item {
         if self.attachments.is_some() {
             state.serialize_field("attachments", &self.attachments)?;
         }
+        if self.xesite_frontmatter.is_some() {
+            state.serialize_field("_xesite_frontmatter", &self.xesite_frontmatter)?;
+        }
         state.end()
     }
 }
@@ -319,6 +327,7 @@ impl<'de> Deserialize<'de> for Item {
                     author,
                     tags,
                     attachments,
+                    xesite_frontmatter: None,
                 })
             }
         }
diff --git a/lib/xesite_types/Cargo.toml b/lib/xesite_types/Cargo.toml
new file mode 100644
index 0000000..5aec478
--- /dev/null
+++ b/lib/xesite_types/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "xesite_types"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+chrono = { version = "0.4", features = [ "serde" ] }
+serde = { version = "1.0", features = [ "derive" ] }
diff --git a/lib/xesite_types/src/lib.rs b/lib/xesite_types/src/lib.rs
new file mode 100644
index 0000000..68ae4c4
--- /dev/null
+++ b/lib/xesite_types/src/lib.rs
@@ -0,0 +1,37 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Eq, PartialEq, Deserialize, Default, Debug, Serialize, Clone)]
+pub struct Frontmatter {
+    #[serde(default = "frontmatter_about")]
+    pub about: String,
+    #[serde(skip_serializing)]
+    pub title: String,
+    #[serde(skip_serializing)]
+    pub date: String,
+    #[serde(skip_serializing)]
+    pub author: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub series: Option<String>,
+    #[serde(skip_serializing)]
+    pub tags: Option<Vec<String>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub slides_link: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub image: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub thumb: Option<String>,
+    #[serde(skip_serializing)]
+    pub redirect_to: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub vod: Option<Vod>,
+}
+
+fn frontmatter_about() -> String {
+    "https://xeiaso.net/blog/api-jsonfeed-extensions#_xesite_frontmatter".to_string()
+}
+
+#[derive(Eq, PartialEq, Deserialize, Default, Debug, Serialize, Clone)]
+pub struct Vod {
+    pub twitch: String,
+    pub youtube: String,
+}
diff --git a/src/post/frontmatter.rs b/src/post/frontmatter.rs
index fa4c65c..67b96ab 100644
--- a/src/post/frontmatter.rs
+++ b/src/post/frontmatter.rs
@@ -1,26 +1,6 @@
 /// This code was borrowed from @fasterthanlime.
 use color_eyre::eyre::Result;
-use serde::{Deserialize, Serialize};
-
-#[derive(Eq, PartialEq, Deserialize, Default, Debug, Serialize, Clone)]
-pub struct Data {
-    pub title: String,
-    pub date: String,
-    pub series: Option<String>,
-    pub tags: Option<Vec<String>>,
-    pub slides_link: Option<String>,
-    pub image: Option<String>,
-    pub thumb: Option<String>,
-    pub show: Option<bool>,
-    pub redirect_to: Option<String>,
-    pub vod: Option<Vod>,
-}
-
-#[derive(Eq, PartialEq, Deserialize, Default, Debug, Serialize, Clone)]
-pub struct Vod {
-    pub twitch: String,
-    pub youtube: String,
-}
+pub use xesite_types::Frontmatter as Data;
 
 enum State {
     SearchForStart,
@@ -37,85 +17,83 @@ enum Error {
     Yaml(#[from] serde_yaml::Error),
 }
 
-impl Data {
-    pub fn parse(input: &str) -> Result<(Data, usize)> {
-        let mut state = State::SearchForStart;
+pub fn parse(input: &str) -> Result<(Data, usize)> {
+    let mut state = State::SearchForStart;
 
-        let mut payload = None;
-        let offset;
+    let mut payload = None;
+    let offset;
 
-        let mut chars = input.char_indices();
-        'parse: loop {
-            let (idx, ch) = match chars.next() {
-                Some(x) => x,
-                None => return Err(Error::EOF)?,
-            };
-            match &mut state {
-                State::SearchForStart => match ch {
-                    '-' => {
-                        state = State::ReadingMarker {
-                            count: 1,
-                            end: false,
-                        };
-                    }
-                    '\n' | '\t' | ' ' => {
-                        // ignore whitespace
+    let mut chars = input.char_indices();
+    'parse: loop {
+        let (idx, ch) = match chars.next() {
+            Some(x) => x,
+            None => return Err(Error::EOF)?,
+        };
+        match &mut state {
+            State::SearchForStart => match ch {
+                '-' => {
+                    state = State::ReadingMarker {
+                        count: 1,
+                        end: false,
+                    };
+                }
+                '\n' | '\t' | ' ' => {
+                    // ignore whitespace
+                }
+                _ => {
+                    panic!("Start of frontmatter not found");
+                }
+            },
+            State::ReadingMarker { count, end } => match ch {
+                '-' => {
+                    *count += 1;
+                    if *count == 3 {
+                        state = State::SkipNewline { end: *end };
                     }
-                    _ => {
-                        panic!("Start of frontmatter not found");
-                    }
-                },
-                State::ReadingMarker { count, end } => match ch {
-                    '-' => {
-                        *count += 1;
-                        if *count == 3 {
-                            state = State::SkipNewline { end: *end };
-                        }
-                    }
-                    _ => {
-                        panic!("Malformed frontmatter marker");
-                    }
-                },
-                State::SkipNewline { end } => match ch {
-                    '\n' => {
-                        if *end {
-                            offset = idx + 1;
-                            break 'parse;
-                        } else {
-                            state = State::ReadingFrontMatter {
-                                buf: String::new(),
-                                line_start: true,
-                            };
-                        }
-                    }
-                    _ => panic!("Expected newline, got {:?}", ch),
-                },
-                State::ReadingFrontMatter { buf, line_start } => match ch {
-                    '-' if *line_start => {
-                        let mut state_temp = State::ReadingMarker {
-                            count: 1,
-                            end: true,
+                }
+                _ => {
+                    panic!("Malformed frontmatter marker");
+                }
+            },
+            State::SkipNewline { end } => match ch {
+                '\n' => {
+                    if *end {
+                        offset = idx + 1;
+                        break 'parse;
+                    } else {
+                        state = State::ReadingFrontMatter {
+                            buf: String::new(),
+                            line_start: true,
                         };
-                        std::mem::swap(&mut state, &mut state_temp);
-                        if let State::ReadingFrontMatter { buf, .. } = state_temp {
-                            payload = Some(buf);
-                        } else {
-                            unreachable!();
-                        }
                     }
-                    ch => {
-                        buf.push(ch);
-                        *line_start = ch == '\n';
+                }
+                _ => panic!("Expected newline, got {:?}", ch),
+            },
+            State::ReadingFrontMatter { buf, line_start } => match ch {
+                '-' if *line_start => {
+                    let mut state_temp = State::ReadingMarker {
+                        count: 1,
+                        end: true,
+                    };
+                    std::mem::swap(&mut state, &mut state_temp);
+                    if let State::ReadingFrontMatter { buf, .. } = state_temp {
+                        payload = Some(buf);
+                    } else {
+                        unreachable!();
                     }
-                },
-            }
+                }
+                ch => {
+                    buf.push(ch);
+                    *line_start = ch == '\n';
+                }
+            },
         }
+    }
 
-        // unwrap justification: option set in state machine, Rust can't statically analyze it
-        let payload = payload.unwrap();
+    // unwrap justification: option set in state machine, Rust can't statically analyze it
+    let payload = payload.unwrap();
 
-        let fm: Self = serde_yaml::from_str(&payload)?;
+    let fm: Data = serde_yaml::from_str(&payload)?;
 
-        Ok((fm, offset))
-    }
+    Ok((fm, offset))
 }
diff --git a/src/post/mod.rs b/src/post/mod.rs
index f24b29c..5c2ed2d 100644
--- a/src/post/mod.rs
+++ b/src/post/mod.rs
@@ -30,7 +30,7 @@ pub struct NewPost {
 impl Into<xe_jsonfeed::Item> for Post {
     fn into(self) -> xe_jsonfeed::Item {
         let mut result = xe_jsonfeed::Item::builder()
-            .title(self.front_matter.title)
+            .title(self.front_matter.title.clone())
             .content_html(self.body_html)
             .id(format!("https://xeiaso.net/{}", self.link))
             .url(format!("https://xeiaso.net/{}", self.link))
@@ -40,7 +40,8 @@ impl Into<xe_jsonfeed::Item> for Post {
                     .name("Xe Iaso")
                     .url("https://xeiaso.net")
                     .avatar("https://xeiaso.net/static/img/avatar.png"),
-            );
+            )
+            .xesite_frontmatter(self.front_matter.clone());
 
         let mut tags: Vec<String> = vec![];
 
@@ -96,7 +97,7 @@ async fn read_post(
     let body = fs::read_to_string(fname.clone())
         .await
         .wrap_err_with(|| format!("can't read {:?}", fname))?;
-    let (front_matter, content_offset) = frontmatter::Data::parse(body.clone().as_str())
+    let (front_matter, content_offset) = frontmatter::parse(body.clone().as_str())
         .wrap_err_with(|| format!("can't parse frontmatter of {:?}", fname))?;
     let body = &body[content_offset..];
     let date = NaiveDate::parse_from_str(&front_matter.clone().date, "%Y-%m-%d")