feat(liquid): Generalize page.is_post to page.collection

`page.collection` contains the collection slug which is `posts` for,
well, the built-in posts collection.

This is a step towards cobalt-org#323

BREAKING CHANGE: `page.is_post` is replaced by `page.collection`

Generally, it'll look like
`{% if page.is_post %}`
and can be replaced by
`{% if page.collection == "posts" %}`

though `cobalt migrate` should do this for you.

src/bin/cobalt/migrate.rs

@@ -88,7 +88,7 @@ fn migrate_variables(content: String) -> Result<String> {
             (r#"\{\{\s*content\s*}}"#, "{{ page.content }}"),
             (r#"\{\{\s*previous\.(.*?)\s*}}"#, "{{ page.previous.$1 }}"),
             (r#"\{\{\s*next\.(.*?)\s*}}"#, "{{ page.next.$1 }}"),
-            (r#"\{%\s*if\s+is_post\s*%}"#, "{% if page.is_post %}"),
+            (r#"\{%\s*if\s+is_post\s*%}"#, r#"{% if page.collection == "posts" %}"#),
             (r#"\{%\s*if\s+previous\s*%}"#, "{% if page.previous %}"),
             (r#"\{%\s*if\s+next\s*%}"#, "{% if page.next %}"),
             (r#"\{%\s*if\s+draft\s*%}"#, "{% if page.is_draft %}"),

src/cobalt.rs

@@ -100,7 +100,9 @@ pub fn build(config: &Config) -> Result<()> {
     let default_date = cobalt_model::DateTime::default();
 
     let (mut posts, documents): (Vec<Document>, Vec<Document>) =
-        documents.into_iter().partition(|x| x.front.is_post);
+        documents
+            .into_iter()
+            .partition(|x| x.front.collection == "posts");
 
     // sort documents by date, if there's no date (none was provided or it couldn't be read) then
     // fall back to the default date

src/cobalt_model/collection.rs

@@ -85,6 +85,8 @@ impl CollectionBuilder {
             attributes.insert("jsonfeed".to_owned(), liquid::Value::str(jsonfeed));
         }
 
+        let default = default.set_collection(slug.clone());
+
         let new = Collection {
             title,
             slug,

src/cobalt_model/config.rs

@@ -51,7 +51,8 @@ pub struct PageBuilder {
 
 impl From<PageBuilder> for collection::CollectionBuilder {
     fn from(config: PageBuilder) -> Self {
-        let slug = Some("pages".to_owned());
+        // Pages aren't publicly exposed as a collection
+        let slug = Some("".to_owned());
         let dir = Some(".".to_owned());
         let default = config.default.merge_excerpt_separator("".to_owned());
         collection::CollectionBuilder {
@@ -105,10 +106,6 @@ impl From<PostBuilder> for collection::CollectionBuilder {
             default,
         } = config;
 
-        // HACK: We shouldn't allow a user to set this in the first place but too lazy to setup
-        // error reporting in here.
-        let default = default.set_post(true);
-
         let slug = Some("posts".to_owned());
         collection::CollectionBuilder {
             title,

src/cobalt_model/frontmatter.rs

@@ -79,12 +79,12 @@ pub struct FrontmatterBuilder {
     pub layout: Option<String>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub is_draft: Option<bool>,
+    #[serde(skip_serializing_if = "liquid::Object::is_empty")]
+    pub data: liquid::Object,
     // Controlled by where the file is found.  We might allow control over the type at a later
     // point but we need to first define those semantics.
     #[serde(skip)]
-    pub is_post: Option<bool>,
-    #[serde(skip_serializing_if = "liquid::Object::is_empty")]
-    pub data: liquid::Object,
+    pub collection: Option<String>,
 }
 
 impl FrontmatterBuilder {
@@ -172,9 +172,9 @@ impl FrontmatterBuilder {
         }
     }
 
-    pub fn set_post<B: Into<Option<bool>>>(self, is_post: B) -> Self {
+    pub fn set_collection<S: Into<Option<String>>>(self, collection: S) -> Self {
         Self {
-            is_post: is_post.into(),
+            collection: collection.into(),
             ..self
         }
     }
@@ -227,8 +227,8 @@ impl FrontmatterBuilder {
     }
 
     #[cfg(test)]
-    pub fn merge_post<B: Into<Option<bool>>>(self, post: B) -> Self {
-        self.merge(Self::new().set_post(post.into()))
+    pub fn merge_collection<S: Into<Option<String>>>(self, collection: S) -> Self {
+        self.merge(Self::new().set_collection(collection.into()))
     }
 
     pub fn merge_data(self, other_data: liquid::Object) -> Self {
@@ -244,7 +244,7 @@ impl FrontmatterBuilder {
             format,
             layout,
             is_draft,
-            is_post,
+            collection,
             data,
         } = self;
         Self {
@@ -259,7 +259,7 @@ impl FrontmatterBuilder {
             format: format,
             layout: layout,
             is_draft: is_draft,
-            is_post: is_post,
+            collection: collection,
             data: merge_objects(data, other_data),
         }
     }
@@ -277,7 +277,7 @@ impl FrontmatterBuilder {
             format,
             layout,
             is_draft,
-            is_post,
+            collection,
             data,
         } = self;
         let Self {
@@ -292,7 +292,7 @@ impl FrontmatterBuilder {
             format: other_format,
             layout: other_layout,
             is_draft: other_is_draft,
-            is_post: other_is_post,
+            collection: other_collection,
             data: other_data,
         } = other;
         Self {
@@ -307,7 +307,7 @@ impl FrontmatterBuilder {
             format: format.or_else(|| other_format),
             layout: layout.or_else(|| other_layout),
             is_draft: is_draft.or_else(|| other_is_draft),
-            is_post: is_post.or_else(|| other_is_post),
+            collection: collection.or_else(|| other_collection),
             data: merge_objects(data, other_data),
         }
     }
@@ -362,11 +362,11 @@ impl FrontmatterBuilder {
             format,
             layout,
             is_draft,
-            is_post,
+            collection,
             data,
         } = self;
 
-        let is_post = is_post.unwrap_or(false);
+        let collection = collection.unwrap_or_else(|| "".to_owned());
 
         let permalink = permalink.unwrap_or_else(|| PATH_ALIAS.to_owned());
         let permalink = if !permalink.starts_with('/') {
@@ -391,7 +391,7 @@ impl FrontmatterBuilder {
             format: format.unwrap_or_else(SourceFormat::default),
             layout: layout,
             is_draft: is_draft.unwrap_or(false),
-            is_post: is_post,
+            collection: collection,
             data: data,
         };
 
@@ -423,8 +423,7 @@ pub struct Frontmatter {
     pub format: SourceFormat,
     pub layout: Option<String>,
     pub is_draft: bool,
-    #[serde(skip)]
-    pub is_post: bool,
+    pub collection: String,
     pub data: liquid::Object,
 }
 
@@ -634,7 +633,7 @@ mod test {
             format: Some(SourceFormat::Markdown),
             layout: Some("layout a".to_owned()),
             is_draft: Some(true),
-            is_post: Some(false),
+            collection: Some("pages".to_owned()),
             data: liquid::Object::new(),
         };
         let b = FrontmatterBuilder {
@@ -649,7 +648,7 @@ mod test {
             format: Some(SourceFormat::Raw),
             layout: Some("layout b".to_owned()),
             is_draft: Some(true),
-            is_post: Some(false),
+            collection: Some("posts".to_owned()),
             data: liquid::Object::new(),
         };
 
@@ -677,7 +676,7 @@ mod test {
             format: Some(SourceFormat::Markdown),
             layout: Some("layout a".to_owned()),
             is_draft: Some(true),
-            is_post: Some(false),
+            collection: Some("pages".to_owned()),
             data: liquid::Object::new(),
         };
 
@@ -692,7 +691,7 @@ mod test {
             .merge_format(SourceFormat::Raw)
             .merge_layout("layout b".to_owned())
             .merge_draft(true)
-            .merge_post(false);
+            .merge_collection("posts".to_owned());
         assert_eq!(merge_b_into_a, a);
 
         let merge_empty_into_a = a.clone()
@@ -706,7 +705,7 @@ mod test {
             .merge_format(None)
             .merge_layout(None)
             .merge_draft(None)
-            .merge_post(None);
+            .merge_collection(None);
         assert_eq!(merge_empty_into_a, a);
 
         let merge_a_into_empty = FrontmatterBuilder::new()
@@ -720,7 +719,7 @@ mod test {
             .merge_format(SourceFormat::Markdown)
             .merge_layout("layout a".to_owned())
             .merge_draft(true)
-            .merge_post(false);
+            .merge_collection("pages".to_owned());
         assert_eq!(merge_a_into_empty, a);
     }
 

src/document.rs

@@ -149,15 +149,14 @@ fn document_attributes(front: &cobalt_model::Frontmatter,
              ("categories".to_owned(), categories),
              ("is_draft".to_owned(), liquid::Value::Bool(front.is_draft)),
              ("file".to_owned(), liquid::Value::Object(file)),
+             ("collection".to_owned(), liquid::Value::str(&front.collection)),
              ("data".to_owned(), liquid::Value::Object(front.data.clone()))];
     let mut attributes: liquid::Object = attributes.into_iter().collect();
 
     if let Some(ref published_date) = front.published_date {
         attributes.insert("published_date".to_owned(),
                           liquid::Value::Str(published_date.format()));
     }
-    // TODO(epage): Provide a way to determine tbis
-    attributes.insert("is_post".to_owned(), liquid::Value::Bool(front.is_post));
 
     attributes
 }

src/legacy_model/config.rs

@@ -132,8 +132,7 @@ impl From<GlobalConfig> for cobalt_model::ConfigBuilder {
 
         let default = cobalt_model::FrontmatterBuilder::new()
             .set_excerpt_separator(excerpt_separator)
-            .set_draft(false)
-            .set_post(false);
+            .set_draft(false);
         let posts = cobalt_model::PostBuilder {
             title: None,
             description: None,
@@ -143,8 +142,7 @@ impl From<GlobalConfig> for cobalt_model::ConfigBuilder {
             rss: rss,
             jsonfeed: jsonfeed,
             default: cobalt_model::FrontmatterBuilder::new()
-                .set_permalink(post_path.map(convert_permalink))
-                .set_post(true),
+                .set_permalink(post_path.map(convert_permalink)),
         };
 
         let site = cobalt_model::SiteBuilder {

tests/fixtures/excerpts/_layouts/default.liquid

@@ -1,15 +1,11 @@
 <!DOCTYPE html>
 <html>
     <head>
-        {% if page.is_post %}
-          <title>{{ page.title }}</title>
-        {% else %}
-       	  <title>Cobalt.rs Blog</title>
-        {% endif %}
+        <title>{{ page.title }}</title>
     </head>
     <body>
     <div>
-      {% if page.is_post %}
+      {% if page.collection == "posts" %}
         {% include 'post.liquid' %}
       {% else %}
         {{ page.content }}

tests/fixtures/posts_in_subfolder/_layouts/default.liquid

@@ -2,15 +2,11 @@
 <html>
   <!-- start default.liquid -->
   <head>
-    {% if page.is_post %}
-      <title>{{ page.title }}</title>
-    {% else %}
-       <title>Cobalt.rs Blog</title>
-    {% endif %}
+    <title>{{ page.title }}</title>
   </head>
   <body>
     <div>
-      {% if page.is_post %}
+      {% if page.collection == "posts" %}
         {% include 'post.liquid' %}
       {% else %}
         {{ page.content }}

tests/target/excerpts/index.html

@@ -1,9 +1,7 @@
 <!DOCTYPE html>
 <html>
     <head>
-
-       	  <title>Cobalt.rs Blog</title>
-
+        <title>Index</title>
     </head>
     <body>
     <div>

tests/target/excerpts/posts/post-1.html

@@ -1,9 +1,7 @@
 <!DOCTYPE html>
 <html>
     <head>
-
-          <title>First block is an excerpt</title>
-
+        <title>First block is an excerpt</title>
     </head>
     <body>
     <div>

tests/target/excerpts/posts/post-10.html

@@ -1,9 +1,7 @@
 <!DOCTYPE html>
 <html>
     <head>
-
-          <title>Reference-style links immediately above first block</title>
-
+        <title>Reference-style links immediately above first block</title>
     </head>
     <body>
     <div>

tests/target/excerpts/posts/post-11.html

@@ -1,9 +1,7 @@
 <!DOCTYPE html>
 <html>
     <head>
-
-          <title>Reference-style links immediately below first block do not resolve</title>
-
+        <title>Reference-style links immediately below first block do not resolve</title>
     </head>
     <body>
     <div>

tests/target/excerpts/posts/post-12.html

@@ -1,9 +1,7 @@
 <!DOCTYPE html>
 <html>
     <head>
-
-          <title>Reference-style links in a non-markdown post do not resolve</title>
-
+        <title>Reference-style links in a non-markdown post do not resolve</title>
     </head>
     <body>
     <div>

tests/target/excerpts/posts/post-2.html

@@ -1,9 +1,7 @@
 <!DOCTYPE html>
 <html>
     <head>
-
-          <title>An empty post means an empty excerpt</title>
-
+        <title>An empty post means an empty excerpt</title>
     </head>
     <body>
     <div>

tests/target/excerpts/posts/post-3.html

@@ -1,9 +1,7 @@
 <!DOCTYPE html>
 <html>
     <head>
-
-          <title>Explicit `excerpt`</title>
-
+        <title>Explicit `excerpt`</title>
     </head>
     <body>
     <div>

tests/target/excerpts/posts/post-4.html

@@ -1,9 +1,7 @@
 <!DOCTYPE html>
 <html>
     <head>
-
-          <title>Custom excerpt separator</title>
-
+        <title>Custom excerpt separator</title>
     </head>
     <body>
     <div>

tests/target/excerpts/posts/post-5.html

@@ -1,9 +1,7 @@
 <!DOCTYPE html>
 <html>
     <head>
-
-          <title>Both excerpt and excerpt separator are there</title>
-
+        <title>Both excerpt and excerpt separator are there</title>
     </head>
     <body>
     <div>