From 6a059d86d0f0396e9ebf9e85c9bd925fb01f6ec1 Mon Sep 17 00:00:00 2001
From: Vincent Prouillet <vincent@wearewizards.io>
Date: Fri, 16 Jun 2017 23:09:01 +0900
Subject: [PATCH] Add aliases to pages. Fix #86

---
 CHANGELOG.md                          |  2 ++
 README.md                             |  1 +
 src/front_matter/page.rs              |  4 ++++
 src/site.rs                           | 21 +++++++++++++++++++++
 test_site/content/posts/fixed-slug.md |  1 +
 tests/site.rs                         |  4 ++++
 6 files changed, 33 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c2948db7..4114eea3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,8 @@
 - Add `section` to a page Tera context if there is one
 - Reverse `order` sorting to be more intuitive: they are now desc, think of them
 as 1st, 2nd in the list
+- Add `aliases` to pages for when you are changing urls but want to redirect
+to the new one
 
 ## 0.0.6 (2017-05-24)
 
diff --git a/README.md b/README.md
index f26e0f12..d64f9800 100644
--- a/README.md
+++ b/README.md
@@ -91,6 +91,7 @@ A front-matter has only optional variables:
 - category: only one category is allowed
 - draft: whether the post is a draft or not
 - template: if you want to change the template used to render that specific page
+- aliases: which URL to redirect to the new: useful when you changed a page URL and don't want to 404
 
 Even if your front-matter is empty, you will need to put the `+++`.
 You can also, like in the config, add your own variables in a `[extra]` table.
diff --git a/src/front_matter/page.rs b/src/front_matter/page.rs
index 9613c8fe..67a1c9e5 100644
--- a/src/front_matter/page.rs
+++ b/src/front_matter/page.rs
@@ -28,6 +28,9 @@ pub struct PageFrontMatter {
     pub category: Option<String>,
     /// Integer to use to order content. Lowest is at the bottom, highest first
     pub order: Option<usize>,
+    /// All aliases for that page. Gutenberg will create HTML templates that will
+    #[serde(skip_serializing)]
+    pub aliases: Option<Vec<String>>,
     /// Specify a template different from `page.html` to use for that page
     #[serde(skip_serializing)]
     pub template: Option<String>,
@@ -100,6 +103,7 @@ impl Default for PageFrontMatter {
             tags: None,
             category: None,
             order: None,
+            aliases: None,
             template: None,
             extra: None,
         }
diff --git a/src/site.rs b/src/site.rs
index 2e7fec71..cfdba8b0 100644
--- a/src/site.rs
+++ b/src/site.rs
@@ -337,6 +337,8 @@ impl Site {
     /// Deletes the `public` directory and builds the site
     pub fn build(&self) -> Result<()> {
         self.clean()?;
+        // Render aliases first to allow overwriting
+        self.render_aliases()?;
         self.render_sections()?;
         self.render_orphan_pages()?;
         self.render_sitemap()?;
@@ -352,6 +354,25 @@ impl Site {
         self.copy_static_directory()
     }
 
+    pub fn render_aliases(&self) -> Result<()> {
+        for page in self.pages.values() {
+            if let Some(ref aliases) = page.meta.aliases {
+                for alias in aliases {
+                    let mut output_path = self.output_path.to_path_buf();
+                    for component in alias.split("/") {
+                        output_path.push(&component);
+
+                        if !output_path.exists() {
+                            create_directory(&output_path)?;
+                        }
+                    }
+                    create_file(&output_path.join("index.html"), &render_redirect_template(&page.permalink, &self.tera)?)?;
+                }
+            }
+        }
+        Ok(())
+    }
+
     /// Renders robots.txt
     pub fn render_robots(&self) -> Result<()> {
         ensure_directory_exists(&self.output_path)?;
diff --git a/test_site/content/posts/fixed-slug.md b/test_site/content/posts/fixed-slug.md
index f28cfc37..ccba64a7 100644
--- a/test_site/content/posts/fixed-slug.md
+++ b/test_site/content/posts/fixed-slug.md
@@ -3,6 +3,7 @@ title = "Fixed slug"
 description = ""
 slug = "something-else"
 date = "2017-01-01"
+aliases = ["/an-old-url/old-page"]
 +++
 
 A simple page with a slug defined
diff --git a/tests/site.rs b/tests/site.rs
index b6502024..d247fd5a 100644
--- a/tests/site.rs
+++ b/tests/site.rs
@@ -118,6 +118,10 @@ fn can_build_site_without_live_reload() {
     assert!(file_exists!(public, "posts/tutorials/programming/index.html"));
     // TODO: add assertion for syntax highlighting
 
+    // aliases work
+    assert!(file_exists!(public, "an-old-url/old-page/index.html"));
+    assert!(file_contains!(public, "an-old-url/old-page/index.html", "something-else"));
+
     // No tags or categories
     assert_eq!(file_exists!(public, "categories/index.html"), false);
     assert_eq!(file_exists!(public, "tags/index.html"), false);