From 6950759eda70391ff76d620c4da812743f7b32e0 Mon Sep 17 00:00:00 2001
From: southerntofu <52931252+southerntofu@users.noreply.github.com>
Date: Wed, 20 Jan 2021 08:24:55 +0000
Subject: [PATCH] Internal links are supported in markdown filter (#1318)

* Internal links are resolved in tera markdown filter (close #1296 #1316)

* Add a test for internal links in markdown filter

Co-authored-by: southerntofu <southerntofu@thunix.net>
---
 CHANGELOG.md                                  |  6 ++++
 components/site/src/tpls.rs                   |  2 +-
 components/templates/src/filters.rs           | 29 ++++++++++++++-----
 .../documentation/templates/overview.md       |  4 +--
 4 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 876bcc3f..05c2cdaa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## unreleased
+
+### Features
+
+- internal links are now resolved in the `markdown` filter in the templates (#1296 #1316)
+
 ## 0.13.0 (2021-01-09)
 
 - Enable HTML minification
diff --git a/components/site/src/tpls.rs b/components/site/src/tpls.rs
index 2b224b57..2e5295ef 100644
--- a/components/site/src/tpls.rs
+++ b/components/site/src/tpls.rs
@@ -50,7 +50,7 @@ pub fn load_tera(path: &Path, config: &Config) -> Result<Tera> {
 
 /// Adds global fns that are to be available to shortcodes while rendering markdown
 pub fn register_early_global_fns(site: &mut Site) {
-    site.tera.register_filter("markdown", filters::MarkdownFilter::new(site.config.clone()));
+    site.tera.register_filter("markdown", filters::MarkdownFilter::new(site.config.clone(), site.permalinks.clone()));
 
     site.tera.register_function(
         "get_url",
diff --git a/components/templates/src/filters.rs b/components/templates/src/filters.rs
index c9b6d6cd..731ecfd2 100644
--- a/components/templates/src/filters.rs
+++ b/components/templates/src/filters.rs
@@ -1,5 +1,6 @@
 use std::collections::HashMap;
 use std::hash::BuildHasher;
+use std::borrow::Cow;
 
 use base64::{decode, encode};
 use config::Config;
@@ -9,17 +10,19 @@ use tera::{to_value, try_get_value, Filter as TeraFilter, Result as TeraResult,
 #[derive(Debug)]
 pub struct MarkdownFilter {
     config: Config,
+    permalinks: HashMap<String, String>,
 }
 
 impl MarkdownFilter {
-    pub fn new(config: Config) -> Self {
-        Self { config }
+    pub fn new(config: Config, permalinks: HashMap<String, String>) -> Self {
+        Self { config, permalinks }
     }
 }
 
 impl TeraFilter for MarkdownFilter {
     fn filter(&self, value: &Value, args: &HashMap<String, Value>) -> TeraResult<Value> {
-        let context = RenderContext::from_config(&self.config);
+        let mut context = RenderContext::from_config(&self.config);
+        context.permalinks = Cow::Borrowed(&self.permalinks);
         let s = try_get_value!("markdown", "value", String, value);
         let inline = match args.get("inline") {
             Some(val) => try_get_value!("markdown", "inline", bool, val),
@@ -69,7 +72,7 @@ mod tests {
 
     #[test]
     fn markdown_filter() {
-        let result = MarkdownFilter::new(Config::default())
+        let result = MarkdownFilter::new(Config::default(), HashMap::new())
             .filter(&to_value(&"# Hey").unwrap(), &HashMap::new());
         assert!(result.is_ok());
         assert_eq!(result.unwrap(), to_value(&"<h1 id=\"hey\">Hey</h1>\n").unwrap());
@@ -79,7 +82,7 @@ mod tests {
     fn markdown_filter_inline() {
         let mut args = HashMap::new();
         args.insert("inline".to_string(), to_value(true).unwrap());
-        let result = MarkdownFilter::new(Config::default()).filter(
+        let result = MarkdownFilter::new(Config::default(), HashMap::new()).filter(
             &to_value(&"Using `map`, `filter`, and `fold` instead of `for`").unwrap(),
             &args,
         );
@@ -92,7 +95,7 @@ mod tests {
     fn markdown_filter_inline_tables() {
         let mut args = HashMap::new();
         args.insert("inline".to_string(), to_value(true).unwrap());
-        let result = MarkdownFilter::new(Config::default()).filter(
+        let result = MarkdownFilter::new(Config::default(), HashMap::new()).filter(
             &to_value(
                 &r#"
 |id|author_id|       timestamp_created|title                 |content           |
@@ -118,16 +121,26 @@ mod tests {
 
         let md = "Hello <https://google.com> :smile: ...";
         let result =
-            MarkdownFilter::new(config.clone()).filter(&to_value(&md).unwrap(), &HashMap::new());
+            MarkdownFilter::new(config.clone(), HashMap::new()).filter(&to_value(&md).unwrap(), &HashMap::new());
         assert!(result.is_ok());
         assert_eq!(result.unwrap(), to_value(&"<p>Hello <a rel=\"noopener\" target=\"_blank\" href=\"https://google.com\">https://google.com</a> 😄 …</p>\n").unwrap());
 
         let md = "```py\ni=0\n```";
-        let result = MarkdownFilter::new(config).filter(&to_value(&md).unwrap(), &HashMap::new());
+        let result = MarkdownFilter::new(config, HashMap::new()).filter(&to_value(&md).unwrap(), &HashMap::new());
         assert!(result.is_ok());
         assert!(result.unwrap().as_str().unwrap().contains("<pre style"));
     }
 
+    #[test]
+    fn mardown_filter_can_use_internal_links() {
+        let mut permalinks = HashMap::new();
+        permalinks.insert("blog/_index.md".to_string(), "/foo/blog".to_string());
+        let md = "Hello. Check out [my blog](@/blog/_index.md)!";
+        let result = MarkdownFilter::new(Config::default(), permalinks).filter(&to_value(&md).unwrap(), &HashMap::new());
+        assert!(result.is_ok());
+        assert_eq!(result.unwrap(), to_value(&"<p>Hello. Check out <a href=\"/foo/blog\">my blog</a>!</p>\n").unwrap());
+    }
+
     #[test]
     fn base64_encode_filter() {
         // from https://tools.ietf.org/html/rfc4648#section-10
diff --git a/docs/content/documentation/templates/overview.md b/docs/content/documentation/templates/overview.md
index 24fc0b5f..5b041980 100644
--- a/docs/content/documentation/templates/overview.md
+++ b/docs/content/documentation/templates/overview.md
@@ -64,9 +64,7 @@ Zola adds a few filters in addition to [those](https://tera.netlify.com/docs/#fi
 in Tera.
 
 ### markdown
-Converts the given variable to HTML using Markdown. This doesn't apply any of the
-features that Zola adds to Markdown; for example, internal links and shortcodes won't work.
-
+Converts the given variable to HTML using Markdown. Shortcodes won't work within this filter.
 By default, the filter will wrap all text in a paragraph. To disable this behaviour, you can
 pass `true` to the inline argument: