Search json index (#1998)

* search: Add support for a JSON index

* docs: Document JSON index for search

* docs: Use lazy-loaded JSON index

* Add elasticlunr prefix to search engine format configuration

This will be useful if support for more search libraries are added in the future

components/config/src/config/search.rs

@@ -1,5 +1,18 @@
 use serde::{Deserialize, Serialize};
 
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "snake_case")]
+pub enum IndexFormat {
+    ElasticlunrJson,
+    ElasticlunrJavascript,
+}
+
+impl Default for IndexFormat {
+    fn default() -> IndexFormat {
+        IndexFormat::ElasticlunrJavascript
+    }
+}
+
 #[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(default)]
 pub struct Search {
@@ -15,6 +28,8 @@ pub struct Search {
     pub include_description: bool,
     /// Include the path of the page in the search index. `false` by default.
     pub include_path: bool,
+    /// Foramt of the search index to be produced. Javascript by default
+    pub index_format: IndexFormat,
 }
 
 impl Default for Search {
@@ -25,6 +40,7 @@ impl Default for Search {
             include_description: false,
             include_path: false,
             truncate_content_length: None,
+            index_format: Default::default(),
         }
     }
 }

components/config/src/lib.rs

@@ -5,8 +5,13 @@ mod theme;
 use std::path::Path;
 
 pub use crate::config::{
-    languages::LanguageOptions, link_checker::LinkChecker, link_checker::LinkCheckerLevel,
+    languages::LanguageOptions,
-    search::Search, slugify::Slugify, taxonomies::TaxonomyConfig, Config,
+    link_checker::LinkChecker,
+    link_checker::LinkCheckerLevel,
+    search::{IndexFormat, Search},
+    slugify::Slugify,
+    taxonomies::TaxonomyConfig,
+    Config,
 };
 use errors::Result;
 

components/site/src/lib.rs

@@ -15,7 +15,7 @@ use libs::rayon::prelude::*;
 use libs::tera::{Context, Tera};
 use libs::walkdir::{DirEntry, WalkDir};
 
-use config::{get_config, Config};
+use config::{get_config, Config, IndexFormat};
 use content::{Library, Page, Paginator, Section, Taxonomy};
 use errors::{anyhow, bail, Context as ErrorContext, Result};
 use libs::relative_path::RelativePathBuf;
@@ -764,32 +764,36 @@ impl Site {
         Ok(())
     }
 
+    fn index_for_lang(&self, lang: &str) -> Result<()> {
+        let index_json = search::build_index(
+            &self.config.default_language,
+            &self.library.read().unwrap(),
+            &self.config,
+        )?;
+        let (path, content) = match &self.config.search.index_format {
+            IndexFormat::ElasticlunrJson => {
+                let path = self.output_path.join(&format!("search_index.{}.json", lang));
+                (path, index_json)
+            }
+            IndexFormat::ElasticlunrJavascript => {
+                let path = self.output_path.join(&format!("search_index.{}.js", lang));
+                let content = format!("window.searchIndex = {};", index_json);
+                (path, content)
+            }
+        };
+        create_file(&path, &content)
+    }
+
     pub fn build_search_index(&self) -> Result<()> {
         ensure_directory_exists(&self.output_path)?;
         // TODO: add those to the SITE_CONTENT map
 
         // index first
-        create_file(
+        self.index_for_lang(&self.config.default_language)?;
-            &self.output_path.join(&format!("search_index.{}.js", self.config.default_language)),
-            &format!(
-                "window.searchIndex = {};",
-                search::build_index(
-                    &self.config.default_language,
-                    &self.library.read().unwrap(),
-                    &self.config
-                )?
-            ),
-        )?;
 
         for (code, language) in &self.config.other_languages() {
             if code != &self.config.default_language && language.build_search_index {
-                create_file(
+                self.index_for_lang(code)?;
-                    &self.output_path.join(&format!("search_index.{}.js", &code)),
-                    &format!(
-                        "window.searchIndex = {};",
-                        search::build_index(code, &self.library.read().unwrap(), &self.config)?
-                    ),
-                )?;
             }
         }
 

docs/config.toml

@@ -5,6 +5,9 @@ description = "Everything you need to make a static site engine in one binary."
 compile_sass = true
 build_search_index = true
 
+[search]
+index_format = "elasticlunr_json"
+
 [markdown]
 highlight_code = true
 highlight_theme = "kronuz"

docs/content/documentation/content/search.md

@@ -17,6 +17,9 @@ After `zola build` or `zola serve`, you should see two files in your public dire
 - `search_index.${default_language}.js`: so `search_index.en.js` for a default setup
 - `elasticlunr.min.js`
 
+If you set `index_format = "elasticlunr_json"` in your `config.toml`, a `search_index.${default_language}.json` is generated
+instead of the default `search_index.${default_language}.js`.
+
 As each site will be different, Zola makes no assumptions about your search function and doesn't provide
 the JavaScript/CSS code to do an actual search and display results. You can look at how this site
 implements it to get an idea: [search.js](https://github.com/getzola/zola/tree/master/docs/static/search.js).

docs/content/documentation/getting-started/configuration.md

@@ -160,6 +160,10 @@ include_content = true
 # become too big to load on the site. Defaults to not being set.
 # truncate_content_length = 100
 
+# Wether to produce the search index as a javascript file or as a JSON file
+# Accepted value "elasticlunr_javascript" or "elasticlunr_json"
+index_format = "elasticlunr_javascript"
+
 # Optional translation object for the default language
 # Example:
 #     default_language = "fr"

docs/static/search.js

@@ -142,11 +142,24 @@ function initSearch() {
     }
   };
   var currentTerm = "";
-  var index = elasticlunr.Index.load(window.searchIndex);
+  var index;
+  
+  var initIndex = async function () {
+    if (index === undefined) {
+      index = fetch("/search_index.en.json")
+        .then(
+          async function(response) {
+            return await elasticlunr.Index.load(await response.json());
+        }
+      );
+    }
+    let res = await index;
+    return res;
+  }
 
-  $searchInput.addEventListener("keyup", debounce(function() {
+  $searchInput.addEventListener("keyup", debounce(async function() {
     var term = $searchInput.value.trim();
-    if (term === currentTerm || !index) {
+    if (term === currentTerm) {
       return;
     }
     $searchResults.style.display = term === "" ? "none" : "block";
@@ -156,7 +169,7 @@ function initSearch() {
       return;
     }
 
-    var results = index.search(term, options);
+    var results = (await initIndex()).search(term, options);
     if (results.length === 0) {
       $searchResults.style.display = "none";
       return;

docs/templates/index.html

@@ -103,7 +103,6 @@
         </footer>
 
         <script type="text/javascript" src="{{ get_url(path="elasticlunr.min.js") }}"></script>
-        <script type="text/javascript" src="{{ get_url(path="search_index.en.js") }}"></script>
         <script type="text/javascript" src="{{ get_url(path="search.js") }}"></script>
     </body>
 </html>