1 files changed, 99 insertions, 0 deletions
diff --git a/packages/gitbook-plugin-lunr/index.js b/packages/gitbook-plugin-lunr/index.js
new file mode 100644
index 0000000..bdde8f6
--- /dev/null
+++ b/packages/gitbook-plugin-lunr/index.js
@@ -0,0 +1,99 @@
+/* eslint-disable no-var, object-shorthand */
+var lunr = require('lunr');
+var Entities = require('html-entities').AllHtmlEntities;
+
+var Html = new Entities();
+
+var searchIndex;
+
+// Called with the `this` context provided by Gitbook
+function getSearchIndex(context) {
+    if (!searchIndex) {
+        // Create search index
+        var ignoreSpecialCharacters = (
+            context.config.get('pluginsConfig.lunr.ignoreSpecialCharacters')
+            || context.config.get('lunr.ignoreSpecialCharacters')
+        );
+
+        searchIndex = lunr(function() {
+            this.ref('url');
+
+            this.field('title', { boost: 10 });
+            this.field('keywords', { boost: 15 });
+            this.field('body');
+
+            if (!ignoreSpecialCharacters) {
+                // Don't trim non words characters (to allow search such as "C++")
+                this.pipeline.remove(lunr.trimmer);
+            }
+        });
+    }
+    return searchIndex;
+}
+
+// Map of Lunr ref to document
+var documentsStore = {};
+
+var searchIndexEnabled = true;
+var indexSize = 0;
+
+module.exports = {
+    hooks: {
+        // Index each page
+        'page': function(page) {
+            const search = page.attributes.search;
+
+            if (this.output.name != 'website' || !searchIndexEnabled || search === false) {
+                return page;
+            }
+
+            var text, maxIndexSize;
+            maxIndexSize = this.config.get('pluginsConfig.lunr.maxIndexSize') || this.config.get('lunr.maxIndexSize');
+
+            this.log.debug.ln('index page', page.path);
+
+            text = page.content;
+            // Decode HTML
+            text = Html.decode(text);
+            // Strip HTML tags
+            text = text.replace(/(<([^>]+)>)/ig, '');
+
+            indexSize = indexSize + text.length;
+            if (indexSize > maxIndexSize) {
+                this.log.warn.ln('search index is too big, indexing is now disabled');
+                searchIndexEnabled = false;
+                return page;
+            }
+
+            var keywords = [];
+            if (search) {
+                keywords = search.keywords || [];
+            }
+
+            // Add to index
+            var doc = {
+                url: this.output.toURL(page.path),
+                title: page.title,
+                summary: page.description,
+                keywords: keywords.join(' '),
+                body: text
+            };
+
+            documentsStore[doc.url] = doc;
+            getSearchIndex(this).add(doc);
+
+            return page;
+        },
+
+        // Write index to disk
+        'finish': function() {
+            if (this.output.name != 'website') return;
+
+            this.log.debug.ln('write search index');
+            return this.output.writeFile('search_index.json', JSON.stringify({
+                index: getSearchIndex(this),
+                store: documentsStore
+            }));
+        }
+    }
+};