js/kunai.js: crsearch.jsonの位置を自動で特定

js/kunai.js

@@ -116,10 +116,57 @@ class Kunai {
 
     await this.initSidebar()
 
+    // Dynamically set the base_url
+    const dynamic_base_url = (() => {
+      // Determine the location of the website base
+      const current_script = document.currentScript || document.querySelector('script[src*="static/kunai/js/kunai.js"]');
+      if (current_script) {
+        // Try to determine the base_url based on the location of this script
+        // ({base_url}/static/kunai/js/kunai.js).
+        const url_kunai = current_script.getAttribute("src");
+        const url = url_kunai.replace(/\bstatic\/kunai\/js\/kunai\.js([?#].*)?$/, "");
+        if (url != url_kunai) return url == "" ? "/" : url;
+      }
+      // Fallback case assuming that the website is hosted at the top level
+      return "/";
+    })();
+
+    const url_database = (() => {
+      // Determine the location of the database file "crsearch.json".
+      const current_script = document.currentScript || document.querySelector('script[src*="kunai/js/kunai.js"]');
+      if (current_script) {
+        // Try to download crsearch.json from the project website for the local
+        // HTML files.  When a HTML in the local file system is directly opened
+        // in a Web browser, "static/crsearch/crsearch.json" cannot be read
+        // through XHR due to the CORS (cross-origin resource sharing) policy
+        // for the local files.  We instead try to download "crsearch.json"
+        // from the project website, which are assumed to be stored in <meta name="twietter:url"
+        // content="..." /> or in <meta property="og:url" content="..." />.
+        if (/^file:\/\//.test(current_script.src)) {
+          const meta = document.querySelector('meta[name="twitter:url"]') || document.querySelector('meta[property="og:url"]');
+          if (meta && meta.content) {
+            const m = meta.content.toString().match(/^https?:\/\/[^/]*\//);
+            if (m) return m[0] + "static/crsearch/crsearch.json";
+          }
+        }
+
+        // Try to determine the position of crsearch.json
+        // ({base_url}/static/crsearch/crsearch.json) based on the location of
+        // this script ({base_url}/static/kunai/js/kunai.js).
+        const url_kunai = current_script.getAttribute("src");
+        const url = url_kunai.replace(/\bkunai\/js\/kunai\.js([?#].*)?$/, "crsearch/crsearch.json");
+        if (url != url_kunai) return url;
+      }
+
+      // Fallback case assuming that the website is hosted at the top level
+      return "/static/crsearch/crsearch.json";
+    })();
+
     let crs = new CRSearch({
       onDatabase: this.onDatabase.bind(this),
+      base_url: dynamic_base_url
     })
-    crs.database('/static/crsearch/crsearch.json')
+    crs.database(url_database);
 
     let e = $('.crsearch')
     await crs.searchbox(e)