docs: add advanced search capabilities

Allow targetting the search scope to the website, wiki or mailing lists
only. When javascript is disabled this should gracefully fallback to
only searching the website.

Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

docs/js/main.js

@@ -22,4 +22,56 @@ function pageload() {
             }
         }
     });
+
+    /* Setting this class makes the advanced search options visible */
+    advancedSearch = document.getElementById("advancedsearch")
+    advancedSearch.className = "advancedsearch"
+
+    simpleSearch = document.getElementById("simplesearch")
+    simplesearch.addEventListener("submit", advancedsearch)
+}
+
+function advancedsearch(e) {
+    e.preventDefault();
+    e.stopPropagation();
+
+    form = document.createElement("form");
+    form.setAttribute("method", "get");
+
+    newq = document.createElement("input");
+    newq.setAttribute("type", "hidden");
+    form.appendChild(newq);
+
+    q = document.getElementById("searchq");
+    whats = document.getElementsByName("what");
+    what = "website";
+    for (var i = 0; i < whats.length; i++) {
+        if (whats[i].checked) {
+            what = whats[i].value;
+            break;
+        }
+    }
+
+    if (what == "website") {
+        form.setAttribute("action", "https://google.com/search");
+        newq.setAttribute("name", "q");
+        newq.value = "site:libvirt.org " + q.value;
+    } else if (what == "wiki") {
+        form.setAttribute("action", "https://wiki.libvirt.org/index.php");
+        newq.setAttribute("name", "search");
+        newq.value = q.value;
+    } else if (what == "devs") {
+        form.setAttribute("action", "https://google.com/search");
+        newq.setAttribute("name", "q");
+        newq.value = "site:redhat.com/archives/libvir-list " + q.value;
+    } else if (what == "users") {
+        form.setAttribute("action", "https://google.com/search");
+        newq.setAttribute("name", "q");
+        newq.value = "site:redhat.com/archives/libvirt-users " + q.value;
+    }
+
+    document.body.appendChild(form);
+    form.submit();
+
+    return false;
 }