From 66012257388eb5d28a3217afe867ad0c636c5bdb Mon Sep 17 00:00:00 2001
From: Brad Fitzpatrick <brad@danga.com>
Date: Sat, 16 Apr 2011 16:18:31 -0700
Subject: [PATCH] camlistored Javascript discovery

---
 server/go/camlistored/ui.go    | 37 ++++++++++++++++++++++++++--------
 server/go/camlistored/ui/ui.js | 28 ++++++++++++++++++++++++-
 2 files changed, 56 insertions(+), 9 deletions(-)

diff --git a/server/go/camlistored/ui.go b/server/go/camlistored/ui.go
index ffb81dd80..a7ec095e3 100644
--- a/server/go/camlistored/ui.go
+++ b/server/go/camlistored/ui.go
@@ -19,6 +19,7 @@ package main
 import (
 	"fmt"
 	"http"
+	"json"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -60,12 +61,32 @@ func createUIHandler(conf jsonconfig.Obj) (h http.Handler, err os.Error) {
 	return ui, nil
 }
 
-func (ui *UIHandler) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
-	file := staticFilePattern.FindString(req.URL.Path)
-	if file != "" {
-		file = file[1:]
-	} else {
-		file = "index.html"
-	}
-	http.ServeFile(rw, req, filepath.Join(ui.FilesDir, file))
+func wantsDiscovery(req *http.Request) bool {
+	return req.Method == "GET" &&
+		(req.Header.Get("Accept") == "text/x-camli-configuration" ||
+		req.FormValue("camli.mode") == "config")
+}
+
+func (ui *UIHandler) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
+	rw.Header().Set("Vary", "Accept")
+	switch {
+	case wantsDiscovery(req):
+		ui.serveDiscovery(rw)
+	default:
+		file := staticFilePattern.FindString(req.URL.Path)
+		if file != "" {
+			file = file[1:]
+		} else {
+			file = "index.html"
+		}
+		http.ServeFile(rw, req, filepath.Join(ui.FilesDir, file))
+	}
+}
+
+func (ui *UIHandler) serveDiscovery(rw http.ResponseWriter) {
+	rw.Header().Set("Content-Type", "text/javascript")
+	json.NewEncoder(rw).Encode(map[string]interface{}{
+		"blobRoot": ui.BlobRoot,
+		"searchRoot": ui.SearchRoot,
+	})
 }
diff --git a/server/go/camlistored/ui/ui.js b/server/go/camlistored/ui/ui.js
index 248db515f..c9c5dedf6 100644
--- a/server/go/camlistored/ui/ui.js
+++ b/server/go/camlistored/ui/ui.js
@@ -1,3 +1,29 @@
+/*
+Copyright 2011 Google Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
 function discover() {
-         alert("TODO: discovery");
+    var xhr = new XMLHttpRequest();
+    xhr.onreadystatechange = function() {
+        if (xhr.readyState != 4) { return; }
+        if (xhr.status != 200) {
+            console.log("no status 200; got " + xhr.status);
+        }
+        var disco = JSON.parse(xhr.responseText);
+        alert(JSON.stringify(disco));
+    };
+    xhr.open("GET", "./?camli.mode=config", true);
+    xhr.send();
 }