[tor-commits] [flashproxy/master] Add flashproxy.js.

[dcf at torproject.org]

commit 038c8f7c215ea1fcf32c61cd76f0ff80f4bb7990
Author: David Fifield <david at bamsoftware.com>
Date:   Sun Oct 16 19:12:11 2011 -0700

    Add flashproxy.js.
    
    This is a file that will be hosted at crypto.stanford.edu to make it
    easy to install the badge on a web page.
    
    This script also does the User-Agent detection (to politely disable
    itself for cell phones) that was formerly done by swfcat itself.
---
 README        |   12 +++---
 flashproxy.js |  141 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 147 insertions(+), 6 deletions(-)

diff --git a/README b/README
index 1a49686..6db4ee0 100644
--- a/README
+++ b/README
@@ -150,13 +150,13 @@ wait a few minutes. It can take a while to download relay descriptors.
 
 == How to put a flash proxy badge on a web page.
 
-Copy swfcat.swf to your server, then paste in this HTML:
+Copy swfcat.swf to your server, then paste in this HTML where you want
+the badge to appear:
+
+<script type="text/javascript" src="https://crypto.stanford.edu/flashproxy/flashproxy.js"></script>
+
+It will be inserted as a span element with the id "flashproxy-badge".
 
-<object width="70" height="23">
-	<param name="movie" value="swfcat.swf">
-	<param name="flashvars" value="">
-	<embed src="swfcat.swf" width="70" height="23" flashvars=""></embed>
-</object>
 
 == For developers
 
diff --git a/flashproxy.js b/flashproxy.js
new file mode 100644
index 0000000..fea72f9
--- /dev/null
+++ b/flashproxy.js
@@ -0,0 +1,141 @@
+/* Are circumstances such that we should self-disable and not be a
+   proxy? We take a best-effort guess as to whether this device runs on
+   a battery or the data transfer might be expensive.
+
+   Matching mobile User-Agents is complex; but we only need to match
+   those devices that can also run a recent version of Adobe Flash,
+   which is a subset of this list:
+   https://secure.wikimedia.org/wikipedia/en/wiki/Adobe_Flash_Player#Mobile_operating_systems
+
+   Other resources:
+   http://www.zytrax.com/tech/web/mobile_ids.html
+   http://googlewebmastercentral.blogspot.com/2011/03/mo-better-to-also-detect-mobile-user.html
+   http://search.cpan.org/~cmanley/Mobile-UserAgent-1.05/lib/Mobile/UserAgent.pm
+*/
+function flashproxy_should_disable()
+{
+    var ua;
+
+    ua = window.navigator.userAgent;
+    if (ua != null) {
+        const UA_LIST = [
+            /\bmobile\b/i,
+            /\bandroid\b/i,
+            /\bopera mobi\b/i,
+        ];
+
+        for (var i = 0; i < UA_LIST.length; i++) {
+            var re = UA_LIST[i];
+
+            if (ua.match(re)) {
+                return true;
+            }
+        }
+    }
+
+    return false;
+}
+
+/* Create and return a DOM fragment:
+<span id=BADGE_ID>
+<a href=FLASHPROXY_INFO_URL>
+    child
+</a>
+</span>
+*/
+function flashproxy_make_container(child)
+{
+    const BADGE_ID = "flashproxy-badge";
+    const FLASHPROXY_INFO_URL = "https://crypto.stanford.edu/flashproxy/";
+
+    var container;
+    var a;
+
+    container = document.createElement("span");
+    container.setAttribute("id", "flashproxy-badge");
+    a = document.createElement("a");
+    a.setAttribute("href", FLASHPROXY_INFO_URL);
+    a.appendChild(child)
+    container.appendChild(a);
+
+    return container;
+}
+
+/* Create and return a DOM fragment:
+<object width=WIDTH height=HEIGHT>
+    <param name="movie" value=SWFCAT_URL>
+    <param name="flashvars" value=FLASHVARS>
+    <embed src=SWFCAT_URL width=WIDTH height=HEIGHT flashvars=FLASHVARS></embed>
+</object>
+*/
+function flashproxy_make_badge()
+{
+    const WIDTH = 70;
+    const HEIGHT = 23;
+    const FLASHVARS = "";
+    const SWFCAT_URL = "https://crypto.stanford.edu/flashproxy/swfcat.swf";
+
+    var object;
+    var param;
+    var embed;
+
+    object = document.createElement("object");
+    object.setAttribute("width", WIDTH);
+    object.setAttribute("height", HEIGHT);
+
+    param = document.createElement("param");
+    param.setAttribute("name", "movie");
+    param.setAttribute("value", SWFCAT_URL);
+    object.appendChild(param);
+    param = document.createElement("param");
+    param.setAttribute("name", "flashvars");
+    param.setAttribute("value", FLASHVARS);
+    object.appendChild(param);
+
+    embed = document.createElement("embed");
+    embed.setAttribute("src", SWFCAT_URL);
+    embed.setAttribute("width", WIDTH);
+    embed.setAttribute("height", HEIGHT);
+    embed.setAttribute("flashvars", FLASHVARS);
+    object.appendChild(embed);
+
+    return object;
+}
+
+/* Create and return a non-functional placeholder badge DOM fragment:
+   <img src=BADGE_IMAGE_URL border="0">
+*/
+function flashproxy_make_dummy_badge()
+{
+    const BADGE_IMAGE_URL = "https://crypto.stanford.edu/flashproxy/badge.png";
+
+    var img;
+
+    img = document.createElement("img");
+    img.setAttribute("src", BADGE_IMAGE_URL);
+    img.setAttribute("border", 0);
+
+    return img;
+}
+
+function flashproxy_badge_insert()
+{
+    var badge;
+    var e;
+
+    if (flashproxy_should_disable()) {
+        badge = flashproxy_make_dummy_badge();
+    } else {
+        badge = flashproxy_make_badge();
+    }
+
+    /* http://intertwingly.net/blog/2006/11/10/Thats-Not-Write for this trick to
+       insert right after the <script> element in the DOM. */
+    e = document;
+    while (e.lastChild && e.lastChild.nodeType == 1) {
+        e = e.lastChild;
+    }
+    e.parentNode.appendChild(flashproxy_make_container(badge));
+}
+
+flashproxy_badge_insert();