Author: lindner
Date: Wed Mar 25 22:58:23 2009
New Revision: 758459
URL: http://svn.apache.org/viewvc?rev=758459&view=rev
Log:
SHINDIG-776 | jslint cleanup of rpc.js
Modified:
incubator/shindig/trunk/features/src/main/javascript/features/rpc/rpc.js
Modified:
incubator/shindig/trunk/features/src/main/javascript/features/rpc/rpc.js
URL:
http://svn.apache.org/viewvc/incubator/shindig/trunk/features/src/main/javascript/features/rpc/rpc.js?rev=758459&r1=758458&r2=758459&view=diff
==============================================================================
--- incubator/shindig/trunk/features/src/main/javascript/features/rpc/rpc.js
(original)
+++ incubator/shindig/trunk/features/src/main/javascript/features/rpc/rpc.js
Wed Mar 25 22:58:23 2009
@@ -16,6 +16,7 @@
* specific language governing permissions and limitations under the License.
*/
+/*global gadgets, console */
/**
* @fileoverview Remote procedure call library for gadget-to-container,
* container-to-gadget, and gadget-to-gadget (thru container) communication.
@@ -183,6 +184,70 @@
'ifpc';
}
+ // Pick the most efficient RPC relay mechanism
+ var relayChannel = getRelayChannel();
+
+ /**
+ * Helper function to process an RPC request
+ * @param {Object} rpc RPC request object
+ * @private
+ */
+ function process(rpc) {
+ //
+ // RPC object contents:
+ // s: Service Name
+ // f: From
+ // c: The callback ID or 0 if none.
+ // a: The arguments for this RPC call.
+ // t: The authentication token.
+ //
+ if (rpc && typeof rpc.s === 'string' && typeof rpc.f === 'string' &&
+ rpc.a instanceof Array) {
+
+ // Validate auth token.
+ if (authToken[rpc.f]) {
+ // We allow type coercion here because all the url params are strings.
+ if (authToken[rpc.f] != rpc.t) {
+ throw new Error("Invalid auth token. " + rpc.f + " vs " + rpc.t);
+ }
+ }
+
+ // If there is a callback for this service, attach a callback function
+ // to the rpc context object for asynchronous rpc services.
+ //
+ // Synchronous rpc request handlers should simply ignore it and return a
+ // value as usual.
+ // Asynchronous rpc request handlers, on the other hand, should pass its
+ // result to this callback function and not return a value on exit.
+ //
+ // For example, the following rpc handler passes the first parameter back
+ // to its rpc client with a one-second delay.
+ //
+ // function asyncRpcHandler(param) {
+ // var me = this;
+ // setTimeout(function() {
+ // me.callback(param);
+ // }, 1000);
+ // }
+ if (rpc.c) {
+ rpc.callback = function(result) {
+ gadgets.rpc.call(rpc.f, CALLBACK_NAME, null, rpc.c, result);
+ };
+ }
+
+ // Call the requested RPC service.
+ var result = (services[rpc.s] ||
+ services[DEFAULT_NAME]).apply(rpc, rpc.a);
+
+ // If the rpc request handler returns a value, immediately pass it back
+ // to the callback. Otherwise, do nothing, assuming that the rpc handler
+ // will make an asynchronous call later.
+ if (rpc.c && typeof result !== 'undefined') {
+ gadgets.rpc.call(rpc.f, CALLBACK_NAME, null, rpc.c, result);
+ }
+ }
+ }
+
/**
* Conducts any initial global work necessary to setup the
* channel type chosen.
@@ -214,7 +279,7 @@
window[NIX_CREATE_CHANNEL] = function(name, channel, token) {
// Verify the authentication token of the gadget trying
// to create a channel for us.
- if (authToken[name] == token) {
+ if (authToken[name] === token) {
nix_channels[name] = channel;
}
};
@@ -298,8 +363,6 @@
}
}
- // Pick the most efficient RPC relay mechanism
- var relayChannel = getRelayChannel();
// Conduct any setup necessary for the chosen channel.
setupChannel();
@@ -328,17 +391,19 @@
* of the channel once they send their first messages.
*/
function setupFrame(frameId, token) {
+ var frame; // used below
+
if (setup[frameId]) {
return;
}
if (relayChannel === 'fe') {
try {
- var frame = document.getElementById(frameId);
+ frame = document.getElementById(frameId);
frame[FE_G2C_CHANNEL] = function(args) {
process(gadgets.json.parse(args));
};
- } catch (e) {
+ } catch (e1) {
// Something went wrong. System will fallback to
// IFPC.
}
@@ -346,10 +411,10 @@
if (relayChannel === 'nix') {
try {
- var frame = document.getElementById(frameId);
+ frame = document.getElementById(frameId);
var wrapper = window[NIX_GET_WRAPPER](frameId, token);
frame.contentWindow.opener = wrapper;
- } catch (e) {
+ } catch (e2) {
// Something went wrong. System will fallback to
// IFPC.
}
@@ -374,64 +439,88 @@
}
/**
- * Helper function to process an RPC request
- * @param {Object} rpc RPC request object
+ * Helper function to emit an invisible IFrame.
+ * @param {String} src SRC attribute of the IFrame to emit.
* @private
*/
- function process(rpc) {
- //
- // RPC object contents:
- // s: Service Name
- // f: From
- // c: The callback ID or 0 if none.
- // a: The arguments for this RPC call.
- // t: The authentication token.
- //
- if (rpc && typeof rpc.s === 'string' && typeof rpc.f === 'string' &&
- rpc.a instanceof Array) {
-
- // Validate auth token.
- if (authToken[rpc.f]) {
- // We allow type coercion here because all the url params are strings.
- if (authToken[rpc.f] != rpc.t) {
- throw new Error("Invalid auth token.");
+ function emitInvisibleIframe(src) {
+ var iframe;
+ // Recycle IFrames
+ for (var i = iframePool.length - 1; i >=0; --i) {
+ var ifr = iframePool[i];
+ try {
+ if (ifr && (ifr.recyclable || ifr.readyState === 'complete')) {
+ ifr.parentNode.removeChild(ifr);
+ if (window.ActiveXObject) {
+ // For MSIE, delete any iframes that are no longer being used. MSIE
+ // cannot reuse the IFRAME because a navigational click sound will
+ // be triggered when we set the SRC attribute.
+ // Other browsers scan the pool for a free iframe to reuse.
+ iframePool[i] = ifr = null;
+ iframePool.splice(i, 1);
+ } else {
+ ifr.recyclable = false;
+ iframe = ifr;
+ break;
+ }
}
+ } catch (e) {
+ // Ignore; IE7 throws an exception when trying to read readyState and
+ // readyState isn't set.
}
+ }
+ // Create IFrame if necessary
+ if (!iframe) {
+ iframe = document.createElement('iframe');
+ iframe.style.border = iframe.style.width = iframe.style.height = '0px';
+ iframe.style.visibility = 'hidden';
+ iframe.style.position = 'absolute';
+ iframe.onload = function() { this.recyclable = true; };
+ iframePool.push(iframe);
+ }
+ iframe.src = src;
+ setTimeout(function() { document.body.appendChild(iframe); }, 0);
+ }
- // If there is a callback for this service, attach a callback function
- // to the rpc context object for asynchronous rpc services.
- //
- // Synchronous rpc request handlers should simply ignore it and return a
- // value as usual.
- // Asynchronous rpc request handlers, on the other hand, should pass its
- // result to this callback function and not return a value on exit.
- //
- // For example, the following rpc handler passes the first parameter back
- // to its rpc client with a one-second delay.
- //
- // function asyncRpcHandler(param) {
- // var me = this;
- // setTimeout(function() {
- // me.callback(param);
- // }, 1000);
- // }
- if (rpc.c) {
- rpc.callback = function(result) {
- gadgets.rpc.call(rpc.f, CALLBACK_NAME, null, rpc.c, result);
- };
- }
-
- // Call the requested RPC service.
- var result = (services[rpc.s] ||
- services[DEFAULT_NAME]).apply(rpc, rpc.a);
+ /**
+ * Conducts an RPC call to the specified
+ * target with the specified data via the IFPC
+ * method.
+ *
+ * @param {String} targetId Module Id of the RPC service provider.
+ * @param {String} serviceName Service name to call.
+ * @param {String} from Module Id of the calling provider.
+ * @param {Object} rpcData The RPC data for this call.
+ * @param {Array.<Object>} callArgs Original arguments to call()
+ */
+ function callIfpc(targetId, serviceName, from, rpcData, callArgs) {
+ // Retrieve the relay file used by IFPC. Note that
+ // this must be set before the call, and so we conduct
+ // an extra check to ensure it is not blank.
+ var relay = gadgets.rpc.getRelayUrl(targetId);
- // If the rpc request handler returns a value, immediately pass it back
- // to the callback. Otherwise, do nothing, assuming that the rpc handler
- // will make an asynchronous call later.
- if (rpc.c && typeof result != 'undefined') {
- gadgets.rpc.call(rpc.f, CALLBACK_NAME, null, rpc.c, result);
+ if (!relay) {
+ if (console && console.log) {
+ console.log('No relay file assigned for IFPC');
}
}
+
+ // The RPC mechanism supports two formats for IFPC (legacy and current).
+ var src = null;
+ if (useLegacyProtocol[targetId]) {
+ // Format: #iframe_id&callId&num_packets&packet_num&block_of_data
+ src = [relay, '#', encodeLegacyData([from, callId, 1, 0,
+ encodeLegacyData([from, serviceName, '', '', from].concat(
+ callArgs))])].join('');
+ } else {
+ // Format: #targetId & sourc...@callid & packetNum & packetId &
packetData
+ src = [relay, '#', targetId, '&', from, '@', callId,
+ '&1&0&', encodeURIComponent(rpcData)].join('');
+ }
+
+ // Conduct the IFPC call by creating the Iframe with
+ // the relay URL and appended message.
+ emitInvisibleIframe(src);
}
/**
@@ -447,7 +536,7 @@
*/
function callNix(targetId, serviceName, from, rpcData) {
try {
- if (from != '..') {
+ if (from !== '..') {
// Call from gadget to the container.
var handler = nix_channels['..'];
@@ -465,7 +554,7 @@
// Create the channel to the parent/container.
// First verify that it knows our auth token to ensure it's not
// an impostor.
- if (handler.GetAuthToken() == authToken['..']) {
+ if (handler.GetAuthToken() === authToken['..']) {
// Auth match - pass it back along with our wrapper to finish.
// own wrapper and our authentication token for co-verification.
var token = authToken['..'];
@@ -514,7 +603,7 @@
*/
function callFrameElement(targetId, serviceName, from, rpcData, callArgs) {
try {
- if (from != '..') {
+ if (from !== '..') {
// Call from gadget to the container.
var fe = window.frameElement;
@@ -551,91 +640,7 @@
callIfpc(targetId, serviceName, from, rpcData, callArgs);
}
- /**
- * Conducts an RPC call to the specified
- * target with the specified data via the IFPC
- * method.
- *
- * @param {String} targetId Module Id of the RPC service provider.
- * @param {String} serviceName Service name to call.
- * @param {String} from Module Id of the calling provider.
- * @param {Object} rpcData The RPC data for this call.
- * @param {Array.<Object>} callArgs Original arguments to call()
- */
- function callIfpc(targetId, serviceName, from, rpcData, callArgs) {
- // Retrieve the relay file used by IFPC. Note that
- // this must be set before the call, and so we conduct
- // an extra check to ensure it is not blank.
- var relay = gadgets.rpc.getRelayUrl(targetId);
-
- if (!relay) {
- if (console && console.log) {
- console.log('No relay file assigned for IFPC');
- }
- }
-
- // The RPC mechanism supports two formats for IFPC (legacy and current).
- var src = null;
- if (useLegacyProtocol[targetId]) {
- // Format: #iframe_id&callId&num_packets&packet_num&block_of_data
- src = [relay, '#', encodeLegacyData([from, callId, 1, 0,
- encodeLegacyData([from, serviceName, '', '', from].concat(
- callArgs))])].join('');
- } else {
- // Format: #targetId & sourc...@callid & packetNum & packetId &
packetData
- src = [relay, '#', targetId, '&', from, '@', callId,
- '&1&0&', encodeURIComponent(rpcData)].join('');
- }
-
- // Conduct the IFPC call by creating the Iframe with
- // the relay URL and appended message.
- emitInvisibleIframe(src);
- }
-
- /**
- * Helper function to emit an invisible IFrame.
- * @param {String} src SRC attribute of the IFrame to emit.
- * @private
- */
- function emitInvisibleIframe(src) {
- var iframe;
- // Recycle IFrames
- for (var i = iframePool.length - 1; i >=0; --i) {
- var ifr = iframePool[i];
- try {
- if (ifr && (ifr.recyclable || ifr.readyState === 'complete')) {
- ifr.parentNode.removeChild(ifr);
- if (window.ActiveXObject) {
- // For MSIE, delete any iframes that are no longer being used. MSIE
- // cannot reuse the IFRAME because a navigational click sound will
- // be triggered when we set the SRC attribute.
- // Other browsers scan the pool for a free iframe to reuse.
- iframePool[i] = ifr = null;
- iframePool.splice(i, 1);
- } else {
- ifr.recyclable = false;
- iframe = ifr;
- break;
- }
- }
- } catch (e) {
- // Ignore; IE7 throws an exception when trying to read readyState and
- // readyState isn't set.
- }
- }
- // Create IFrame if necessary
- if (!iframe) {
- iframe = document.createElement('iframe');
- iframe.style.border = iframe.style.width = iframe.style.height = '0px';
- iframe.style.visibility = 'hidden';
- iframe.style.position = 'absolute';
- iframe.onload = function() { this.recyclable = true; };
- iframePool.push(iframe);
- }
- iframe.src = src;
- setTimeout(function() { document.body.appendChild(iframe); }, 0);
- }
/**
* Attempts to make an rpc by calling the target's receive method directly.
@@ -725,11 +730,11 @@
* @member gadgets.rpc
*/
register: function(serviceName, handler) {
- if (serviceName == CALLBACK_NAME) {
+ if (serviceName === CALLBACK_NAME) {
throw new Error("Cannot overwrite callback service");
}
- if (serviceName == DEFAULT_NAME) {
+ if (serviceName === DEFAULT_NAME) {
throw new Error("Cannot overwrite default service:"
+ " use registerDefault");
}
@@ -744,11 +749,11 @@
* @member gadgets.rpc
*/
unregister: function(serviceName) {
- if (serviceName == CALLBACK_NAME) {
+ if (serviceName === CALLBACK_NAME) {
throw new Error("Cannot delete callback service");
}
- if (serviceName == DEFAULT_NAME) {
+ if (serviceName === DEFAULT_NAME) {
throw new Error("Cannot delete default service:"
+ " use unregisterDefault");
}
