HTML5 postMessage is not good

• Download the addon here or download it from mozilla webiste
• test page this page is listening msg with name "cmd"
• If you want to check its source code

User manual

To web designers:
you have to test whether your users have install this.
var installed=window.MSG!==undefined;
if false, then you will have to suggest your users to install this.

It's better not to take this addon to your name. If you do, I guess your users might suspect your accountability.
While I am the 3rd party to you & your users, so more trustable.



window.MSG.post(msgdata, arrayOfDomainTarget, arrayOfWindowIDTarget)

this 'window' can be omit, not similar to the one specified in HTML5
there you need an window object.
Here, you do not. this 'window' just indicate MSG is in the global space.


msgname is the the name the message category.
msgdata is a JSON object. it will be stringified before post
arrayOfDomainTarget, arrayOfWindowIDTarget
        I use logical AND. originally it was OR
        later I changed it to AND. more appropriate. I guess.
        and I let "*" to be the wildcard for all windowID.

the caller's information does not present in the parameter at all
 since the browser knows all the information.
so we can see that this method does not allow the sender to fool the receiver.

the sender just call as follows.

   window.name="randomGeneratedWindowID";
   MSG.post({what:'do thing abc',parameter:'the value of a parameter'},["jackiszhp.info"],[*]);

for the receiver, 2 things.


   //#1 define the message handler
   function messageHandler(e){
   var obj=JSON.parse(e.detail);
   obj.name is the msgname === 'msgpost'  fixed
   obj.data is the msgdata = {what:'fuck',who:'not to tell'};
   obj.source  is the sender
   obj.source.href  is the sender's window.location.href
   obj.source.WID  is the sender's window.name, i.e. 'randomGeneratedWindowID'
   obj.target  is the target of this event
   obj.target.domains  is the target domains of this event
   obj.target.WIDs  is the target WIDs of this event
   ....
   }
   //#2 register the message handler
   window.addEventListener(msgname, messageHandler,false);
   or
   document.addEventListener(msgname, messageHandler,false);
while msgname==="msgpost" fixed.

   //to respond
   window.name="here another windowID";
   var hostname=getHostname(obj.source.href);
   MSG.post({what:'do thing defg',parameter:'the value of a parameter'},[hostname],[obj.source.WID]);



Additional note:
#A. window can be uniquely identified.
    but here, I did not use it.
    I use window.name instead.
     https://developer.mozilla.org/en-US/docs/Code_snippets/Windows#Uniquely_identifying_DOM_windows
#B. I hope the mozilla can take my interface and include it into the firefox.



    

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