Easy-to-follow video tutorials help you learn software, creative, and business skills.Become a member

An interactive example

From: HTML5: Messaging and Communications in Depth

Video: An interactive example

Now let's take a look at a more interactive example of cross-origin messaging. This is a little chat app, and while it may not be terribly useful to chat between two windows on a single desktop, it does give us an opportunity to explore some of the subtleties of the messaging interface. So this application works much like the ones that we've seen so far; in fact it uses a lot of the same code. The first thing that it does is it loads up the second window inside a frame, and then the second window inside a frame sends a message back to the first window to tell it that it's loaded.

An interactive example

Now let's take a look at a more interactive example of cross-origin messaging. This is a little chat app, and while it may not be terribly useful to chat between two windows on a single desktop, it does give us an opportunity to explore some of the subtleties of the messaging interface. So this application works much like the ones that we've seen so far; in fact it uses a lot of the same code. The first thing that it does is it loads up the second window inside a frame, and then the second window inside a frame sends a message back to the first window to tell it that it's loaded.

So you'll see in the first window, which is the outer one, we have this log "this is windowOne" and its host, one.3sn.net. And windowTwo is on two.3sn.net so they are in different origins. And then once windowTwo gets loaded, it sends this message to windowOne that says, "windowTwo is loaded." And the purpose of that is so that windowOne now has a handle to windowTwo's window object or rather, a window proxy object that works just like its window object. You'll also notice that it says info, and the reason for that is that we're actually sending some structured data that categorizes the different types of messages.

And we have two different types of messages: we have info message and we have chat messages. So when I come up here and I type a message, a chat message, you'll see that that message shows up over here without saying info in front of it. And if I send one over here, you see that it comes up over here without it saying info in front of it. And the reason for that is that there are actually two different categories of messages that are being sent, and it's being sent as structured data with JSON.

And the reason we're using JSON is because this application worked just fine with the structured data except on the Internet Explorer. And in order to for it to work on Internet Explorer, we had to use JSON, because Internet Explorer is only sending strings in its data payload. So now that we've seen how the app works, in the next movie we'll take a look at the code and see how it's implemented.

Show transcript

This video is part of

Image for HTML5: Messaging and Communications in Depth
HTML5: Messaging and Communications in Depth

11 video lessons · 5795 viewers

Bill Weinman
Author

 

Start learning today

Get unlimited access to all courses for just $25/month.

Become a member
Sometimes @lynda teaches me how to use a program and sometimes Lynda.com changes my life forever. @JosefShutter
@lynda lynda.com is an absolute life saver when it comes to learning todays software. Definitely recommend it! #higherlearning @Michael_Caraway
@lynda The best thing online! Your database of courses is great! To the mark and very helpful. Thanks! @ru22more
Got to create something yesterday I never thought I could do. #thanks @lynda @Ngventurella
I really do love @lynda as a learning platform. Never stop learning and developing, it’s probably our greatest gift as a species! @soundslikedavid
@lynda just subscribed to lynda.com all I can say its brilliant join now trust me @ButchSamurai
@lynda is an awesome resource. The membership is priceless if you take advantage of it. @diabetic_techie
One of the best decision I made this year. Buy a 1yr subscription to @lynda @cybercaptive
guys lynda.com (@lynda) is the best. So far I’ve learned Java, principles of OO programming, and now learning about MS project @lucasmitchell
Signed back up to @lynda dot com. I’ve missed it!! Proper geeking out right now! #timetolearn #geek @JayGodbold
Share a link to this course

What are exercise files?

Exercise files are the same files the author uses in the course. Save time by downloading the author's files instead of setting up your own files, and learn by following along with the instructor.

Can I take this course without the exercise files?

Yes! If you decide you would like the exercise files later, you can upgrade to a premium account any time.

Become a member Download sample files See plans and pricing

Please wait... please wait ...
Upgrade to get access to exercise files.

Exercise files video

How to use exercise files.

Learn by watching, listening, and doing, Exercise files are the same files the author uses in the course, so you can download them and follow along Premium memberships include access to all exercise files in the library.


Exercise files

Exercise files video

How to use exercise files.

For additional information on downloading and using exercise files, watch our instructional video or read the instructions in the FAQ .

This course includes free exercise files, so you can practice while you watch the course. To access all the exercise files in our library, become a Premium Member.

Join now Already a member? Log in

Are you sure you want to mark all the videos in this course as unwatched?

This will not affect your course history, your reports, or your certificates of completion for this course.


Mark all as unwatched Cancel

Congratulations

You have completed HTML5: Messaging and Communications in Depth.

Return to your organization's learning portal to continue training, or close this page.


OK
Become a member to add this course to a playlist

Join today and get unlimited access to the entire library of video courses—and create as many playlists as you like.

Get started

Already a member ?

Become a member to like this course.

Join today and get unlimited access to the entire library of video courses.

Get started

Already a member?

Exercise files

Learn by watching, listening, and doing! Exercise files are the same files the author uses in the course, so you can download them and follow along. Exercise files are available with all Premium memberships. Learn more

Get started

Already a Premium member?

Exercise files video

How to use exercise files.

Ask a question

Thanks for contacting us.
You’ll hear from our Customer Service team within 24 hours.

Please enter the text shown below:

The classic layout automatically defaults to the latest Flash Player.

To choose a different player, hold the cursor over your name at the top right of any lynda.com page and choose Site preferences from the dropdown menu.

Continue to classic layout Stay on new layout
Exercise files

Access exercise files from a button right under the course name.

Mark videos as unwatched

Remove icons showing you already watched videos if you want to start over.

Control your viewing experience

Make the video wide, narrow, full-screen, or pop the player out of the page into its own window.

Interactive transcripts

Click on text in the transcript to jump to that spot in the video. As the video plays, the relevant spot in the transcript will be highlighted.

Are you sure you want to delete this note?

No

Your file was successfully uploaded.

Thanks for signing up.

We’ll send you a confirmation email shortly.


Sign up and receive emails about lynda.com and our online training library:

Here’s our privacy policy with more details about how we handle your information.

Keep up with news, tips, and latest courses with emails from lynda.com.

Sign up and receive emails about lynda.com and our online training library:

Here’s our privacy policy with more details about how we handle your information.

   
submit Lightbox submit clicked
Terms and conditions of use

We've updated our terms and conditions (now called terms of service).Go
Review and accept our updated terms of service.