This page, WebDev_MsgRcvr.html, is loaded into an iframe in WebDev_MsgSndr.html. The two pages send
messages back and forth to demonstrate how JavaScript messaging works.
1.1 'sections' Message
This page reponds to a message "sections" by toggeling display of a bottom menu page listing all the
sections in this page. Click the "Send Message 'sections'" button to see that happen.
1.2 'request' Message
It also responds to a message "request" by sending back its url in a reply message. If you click
that button you will see the display change from "No Reply" to "Received Reply"
2.0 Actions
The actions, cited above, are implemented this way:
When a "sections" message arrives, the onmessage(event) handler
invokes JavaScript method bottomMenu.sections() which toggles the display
of page-sections markup.
When a "request" message arrives, it posts back its url to the WebDev_MsgSndr sender.
That's all this page does to support this demonstration. All the code for this is shown in
the code blocks below this iframe.
bottomactionsrequestsectionsdemotop