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2015 Nov 19, 8:36
The @USNatArchives just announced it is displaying The Refugee Act in its rotunda today. https://www.flickr.com/photos/usnationalarchives/sets/72157661462319371 … pic.twitter.com/GxKALnV4xV
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Considerate MessagePort Usage

2013 Aug 7, 7:14
Sharing by leezie5. Two squirrels sharing food hanging from a bird feeder. Used under Creative Commons license Attribution-NonCommercial-NoDerivs 2.0 Generic.When writing a JavaScript library that uses postMessage and the message event, I must be considerate of other JS code that will be running along side my library. I shouldn't assume I'm the only sender and receiver on a caller provided MessagePort object. This means obviously I should use addEventListener("message" rather than the onmessage property (see related What if two programs did this?). But considering the actual messages traveling over the message channel I have the issue of accidentally processing another libraries messages and having another library accidentally process my own message. I have a few options for playing nice in this regard:
Require a caller provided unique MessagePort
This solves the problem but puts a lot of work on the caller who may not notice nor follow this requirement.
Uniquely mark my messages
To ensure I'm acting upon my own messages and not messages that happen to have similar properties as my own, I place a 'type' property on my postMessage data with a value of a URN unique to me and my JS library. Usually because its easy I use a UUID URN. There's no way someone will coincidentally produce this same URN. With this I can be sure I'm not processing someone else's messages. Of course there's no way to modify my postMessage data to prevent another library from accidentally processing my messages as their own. I can only hope they take similar steps as this and see that my messages are not their own.
Use caller provided MessagePort only to upgrade to new unique MessagePort
I can also make my own unique MessagePort for which only my library will have the end points. This does still require the caller to provide an initial message channel over which I can communicate my new unique MessagePort which means I still have the problems above. However it clearly reduces the surface area of the problem since I only need once message to communicate the new MessagePort.
The best solution is likely all of the above.
Photo is Sharing by leezie5. Two squirrels sharing food hanging from a bird feeder. Used under Creative Commons license Attribution-NonCommercial-NoDerivs 2.0 Generic.
PermalinkCommentsDOM html javascript messagechannel postMessage programming technical

2012 Oct 22, 11:24

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2012 Oct 22, 11:24

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A New Species Discovered ... On Flickr (npr.org)

2012 Aug 11, 9:17

Winterton, a senior entomologist at the California Department of Food and Agriculture, has seen a lot of bugs. But he hadn’t seen this species before.

There’s no off switch when you’re the senior entomologist. If you’re browsing the web you find your way to Flickr photos of insects or start correcting Wikipedia articles on insects.

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Code: Flickr Developer Blog » Parsing Exif client-side using JavaScript

2012 Jun 1, 2:51

Flickr parses the exif out of images using Web Workers, and Blob (File API)!

PermalinkCommentsjavascript blob exif image technical programming dom webworker web-browser

Raising the bar on web uploads

2012 Apr 25, 5:00

Flickr’s new HTML5-ish photo upload feature technical overview.

PermalinkCommentstechnical html html5 javascript css3 css flickr file-upload

Fwd: Alex Water Lessons

2012 Mar 10, 9:42

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Fwd: Alex Water Lessons

2012 Mar 10, 9:42

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Fwd: High chair

2012 Feb 13, 12:58

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Fwd: High chair

2012 Feb 13, 12:58

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Alex and glo friend

2012 Jan 17, 4:52

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Alex and glo friend

2012 Jan 17, 4:52

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Musée McCord Museum’s photostream on Flickr.

2012 Jan 15, 10:37


Foot race, Dawson City, YT, about 1900Cricket match, McGill campus, Montreal, QC, about 1890Football game on campus, McGill University, Montreal, QC, about 1900S. S. "Nascopie" at sealing grounds, 1927

Musée McCord Museum’s photostream on Flickr.

PermalinkCommentsphoto old-timey black-and-white history

Alex on quilt

2012 Jan 14, 9:41

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Alex on quilt

2012 Jan 14, 9:41

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Alex asleep in baby chair

2012 Jan 14, 3:17

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Alex asleep in baby chair

2012 Jan 14, 3:17

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Alex in standing thing

2012 Jan 4, 9:30

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Alex in standing thing

2012 Jan 4, 9:30

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