June 2012
Intermediate to advanced
226 pages
5h 5m
English
Content preview from Web Performance Daybook Volume 2Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Chapter 4. The Art and Craft of the Async Snippet
JavaScript downloads block the loading of other page components. That’s why it’s important (make that critical) to load script files in a nonblocking asynchronous fashion. If this is new to you, you can start with this post on the Yahoo User Interface (YUI) library blog (http://www.yuiblog.com/blog/2008/07/22/non-blocking-scripts/) or the Performance Calendar article (http://calendar.perfplanet.com/2010/the-truth-about-non-blocking-javascript/).
In this post, I’ll examine the topic from the perspective of a third party—when you’re the third party, providing a snippet for other developers to include on their pages. Be it an ad, a plug-in, widget, visits counter, analytics, or anything else.
Let’s see in much detail how this issue is addressed in Facebook’s JavaScript SDK.
The Facebook Plug-ins JS SDK
The Facebook JavaScript SDK is a multipurpose piece of code that lets you integrate Facebook services, make API calls, and load social plug-ins such as the Like button (https://developers.facebook.com/docs/reference/plugins/like/).
The task of the SDK when it comes to Like button and other social
plug-ins is to parse the page’s HTML code looking for elements (such as
<fb:like> or <div class="fb-like">) to replace with a
plug-in. The plug-in itself is an iframe that points to something like
facebook.com/plugins/like.php with the
appropriate URL parameters and appropriately sized.
This is an example of one such plug-in URL:
https://www.facebook.com/plugins/like.php?href=bookofspeed.com&layout=box_count ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.