It started with this Code Craft blog post on the Code Garden – an analogy that sucked less. It got me thinking and ranting about metaphors in software and metaphors of software. Designing your technical architecture with software, the XP “Metaphor” practice, metaphors for HCI, metaphors like those used in the Head First series and Ajax Patterns to explain concepts, metaphors to explain what software is to managers. Where do they make sense and where is it plain wrong to try and explain software with a metaphor.

22 minutes.

• Where did patterns come from? Not GoF, not Alexander.
• Alexander, patterns, and architecture.
• Patterns in the organisation – how can a pattern language pervade an organisation and help workers carry out its mission statement and operating principles? Different high level patterns (e.g. “People first” for one company, “Technology first” for another) mean different lower-level patterns (crude example: staff pattern in people-oriented firm – “managers come from HR” versus staff pattern in tech-oriented firm – “Managers become tech leadership”)
• Wikis were literally built for patterns
• Promoting and deploying patterns

This podcast covers eight patterns on debugging/diagnosis of Ajax Apps, as well as testing Ajax apps, and I’m joined by Craig Shoemaker from Polymorphic Podcast, also a co-author of “Beginning Ajax with ASP.NET”. After some announcements, the interview begans at 6:00. The podcast overall is 60 minutes.

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p> Ajax Diagnosis Patterns:

• Logging
• Debugging
• DOM Inspection
• Traffic Sniffing

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p> Ajax Testing Patterns:

• Simulation Service
• Browser-Side Test
• Service Test
• System Test

With the series now complete, the podcast will now resume regular Sotware As She’s Developed topics including but not limited to agile development, Ajax, the web, and usability. Also, more conversations – please drop me a line at michael@mahemoff.com if you’d like to come drop in for a skype chat.

As always, credits on this podcast to My Morning Jacket for the lead-in track, “One Big Holiday”. All podcasts in this series licensed under CC.

Audio Note: Sorry about the noise at some stages in this recording – I now know a lot more about audio levelling (the problem of keeping both ends at the same level), but at the time this was recording, it turned out I had set Craig’s end at too low a volume. I used Levelator to level each end, leading to too much noise…next time I’ll need to pump up the volume at each end from the start. I’m also looking forward to resuming use of Bias SoundSoap, but there’s no easy way to get this running on an Intel Mac for now!

• Lazy Registration
• Direct Login
• Host-Proof Hosting
• Timeout
• Heartbeat
• Unique URLs
• Dynamic Favicons

Dedicated to the Nitobians, whose last podcast inspired me to crank another one out again. Recent events suggest it may cost me $5000 to appear on their podcast again, and as Andre points out in this podcast, the same applies for them appearing on my podcast. Thus, my simple proposal would be:

1. Each of us appear on the others’ podcast, at $5000 each. Actually, let’s make that $50k each.
2. Cancel the debt
3. Now each of us can claim our podcast attracts guests who pay $50k to appear. Enough to cover headsets ($20), bandwidth ($10/month with Libsyn), and assorted beverages (name your price).
4. …
5. Profit!!!

Soon I’ll be publishing the final podcast in the overall series, which has already been recorded, and then I’ll be taking it in a more general direction akin to the topics on this blog – talking about agile, programming (Java/Rails/etc), usability, Web2.0, as well as Ajax and the coming revolution of real-time webapps. If you have a skype account and you’d like to join me sometime, drop us an email (michael@mahemoff.com). Also feel free to suggest any topics that would be good to cover.

This 13-minute podcast covers ten patterns of Ajax Architecture (Book: Chapter 16, pp 445-472):

• One-Second Spotlight
• One-Second Mutation
• One-Second Motion
• Highlight

The guest for this week is Dave Johnson of Nitobi (the Ajax component developers formerly known as E-Business Applications), widget guru and author of the upcoming Enterprise Ajax book. Dave helps me walk through the patterns and offers plenty of great insights along the way. We mention Dave’s recent presentation a couple of times; here’s the PDF.

This 54-minute podcast covers ten patterns of Ajax Architecture (Book: Chapter 15, pp 389-444):

• Drag-And-Drop
• Sprite
• Popup
• Malleable Content
• Microlink
• Portlet
• Status Area
• Update Control
• Virtual Workspace

I’m asking guests to join me for most of the remaining Ajax Pattern podcasts. Seeing patterns from someone else’s perspsective will make the discussion richer and hopefully cover more questions you might have as you’re listening to the podcast. The guest for this week is Andre Charland of E-Business Applications, widget guru and author of the upcoming Enterprise Ajax book.

This 83-minute podcast covers nine patterns of Ajax widgets:

• Slider
• Progress Indicator
• Drilldown
• Data Grid
• Rich Text Editor
• Suggestion
• Live Search
• Live Command-Line
• Live Form

• Browser-Side Cache Maintain a local cache of information.
• Guesstimate Instead of grabbing real data from the server, make a guesstimate that’s good enough for most user’s needs. ITunes Download Counter, GMail Storage Counter.
• Multi-Stage Download Quickly download the page structure with a standard request, then populate it with further requests.
• Predictive Fetch Anticipate likely user actions and pre-load the required data.
• Fat Client Create a rich, browser-based, client by peforming remote calls only when there is no way to achieve the same effect in the browser.
• Pseudo-Threading Use a timer and a worker queue to process jobs without the blocking application flow.
• Code Compression Compress code on the server, preferably not on the fly.

(Note that the last two are recent additions to the wiki and just stubs at this stage.)

Okay, here endeth the series. I will soon be starting up a new series on the next group of patterns (Part 5 in the book): Functionality and Usability Patterns. There will be a change in the format, one I hope you’ll enjoy!

• XML Data Island Retain XML responses as “XML Data Islands”, nodes within the HTML DOM.
• Browser-Side XSLT Apply XSLT to convert XML Messages into XHTML.
• Browser-Side Templating Produce browser-side templates and call on a suitable browser-side framework to render them as HTML.

The second group of patterns (representing a different chapter in the Ajax Design Patterns book) are a couple of generic Javascript patterns to make the code more maintainable and portable:

• Server-Side Code Generation Automatically generate HTML and Javascript from server-side code.
• Cross-Browser Component Create cross-browser components, allowing programmers to reuse them without regard for browser compatibility.

The 40-minute podcast covers the following patterns:

• Call Tracking Accommodate busy user behaviour by allocating a new XMLHttpRequest object for each request. See Richard Schwartz’s blog entry.Note: Pending some rewrite to take into account request-locking etc.
• Periodic Refresh The browser refreshs volatile information by periodically polling the server.
• Submission Throttling Instead of submitting upon each Javascript event, retain the data in a local buffer and upload it periodically.
• Explicit Submission Instead of submitting upon each Javascript event, require the user to explicitly request it, e.g. submit upon clicking a button.
• Distributed Events Keep objects synchronised with an event mechanism.
• Cross-Domain Proxy Allow the browser to communicate with other domains by server-based mediation.

This podcast covers six patterns on Browser-Server Dialogue: Call Tracking, Periodic Refresh, Submission Throttling, Explicit Submission, Distributed Events,

Thanks for your feedback since last time. Good, bad, or ugly, it’s all welcome – in the comments for this podcast or michael@mahemoff.com.