Recent Posts

Topic: Agile Web Development with Rails, 3rd Edition / C2 8.3 problem with nomethoderror

Fixed my issue. While going over my code this morning after I woke up, I noticed my ifelse statement was wrong in cart.rb. For some reason it didn’t save the changes I made when adding

@items << CartItem.new(product)

Everything else was saved…don’t know why that wasn’t. It’s wondrous what a good nights sleep can do to tired eyes staring at code all day long.

Topic: Hello, Android / onDraw not drawing the bitmap right away

Glad to help.

Topic: Agile Web Development with Rails, 3rd Edition / Session - "Data too long" using MySQL

I edited http://www.pragprog.com/wikis/wiki/ChangesInRails23 to reflect this.

Topic: Agile Web Development with Rails, 3rd Edition / C2 8.3 problem with nomethoderror

So, I have that lovely NoMethodError listed in 8.3 (pg105 in book)...the problem is it’s not resolved by the books instructions (they’re the same as the pdf).

restarting server doesn’t fix it, hosing cookies doesn’t fix it, clearing the sessions db doesn’t fix it. I’m at a loss for what the problem is. My code is the same as the demo code (I’ve gone through line by line and even c&p’d).

ruby 1.8.7p72
rails 2.3.2
mysql 5.1.3

error:

NoMethodError in Store#add_to_cart 
Showing app/views/store/add_to_cart.html.erb where line #4 raised: 

undefined method `quantity' for #<Product:0x4cfe410>

Extracted source (around line #4): 

1: <h2>Your Pragmatic Cart</h2>
2: <ul>
3:   <% for item in @cart.items %>
4:     <li><%= item.quantity %> &times; <%=h item.title %></li>
5:   <% end %>
6: </ul>

Topic: Hello, Android / onDraw not drawing the bitmap right away

Thanks Ed for the help via email. You help me solved the issue.

Topic: Writing Your First iPhone Application / Unload Nib files

Hi,

I’m loading a NIB via IB in my project (iphone project) which uses a UITabBarController.

I need to unload NIBs as the user navigates to a new UITabBarItem since these aren’t being unloaded automatically. I’m concerned about memory usage and would like to reload the NIB (hopefully automatically) when the user presses the tab bar item.

Regards,

Shoaib Raza

Topic: Language Design Patterns / ANTLR and the language machine

Hi Glenn,

From my initial scan, it looks like an idea the author had in the 1970s. It appears to be a pattern matcher that does rewrites. I don’t think it does anything as sophisticated as MetaEnvironment or Stratego. I’m working with Leon Su on ANTLRMorph, a very similar system.

Ter

Topic: Practical Programming / Python 2.5?

Hi Bill,

I went through the same frustrating process. I finally did uninstall and start with Python 2.5 and so far every thing is working okay.

Supposedly one of the authors is going to post an update to the software installation instructions that fixes the current problems but that hasn’t happened yet.

Dave

Topic: PragPub / July 2009

I’m reading the Kindle edition and it would be nicer if the Table of Contents worked. Otherwise I am liking the magazine so far.

Topic: Using the Map Kit / Welcome!

Hi Agustin,

There is no way (that I know of) to have map kit do the moving of the pin, you have to write that yourself. Once the pin drops its relatively easy to convert view locations to geoloc’s.

Good luck!

Topic: Developing Facebook Platform Applications with Rails / Redirected to API feed after login

You can use request.request_uri

Topic: iPhone Development / iPhone OS 3.1

We’re going to ship the book—there will always be something new coming along.

Hear, hear!

Someone else is planning to release a new edition of their book (updated for 3.0) in July. I’d like to see the PragProg book make it out the door first (which could still happen, if the other book’s schedule slips).

Topic: iPhone Development / Marquee

Hello, I am trying to create a banner display that scrolls large letter text across the iPhone screen like a marquee or billboard. Does anybody have any code or pointers as to how to do this? Any information is appreciated.

Thanks
duncwa

Topic: Using the Map Kit / Welcome!

Hi Bill,

I am building a very cool app where the users can find restaurants, bars and coffee shops. Yesterday I took your MapQuakes tutorial, and by today I already have near by places shown on the map each with a different color. Great tutorial.

Does the MapKit Framework provides a method to drop a pin, drag it into the map and then obtain the coordinates for that specific place?

Hope to hear from you.

Topic: I'd Like a Book That Covers… / A book about C#

Absolutely there are dozens of books on the C# topic. I think what might be missing is a ‘best practices’ approach to the topic. That’s what pragprog is good at.

Is that enough for a book? I don’t know. Maybe a column in the new monthly.

Topic: PragPub / Subscribe

This is also the info I was looking for.

Topic: Coding in Objective-C 2.0 / When other episodes?

Hi!
When will You upload new episodes (like unit testing) ?
Thanks.

Alvise Susmel

Topic: PragPub / July 2009

I had previously run across references to Clojure, but it never really caught my attention (not even pragdave tweeting about getting it to work with SLIME). The demonstration of the condition system convinced me that it could actually be a “real Lisp” and piqued my interest.

Topic: Rails for Java Developers / Page 26 question...

Got past this issue by using “form_tag”. In page 28, there is reference to paginate, but “classic_paginate” has been removed from rails 2.x. Also the link to the plugin doesnt work. So the only way is to use a third-party paginate ( will_paginate ) which given where i am in the book, have no idea to use it.

THIS BOOK NEEDS TO BE UPDATED…ANYBODY ?

Thanks

pady

Topic: Core Animation / Cannot control order of layered subviews being displayed

Hi Genu,

I would not be using subviews but instead add sublayers to your root layer.

The layer hierarchy works more or less the same way the view hierarchy does but if you are changing the layer that belongs to a view you can get into trouble.

Hope this helps.

Topic: I'd Like a Book That Covers… / Writing

More specifically, expositional prose (as opposed to – say – API reference doco).

I think this important in software development – analyzing complex situations and communicating our understanding. It is a skill that many of us have little natural aptitude for, but that we don’t commonly get a great much on. Even in companies with document-heavy processes, the typical starting point will be a template document with blank sections that somehow have to be filled. Moreover, there are plenty of forms of communication (problem analyses entered in to bug-tracking systems, pages in internal wikis, email) which benefit from being well composed, but that are essentially free-form.

As to who I’d like to see authoring such a book, I’m not really sure. I was going to suggest Richard P. Gabriel – but I don’t think that would be quite right. Gabriel’s “Writing Broadside” was to do with writing conference papers, and a conference paper is some that will have a long gestation period, going through a number of revisions. But what we often need to do it to be able to write things well, quickly. Perhaps journalism is a better model than essaying.

Topic: Core Animation / Cannot control order of layered subviews being displayed

Hi,

I am new to working with Core Animation and I was hoping somebody could help me.

I am trying to display two subviews (with layers) on a view in a particular order but I am unable to do it in the correct order.

One of the subviews (A) contains a single layer of polygons (drawn using NSBezierPath) while the other subview (B) has multiple layers each containing an image. I want to display subview A on top of subview B but the subview B always get displayed on top.

I have tried changing the order of adding the subviews to the main view but the result is always the same.

I have tried this before successfully on subviews without any layers. Any help is appreciated.

Thanks
Genu

Topic: Pragmatic Thinking and Learning: Refactor Your Wetware / Mind Maps

Yup, I rummaged one Buzan’s books out of the library. Its puffed out a bit, but it does offer ideas of how to use the mind maps in different arenas besides note taking.

Topic: Domain-Driven Design using Naked Objects / Are the "DDD in context" sidebars useful?

Hi all,
One bit of feedback I’ve had from one my of technical reviewers is the usefulness – or not – of the “DDD in context” sidebars. My reason for including them was that, because this book is very hands-on, to provide signposts for the interested reader who wants some further theory (most probably to Evans’ original DDD book).

Does anyone working their way through the book think these sidebars are useful? Or, are they too short to provide any value and just get in the way?

Your opinions welcome!
Thanks
Dan

Topic: Developing Facebook Platform Applications with Rails / Redirected to API feed after login

I haven’t tried this yet, because I don’t know how to figure out what the original URL was. For example, in my case the user is trying to go to:

apps.facebook.com/magicwish/canvas/bookmark_add?itemurl=<a href="http://www.bestbuy.com/site/olspage.jsp?skuId=8996571&amp;st=8996571&amp;lp=1&amp;type=product&amp;cp=1&amp;id=1218008111594">www.bestbuy.com/site/olspage.jsp?skuId=8996571&amp;st=8996571&amp;lp=1&amp;type=product&amp;cp=1&amp;id=1218008111594</a>

But they end up at:

<myserver.com>:3000/?auth_token=7d32e62c7ad16e0...

How can I determine the original URL in the after_facebook_login_url method?