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mFabrik Blog is about mobile and web software development, open source and Linux. We tell exciting tales where business, technology, web and mobile convergence.

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Native mobile application development with Plone, WordPress and Python

Posted on February 9, 2011

We have just released two mobile applications backed by Plone, WordPress and Python middleware code. In this blog post I’ll tell some background information what we have learnt with mobile applicationand Python development.

mFabrik News – download now for iPhone and Android

Why create a mobile application?

The first question is why one rather create a mobile application when the same task can be accomplished with a mobile site? Most people even prefer mobile sites over applications. From a pure engineering viewpoint, mobile applications are usually just glorified RSS readers that embed Webkit and add some native user interface bling bling over it. With an app, you are limiting your target audience, because an application is limited to one platform. Maintaining application(s) and application developers is more expensive compared to a mobile site which few (cheap) PHP junkies can throw together.

But is not always technology or price which matters. Mobile applications have prestige value – having or showing success, rank, wealth, etc. If you have a high quality brand, you probably want to have a mobile application too. When you see the brand logo swinging forth and back in an iPhone application with smooth animation running 60 frames per second, you see that it is a proper placement for the brand logo. The output is more luxury, more carefully planned, and does not look like it was thrown together by few cheap web developers.

There are even rationale reason for going after applications. First, you are in a business of making money. It is a lot of easier when the platform itself is offering you a payment solution without a monthly fees (iTunes payment). Other good reason is that there exists interaction between the application and your content beyond the browser window.  You can push messages or do things even if the user is not on your site (see more information about the push solution we implemented below).

Mobile application development and Python

As most of this post readers are probably fellow Python developers, here are some thoughts specifically aimed for them. Python itself is not a very good alternative what comes to mobile application development. Though, the application itself may not contain Python code, Python still shines on the backend side of the things. For example, we’ll hope to publish an example application using Google App Engine in the near future.

The only future proof platform where Python is 1st class citizen for building applications, is Nokia’s Meego with its Pyside and Qt bindings. Unfortunately Meego doesn’t have any shipped handsets and looks like it never will.

Android has script bindings, but they are not good enough for real application development, as interaction with the native platform happens over TCP/IP sockets. However, Android has seen some recent exciting development from PyPy project, possibly enabling native Android development for Python in the future.

iOS with Python could be a go, now when Apple has lift ban on interpreted languages. I haven’t heard anybody doing it yet, though. CTypes had some problems long time ago regarding run-time generated code for Python bindings.

Python has also a port for Series 60 (Symbian) – don’t go there if you are not prototyping. It is good platform for students for  playing around, but unfortunately it has never been considered as serious development environment by the handset manufacturer. You have tons of headaches if you actually want to release a product version of your application.  Nokia N900, soon supported. is better prototyping platform for Python than Series 60 as you get full Debian userland.

Mobile application development and wrappers

There exist various wrapper technologies which help you to wrap your HTML5 application to a native application shell. With simplistic APIs provided through Javascript bindings, you can access a limited subset of native platform APIs. Wrapper technologies are mostly aimed for web developers, who do not have any experience on application development and they might want to skip the learn experience of native development.

Wrapper technologies do their job and produce decent apps. But if you are a Python developer I recommend you skip the wrapper step and build your own native user interface and embed Webkit yourself. Designing an user interface is much is easier with Apple’s Interface Builder or Google’s  Android tools than with half-baked Javascript bindings. The fact that you are actually able to insert a real breakpoint into your code is itself worth of skipping wrappers. If you already are a Python developer you already know at least one real programming language and mastering Objective-C or Java should be an easy task for you.

Webkit itself has bugs. You will regularly hit obscrure bugs when the amount of  Javascript and CSS code grows. In the worst cases Webkit just dies under your application without a way to debug the problem – sometimes without a workaround available for the problem. This means dead end for your lovely application. You don’t want to end up to this situation. So, just to have more low level control, using native tools is good.

mFabrik News application

mFabrik News mobile application allows you to follow the latest news of mobile and web development, produced by our hacking team. The applications source the news from our Plone based web site and WordPress blog (which you are currently reading). It uses special RSS streams prepared with our Web and Mobile multichannel publishing solution: news images are optimized for mobile device screens using a handset database (Wurfl) and some other HTML preproessing is done to make the posts look better in embedded WebKit. Processing is done using mobile.sniffer and mobile.htmlprocessing Python packages which are generic Python packages and should be usable in various environments, including App Engine.

iOS mFabrik News application has push notification support. Android doesn’t yet implement push solution, but it is coming for Android 2.2 handsets.  Please see the earlier blog post how we use Apple Push Notifications with Python.

Download, give the apps a spin and report any feedback! (direct links at the beginning of the post)

We may or may not release the source code of the applications, depending if anybody thinks they actually would find it useful.

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Finding an application download link for App Store or Android Market

Posted on January 28, 2011

For App Store, search your application in itunes.apple.com and copy-paste View in iTunes link.

For Android, search for your application in Android Pit and copy-paste Android Market Link. Android Pit also provides QR code (2D barcode) for your application.

Note that URL shorteners (bit.ly) do not like market:// protocol, so you might need to use alternative http://market.android.com notation. This, however, prompts a dialog in the device “Would you like to open this URL in a browser or in Market Place?”

More info

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Python 2.3, Python for Series 60 1.4.5 still in use… and insight into Symbian deployment process and user experience

Posted on August 18, 2010

Nokia’s Python for Series 60 has a long history. It is a Python interpreter, originally escaped from Nokia prototype labs, running in your phone. It is said to been awesome to show mobile/embedded developers, who were love with their static C compilers and 4 hours built times, opening a Python prompt in your phone and typing import audio; audio.say(“your phone loves Python”) by keypad (Nokia Series 60 phones come with a speech synthetizer). Python for Series 60 is the best tool of building a simple proof of concept mobile applications. The lack of speed, lack of good UI libraries and difficult deployment problems makes it challenging to use it in production grade environments.

PyS60 has also a history of staying in archaid Python version – namely Python 2.3. It was not until this February when stable PyS60 2.0.0 with Python 2.5 was released (1.9.x was considered experimental according to the release notes). Luckily looks like new winds are blowing (Qt acquisition, Meego/Maemo) and Python is getting higher priority. For example, PySide Qt bindings is very high profile project. Based on this, we hope to expect Python to the first class citizen in the future Meego and Symbian devices.

My company had a little side venture with PyS60 Community Edition when we were still betting that Symbian and Python would rock the world – the era before iPhone changed the game.  PyS60 community edition was effectively a revamped PyS60 1.4.x with Python 2.3 toolchain which actually made PyS60 application production deployment possible. Possible…? -you ask. Madness… no. It is Symbian. It is certification and signing and obscure error messages. Basically vanilla PyS60 is being shipped as an external SIS (Symbian package format) and Symbian platform security makes it impossible to deploy two production signed applications using vanilla PyS60 on the same device. The only cure was statically building Python for both apps from the scratch, which is exactly what PyS60 Community Edition was doing.

But this all was long long time ago. Aeons in mobile time. So I was today surprised when I got email from a person (David) using PyS60 Community Edition. We never upgraded PyS60 Community Edition to Python 2.5 . In fact we haven’t touched the project about two years. David was effectively using Python 2.3 and asked questions about the tool chain internals.

My first answer was a question Why on Earth you are still using Python 2.3? I thought maybe the guy had somehow missed the last two years or was a stuck with an old phone.

However… this was not the case and the answer was very insigtful.

Yes, I’m aware of PyS60 2.0.0, but I prefer PythonCommunity, at least for the moment: no OpenC neither Platform Services dependencies; smaller .SIS size and memory footprint. I think that the final .SIS produced with PythonCommunity, with everything necessary to run contained in it and with a clean installation without multiple dependencies, is a better fit for a mass-market than the files produced by PyS60 2.0.0, above all taking into account that people don’t know what S60 or Symbian are.

Also, the runtime deployment on the new PyS60 isn’t automatic for S60_3rd and S60_FP1 devices, so in the worst case scenario, users may end having to learn to install the different files (pips.sis, ssl.sis, stdioserver.sis, Python_2.0.0.sis, PythonScriptShell_2.0.0.sis) in the correct order, which is a big no-no for a mass-market deployment.

So…. I hope someone in Nokia is reading this blog entry carefully. Do it like Apple does. Make your application deployment static. Make OpenC static. Make every freaking library which is not shipped with the device statically buildable. It should be possible now when everything is open source. It will consume precious device RAM, but at least it will make mass market application development possible. SIS hell is worse hell than deb hell, or DLL hell, as the end user cannot fix it due to device security.

In the related news SIS smart installer was announced few weeks ago. Personally I wouldn’t bet it can deal with all the problems of versioning and Symbian platform security. Forum reports aren’t promising and looks like very Symbianish user experience can be expected. In positive light, it seems that Python is being considered for this process.

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CodeSign error: a valid provisioning profile is required problem in XCode

Posted on August 17, 2010

The above error pop-ups when you try to build iPhone application for the device. It means that the provision name in XCode project settings does not match .provision file installed in XCode Organizer (device manager). Usually this happens when you have downloaded XCode project created by someone else.

It should be possible just to go to XCode -> Project -> Project settings and chose a valid code signing profile (Code signing -> Code signing identity drop down should have been populated from the choices available in XCode organizer). However, it seems that there is a bug and always changing this setting does not have effect. Based on reports, it looks XCode project setting updater is confused about something and does not update the setting correctly.

The hardcode workaround is to edit your XCode project .xcodeproj file manually. You do not need to close down XCode for this (it will automatically ask to reload after the file is saved). You may see duplicate entries of  XCBuildConfiguration. You need to hunt down one with old (incorrect) values and manually copy-paste in correct values. You can get the correct values from XCode organizer.

For example, I had to edit in :

	CODE_SIGN_IDENTITY = "iPhone Developer: Mikko Ohtamaa (XXXYYY)";
	"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "iPhone Developer: Mikko Ohtamaa (XXXXYYY)";
...
                PROVISIONING_PROFILE = "7572BAC6-4F0C-46D3-B96F-XXXXXYYY";
	"PROVISIONING_PROFILE[sdk=iphoneos*]" = "7572BAC6-4F0C-46D3-B96F-XXXXXYYYY";

manually to the file, replacing the old values for these settings. Note that values may be in many lines.

Hope this helps someone.

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