tekin.co.uk - Ruby on Rails developer, Tekin Suleyman, Manchester UK

The MagRails Attendee's Guide To Manchester

2011-10-04T00:00:00+01:00

Attending the MagRails Conference here in Manchester next week? Never been to the city and in need of some pointers? Well you’ve come to the right place! Here follows my whistle-stop tour of our fair city, aimed at helping you get the most out of your stay in Manchester. I’m not going to pretend this is a comprehensive guide; in fact it’s anything but. It’s essentially the list of places I’d recommend to a visiting friend. I’ve focused mainly on Manchester’s Northern Quarter as this is where the conference is taking place and I’ve also tried to avoid chains as much as possible – if you really want to find the nearest Starbucks or McDonalds, then you won’t struggle.

The NWRUG Drink Up, Sponsored by Engine Yard

If you arrive the night before the conference, then be sure to head straight over to NoHo bar where the North West Ruby User Group (NWRUG) are holding a social drink-up, generously sponsored by Engine Yard. Things kick off from 7:30pm, more details on the NWRUG website.

The Best Place for a Coffee

If you’re after a proper coffee in Manchester city centre, then there is only one place to go: North Tea Power. Whether it’s a flat white, espresso or single origin V60 pour-over you’re after, the guys and girls at NTP will always deliver the goods. It’s also laptop-friendly, has free WiFi and is just a short walk from the conference venue.

TeaCup on Thomas St also does an excellent coffee and has a great range of teas and homemade cakes and also does mean poached eggs for breakfast. Other places to visit include the wonderfully quirky Oklahoma, Suger Junction for something sweet, and Koffee Pot for their amazing cooked breakfasts.

Where to Eat

There are plenty of great places to grab a bite around the city, and you’re especially lucky during the week of the conference as the Manchester Food and Drink Festival is on – be sure to check the programme for some culinary treats.

If you’re after a a quick, simple lunch during the day, you have quite a few options. The falafel and haloumi kebab at Common in the Northern Quarter is a personal favourite, as is the Walrus bento box. For some tasty Korean food, head to Baekdu on Shudehill. If you’re after choice, then you could do worse than visit the Arndale Market Food Hall – plenty of options here for food from around the world, but special mention has to go out to Pancho’s Burritos; just don’t forget the habanero sauce! Vegetarians and Vegans should check out Earth Cafe.

There are also a couple of lunch options around Piccadilly Gardens, such as Bar Burrito, Rice and Kro.

However, if lunch like a proper Mancunian is what you’re after, then a visit to one of the Northern Quarter’s famous back-street curry cafés is a must. Be prepared for some very basic surroundings with canteen-style service, but quite possibly the tastiest curry for under a fiver you will ever have! Popular places include This & That, Yadgar and Al Faisal, although my personal favourite (and possibly the most insalubrious) is definitely Café Marhaba, if only because they make the best naan breads and rotis, straight out of a tandoor oven.

For something a little more upmarket or for dining in the evening, head to: The Market Restaurant for the traditional British restaurant experience; East Z East for a fantastic curry; Chaophraya for great Thai food; The Mark Addy or Sam’s Chop House for top quality English pub grub; San Carlo or Cicchetti for Italian food; Dough for pizza; Baekdu for Korean; Tokyo Season for Japanese; Red Chilli for spicy Sichuan Chinese food; and Little Yan Sing for more traditional Chinese cuisine.

Ale Drinkers Rejoice!

If you like your beer, then you are in for a treat! First on your list of places to visit should be The Port Street Beer House. Serving a vast selection of craft beers from around the world, you cannot fail to find something exciting to quench your beer-thirst.

Not far from Port Street is Bar Fringe. A real Mancunian institution with more of a focus on continental beers from across Europe, they also have a good range of local British ales. You can expect fewer Hipsters than Port Street, plus your money will definitely go further.

You’d also do well to visit Manchester’s very own microbrewery, located in the Grade II listed Marble Arch pub on Rochdale Road. Situated in Ancoats – the heart Manchester’s industrial revolution – this is where the Marble Brewery produce their casks ales, all of which are strictly organic and vegan. They’ve also recently opened up a bar on Thomas Street if you want to sample a Marble beer without the walk into Ancoats. Try the Chocolate Marble.

Other bars worth of a mention include: Common (run by the same lot who run Port St), Soup Kitchen; and The Castle Hotel. Oh, and if drinking in an ex-public toilet sounds appealing, then head to The Temple of Convenience.

The cocktail drinkers amongst you should head to either Keko Moku or Apotheca, both within spitting distance of each other. Cloud 23 might also tickle your fancy, if only for the views over Manchester from the 23nd floor. Wine buffs should head for Hangingditch.

Music Fans

The music fans amongst you will want to check out both Vinyl Exchange and Piccadilly Records – both top-quality independent record shops. There’s also a thriving music scene in Manchester, with plenty of clubs and gig venues across the city, catering for all tastes. Venues to check out for some live music or clubbing: Islington Mill, Band on the Wall, The Deaf Institute, The Ruby Lounge, Night & Day Café, Matt & Phreds Jazz club (which also does a pretty good pizza), Soup Kitchen or Mint Lounge. The guys at Now Wave put on several gigs a week at various venues, featuring both up and coming bands and more established acts. Finally, it would be remiss of me not to mention the clubbing behemoth that is The Warehouse Project.

Culture Vultures

October is a great time to be visiting Manchester if you’re into the arts. The weekend of the conference is particularly well served as the good people over at the Creative Tourist website have curated a whole weekend’s worth of cultural events to keep you entertained: The Manchester Weekender. And if you’re into independent cinema, be sure to pay The Cornerhouse a visit.

Nearest Apple Store

Knowing the location of your nearest Apple store is very important, especially if the rumours are to be believed and the soon-to-be-announced iPhone 5 is released on the day of the conference…

MadLab – The Manchester Digital Laboratory

Manchester’s very own community hack space, this is where many of the local user groups and tech meet-ups happen. Check the MadLab website for more details.

Don’t forget your brolly!

Manchester isn’t known as the Rainy City for nothing!

If you find this useful, want any more pointers or spot anything I’ve missed, feel free to drop me a line on Twitter.

Default Attributes on Active Record Associations in Rails

2011-08-26T00:00:00+01:00

I implemented a quick hack today to extend an Active Record association such that you can define default attributes:

What we’re doing is extending the association proxy object with a module that overrides the build and create methods such that they use the default values returned by the default_attributes method. Much neater than setting them elsewhere, no?

I love this sort of meta-programming in Ruby, it’s so much nice than the way we used to do it in the bad old days using alias_method_chain.

3-Day Ruby and Rails Training Bootcamp Course in Manchester, UK

2011-06-29T00:00:00+01:00

What: 3-days intensive Ruby/Rails training for £360
When: August 17-19th
Where: The Manchester Digital Labratory

I’m pleased to announce that me and Ric Roberts will be running a 3-day Ruby and Rails Bootcamp training course at The MadLab here in Manchester, UK this August. It’s part of their Omniversity programme, aimed at offering affordable, professional training in subjects as diverse as Radio Production, Arduino/Physical Computing and Short Story Writing.

Our course aims to teach both the fundamentals of Ruby as well as the necessary skills and knowledge to build web applications using the Rails framework. It’s aimed at anyone who has experience in web development, but doesn’t require any previous Ruby or Rails experience. It’s priced at a very reasonable £360, including lunch and all the tea/coffee you can drink! So if you’ve always wanted to learn Ruby/Rails but have never managed to find the time/motivation to teach yourself, this is definitely the course for you. Find out more and sign up here.

MadLab – A Community Hack Space

I’m really happy that this course is happening at MadLab. For those that don’t know, it’s a community-run hack space in the centre of the city, aimed at bringing together geeks, artists, designers, hackers; basically anyone with a general interest in tinkering and being creative. It sprung up from nothing through the hard work and dedication of some good friends of mine and has quickly become the home for many of the local tech meet-ups and craft groups. On any one day, you are just as likely to come across the North West Ruby User Group meeting to discuss Coffee Script as you are the Writers Forum North presenting experimental writing or Fashion Hackers knitting and sewing to raise money for Oxfam. They’ve also recently secured funding for an exciting programme around DIY Bio. If you’ve not yet made it to the MadLab, I can heartily recommend a visit.

3D Secure in Rails with Active Merchant and Sage Pay (formally ProTX)

2009-07-01T00:00:00+01:00

The Pain That is 3D Secure

3D Secure is like the project manager of online payments: it’s meant to be helpful, but in reality it’s nothing but a pain in the ass. On the surface it provides a further level of authentication for consumers making online payments. Visa and Mastercard present it as a security enhancement that shifts liability away from merchants whilst also providing added safety to customers against fraud. Unfortunately it has been very poorly promoted, and manages to both confuse consumers and make the checkout process more complicated at the same time. As a result, merchant uptake has been slow, and despite regular threats from the card companies to make it compulsory, at the time of writing you can still take online payments without it. Well, almost — if you want to accept Maestro payments here in the UK, then chances are you’ll need to get them 3D Secured.

3D Secure Enabled Active Merchant for Sage Pay

To this end, I’ve forked Active Merchant and added 3D Secure Support to the ProTX gateway. Adding 3D Secure support to other gateways shouldn’t be too difficult. For some info on potential differences between how Sage Pay and other gateways do 3D Secure, see the end of this post.

Warning and Caveats

What follows is a rough guide on how you might perform 3D Secure authentication with Sage Pay. How you actually perform the authentication process will be application specific so don’t expect things to work if you blindly copy and paste the following code into your app. The aim is to give you enough of an overview of how the process works and how my fork provides the means to complete the steps required.

As part of that, I’m also assuming that you already understand and use Active Merchant for payment processing with Sage Pay and also have an understanding of the 3D Secure protocol itself. If not, there is plenty of information out there.

Finally, make sure you have good test coverage for your 3D Secure enabled code as this is a complex process with lots of potential pitfalls. To help you with this, the Bogus gateway has been updated with 3D Secure support too.

On to the Code

Firstly, once you have my fork from github, you need to enable 3D Secure on your Sage Pay test accounts administrator page:

You will need to pass in :enable_3d_secure => true when you instantiate your gateway:

Changes to the Response and Gateway

The Response object now behaves subtly differently. In standard Active Merchant, a Response will either be successful or not:

With 3D Secure enabled, an unsuccessful transaction hasn’t necessarily failed, it might simply require additional 3D Authentication:

In this case, the Response object will contain the additional parameters you need to perform 3D Authentication: the PaReq, MD and ACS Url.

You use these parameters to redirect the user to their issuing bank where they are asked to authenticate themselves by providing their password. Once they have completed authentication, the user is redirected back to your site with the results of the authentication, which you then have to send back to the gateway to ‘complete’ the transaction. You perform this with the gateway’s brand new three_d_complete method:

Makes sense so far? Don’t worry, it only gets more confusing…

Performing the 3D Authentication in Your App

Assuming you are doing things RESTfully, your 3D Secure enabled PaymentsController may end up looking something like this:

Here, my Payment model encapsulates the call to the gateway and processes the response to see if it was successful or requires further 3D authentication. If authentication is required, the controller renders an iframe, into which the three_d_form action is loaded which redirects the user to their issuing bank for authentication:

Here, the orange section is the iFrame with the bank’s authentication page loaded. The three_d_iframe view code looks something like this:

It generates a form that redirects the user to their issuing bank for authentication. As well as the PaReq and MD, the TermUrl is sent as the three_d_complete action where we want to receive the callback with the result:

Once/if the user completes authentication, they are redirected back to the three_d_complete action and we make the three_d_complete call back to the gateway to see if the transaction has been authorised or not (see the three_d_complete action in the controller code above).

Finally, we break out of the iframe by rendering either verification_complete or verification_failed, depending on the result of the three_d_complete call:

And:

When you want to skip 3D Secure

You can also force 3D Secure off on a per-transaction basis, simply pass :skip_3d_secure => true with your options when you call authorize or purchase. I use this on some sites to turn 3D Secure off for all except Maestro payments so as to minimise the risk of order abandonment.

Warnings and Caveats Again

Not to sound like a broken record, but let me re-iterate that although the above code demonstrates the basics of the authentication process, it is very much sudo-code and omits much of the app specific business logic that you will need in your models. Therefore, don’t expect a copy/paste job to work, and don’t forget to test, test and more test.

Implementing 3D Secure on Other Gateways

I was hoping that this work would form the basis for a generic implementation of 3D Secure in Active Merchant. Unfortunately it would appear that it’s not as straight forward as I’d imagined. It seems that Sage Pay has a slightly different approach to 3D Authentication compared to other gateways. Sage Pay requires you make a standard authorisation attempt and sends you a special response if 3D Authentication is required. You then authenticate the user and send the authentication result back to Sage Pay to ‘complete’ your original authorisation attempt.

Other gateways (Payflow Pro for example) have a slightly different approach, and require a call to an authenticate method before you attempt an authorisation to check if 3D Authentication is required. So you perform the authentication first, then make an authorisation call, sending the authentication results as well as the payment details. So unlike with Sage Pay, you need to send the users payment details twice, once for authenticate, then again for the authorisation.

These differences make a common API for 3D Authentication in Active Merchant tricky. One approach might be to encapsulate the authenticate call into the respective authorize and purchase methods, mirroring Sage Pays behaviour, and have the three_d_complete method make the authorisation calls as necessary. This would require some potentially messy conditional logic in the authorize and purchase methods and may not be the best approach.

I do have some ideas about how you could potentially make Sage Pay replicate the API of gateways like Payflow Pro. Unfortunately I haven’t managed to acquire a 3D Secure enabled Payflow Pro test account to try out this theory. If you can help out with this, drop me a line and who knows, maybe we can finally get a 3D Secure API into Active Merchant.

New in Rails 2.3 - Disabled option tags and lambdas for selecting and disabling options from collections

2009-03-06T00:00:00+00:00

As it seems to have slipped through the usual channels, I thought I’d document a couple of enhancements to the form option helpers here.

Disabled option tags

The form option helpers have been updated so that you can now specify disabled option tags:

Disabled option tags appear greyed out and cannot be selected by the user (or at least they do in normal browsers – see below).

Lambdas for selecting and disabling option tags from collections

You can now use anonymous functions to specify which members of a collection should be selected or disabled in the resultant option tags. For example, you may want to disable product sizes that are out of stock:

This works exactly the same for selecting values, simply pass your anonymous function in as :selected.

A word of caution – always coding defensively

Although disabled option tags are part of the HTML specification, Internet Explorer 6 and 7 do not support them and will display disabled option tags as selectable. And although there are hacks to get IE to behave, you can never guarantee that disabled values will not be submitted by someone constructing a html post. Therefor, it’s always best to code defensively and guard against the potential selection of disabled values in your controller actions.

Disabled option tags in rails forms

2009-01-05T00:00:00+00:00

Update: My patch has now been accepted into core, which means that as of Rails 2.3, this plugin should no longer be necessary. More details here.

Ever wanted to disable options in a form select in rails? I have; it feels more useable to me to disable out of stock product sizes:

The rails Form Option Helpers won’t let you do this as they currently stand. So until things change in core, I’ve put together the option_tags_will_disable plugin.

Simply specify the disabled values when calling options_for_select:

You can do the same when working with collections, but more interestingly, you can also give a Proc to identify which elements should be disabled:

And as an added bonus, selected options can also be identified with a Proc!

Rails gets some engines love

2008-11-26T00:00:00+00:00

No sooner is Rails 2.2 out the door than edge Rails gets exciting again!

A tasty little commit hints at some major changes to the way Rails handles plugins. Finally, the awesome features of the engines plugin (lovingly crafted by James Adams) will be creeping into core.

I’m not one to speculate what brought about the change in heart, I’m just glad Rails is finally drinking the engines Kool-Aid!

Engines? Wha?

As it says in the README: “The engines plugin enhances Rails’ own plugin framework, making it simple to share controllers, helpers, models, public, assets, routes and migrations in plugins”.

In a nutshell, you get to create slices of apps as plugins which makes it a piece of cake to to share common functionality between multiple applications. In my case, I’ve been able to put together several e-commerce websites with practically all the core functionality provided by a set of plugins. The beauty of it is, you can easily override views, actions, etc, in your app to make each site it’s own. And when you fix a bug, or add a new feature, all the sites can benefit!

What comes next?

It’s still early days and it’s not yet clear just how much of this is getting rolled into Rails, but James has hinted that much will make it across, including migrations, routes and asset management.

In the mean time, if you want to see what all the fuss is about, check out the engines plugin which, thanks to the hard work of everyone involved, now runs happily on Rails 2.2!

Update

The commits are coming thick and fast now. I’m certainly looking forward to road testing these new feature as they take shape.

Rails and git submodules can play nice

2008-08-11T00:00:00+01:00

I use git submodules to track plugins that I have under active development. This way, I can make changes to the main repository as well as the plugins with minimum fuss. There’s a great tutorial on working with submodules, which includes a couple of gotchas that may explain why submodules have got such a bad rep from some quarters.

Gotcha No. 1 – Always commit changes in your submodules before commiting your main repository

If you make any changes to a submodule, be sure to commit and publish these changes before you commit anything in the main repository, otherwise you and others will have issues trying to clone the repository.

Gotcha No 2 – Check you’re on a branch before making changes

If you are cloning a repo with a submodule and run git submodule init/update, be aware that the submodule has been checked out at a specific commit as apposed to the head of a branch meaning you have to checkout a branch before you make any changes.

Passenger/mod_rails 2.0 RC1

2008-06-12T00:00:00+01:00

The guys at Phusion have been hard at work improving mod_rails and a release candidate for 2.0 is now available. This includes: rack support; faster graceful restarts; less memory usage; fair load balancing; upload buffering; better stability and much more. Upgrade now for an instant win!

Update: if you have problems installing from the gem, get the latest version from github.

mod_rails and apache on OS X Leopard

2008-06-02T00:00:00+01:00

I was going to write up my experience rolling mod_rails on the default install of Apache to tidy up my development environment, but someone beat me to it!

There’s only one thing I did differently – I like to keep my apps in the Sites folder to keep things tidy – so in the spirit of keeping things DRY I won’t duplicate an already good write-up, but I will add a couple of points that caught me out.

Apache 2 and NameVirtualHost

If you find that Apache will only serve up the first of your virtual hosts, check you’ve correctly specified the NameVirtualHost directive.

Beware, FileVault and permissions

If you’re running FileVault, you might have a bit of fiddling to do with your file permissions.

Rails plugins and the move to gems

2008-05-31T00:00:00+01:00

This week, I made my first contribution to core which made installing plugins from git repositories over ssh work. It was a pretty small, mangy little patch – nothing more than fixing a typo in the end – but it felt good giving something back to a framework that has given me so much.

Now that I’m newly freelance, I’m hoping to be able to spend more time giving back to the Rails ecosystem, and the first port of call might have to be the plugin management system. I know plugins are becoming decidedly unfashionable with a lot of smart people saying they you should be using gems instead. And with the recent additions to rails this makes even more sense and you really should be removing those plugins from your apps in favour of loading them as gem dependencies. But in some scenarios, a plugin is all that will do.

In my case, I make use of the engines plugin (another unfashionable and often misunderstood bit of rails goodness) to share common application structure between a few apps, and here the whole plugin-as-gem thing just doesn’t fit.

Having been underwhelmed with the Piston equivalents for git, I’ve found myself using ./script/plugin install again, and although this now works with git repositories, ./script/plugin update doesn’t. Can it be that hard? Time to find out…

My blog is born

2008-05-27T00:00:00+01:00

Finally after much twiddling with WordPress themes (so glad I don’t work with php anymore) here is my new blog! Because every freelance Rails developer worth his salt needs a blog, right!?

Thanks to Sophie for the great design. Now all I need is some actual content…