When teaching Object Orientation, we go through the mechanisms of the language, and application design (see "Designing your applications using UML techniques"). And I cover a little - a very little - about design patterns. Delegates need to be aware of them, but a course that included a deep study of design methodology and patterns would be extended from what we currently offer by at least a day, with delegates who are converting from another OO language finding that the extra time was mostly revision.

However, last week's PHP Course ran quickly - bright delegates, all starting with more experience that our stated prerequisites, and in the training room 30 from 30 minutes before class officially started each morning. So we got on to the mechanisms of OO programming in PHP on the final afternoon of the main course, rather than starting it in the official way on the Friday morning. Which gave me time to talk about UML techniques in more detail, and to add in some more coverage of Design Patterns than is usual.

In a new source code example ([here]), you'll find a number of design patterns in use - some being commonly accepted / named ones, others which are our / my own patterns.

There's a factory pattern which takes raw data and creates an object from it. A factory differs from a constructor in that it often has to do preliminary work on the data, and indeed it can return objects of different types depending on the data actually passed in, and indeed it can return an array / list / hash / dictionary of objects. A factory method is a static method, provided within a class to place the logic of interpretting the incoming data source into objects, even prior to the creation of any objects.

There's a comparator pattern, which compares two objects. Static (class) methods can work on the data for all objects in a class, dynamic (object) methods work on a single object. Yet so often you want to compare two objects. Which is the larger? Which is the older? And that's where you'll use a comparator design pattern.

As an extension of the comparator, we often use a standard (static) pattern to find the largest or oldest - no formal name for this one, but you'll find an example called "longest" in the source example.

We've also got an example of a very simple getter pattern to retreive a property, but this particular example didn't use some of the other common design patterns such as setter and singleton. That's fairly typical - you'll use design patterns for the standard stuff, and then your own (or modified) code beyond that to add the functionallity that's unique to your data and the application thereof.

I spoke earlier about the decision we've had to take at Well House Consultants as to how far we go along teaching design methodologies and design patterns in our programming language courses. I believe we have the mix about right for most delegates who come on public courses. But if you're looking to learn about object orientation in Perl, PHP, Python, Ruby or C++, and would like an extra day or two covering the topics I describle in this article, please ask. We can usually (diary permitting) add an extra day onto the end of our courses to cover the subjects. Typically, it will be a private course - and we'll only charge you as if it was another day on the public course. A bargain way to learn about designing your application, and learn about it in the language that you'll be using!

UML (Unified Modelling Language) is a way of drawing (modelling) a system through a series of diagrams of different types - there are 7 basic types - and there are various software packages that can help you. But to go the whole hog and use them all on a small system is overkill, and on courses I often suggest to delegates it's far more practical to think things through and to know that you could draw the diagrams, rather than to draw them all with all the formally designated shapes and symbols. For an application I specified and started to write yesterday, I drew some example diagrams, which I'll share with you here.

The application requirement is to analyse a day's web server log files and extract information from them about the types and lengths of visits (a typically woolly or fluffy initial spec). Let's draw some diagrams ...

The Use Case diagram. "Where does the data come from, where does it go, and who provides it / who requires the answers". Where "who" is a job role, rather than an individual's name. The application that I started to write is indicated by the red arrow - taking the log files and provding a management / decision helping report.

The Object diagrams. For each of the data types (objects), we're defining what the contain - what other objects, how many of them, etc. In this example, we're defining a "visit" as containing one or more "requests". Each visit will contain one "browser" object and one "ip" object.

Class diagrams. Where data types have subclasses / other subsidiary types, you'll need to work out your interitance tree. In this example, website access requests within a visit are divided into "request" objects which are specifically requested by a visiting user, and "require" objects which are called up within a page by a request - that's accesses for things like style sheets and embedded images.

Sequence diagrams. When the application (or a part of it) is run, what actually happens? In this example diagram, a browser calls up a web server via the http protocol. The server application may call up an SQL database, or it may use data it already has (cached?) on the local disc and not use the database stage. This diagram helps you spot bottlenecks, and provides you with a route to finding what's happened if the application fails to run to completion.

The Deployement diagram. This shows you all the tools that you need, how you go from test and development system through to pre-production systems, the live system, and on to backups. It will include things like the source code control system that you use, and provide you with an indication of how you can roll back if some thing goes wrong, and an assurance that (if you follow the diagrams) that you really do have a backup of everything so that you can roll back.

State diagrams. For each type of object - what creates it, and what happens when it's finished with. And what happens in between. If calculations are done, is that as the object is set up, or as the results are needed? Are results cached? ... for more complex objects (such as sessions in a shopping cart), what's the page the object owner - shopper - is currently on?

Procedural diagrams. Also known as "flow charts" ;-) ... a diagram of the operation of each method. Procedural diagrams can be converted to actual code on some of the more sophisticated UML tools.

When you're learning Object Oriented Programming, you really need to learn the syntax and principles of the language elements, and also how to design to make best use of those elements. These diagrams - informally or formally - provide you help with the design.

There's a code example - a first (and incomplete) example showing code to support some of the diagrams above [here] from yesterday's Object Oriented Programming in PHP course.

The field that backs onto the Spa houses is enjoyed by many dog walkers. It was quiet at 07:30, but tracks in the snow showed us that we were far from the first.

That's Gypsy

and that's Billy!

Even in London, some snow was settling

Chippenham Station at Mindinght-10 ... a delayed 22:15 from Paddington drops off passengers on a slippery platform

The station car park - vehicles of the stragglers, and perhaps of those who have decided to stay in town overnight

The A350 - the road to Melksham - as you don't usually see it

It's now daylight, and snow is still settled. A quick check reassures me that our team, even through the snow, made it to work on time and breakfast will already be served in a toast room at Well House Manor - our delegate, business and leisure guest hotel here in Melksham.

This SCOB membership makes me intensely busy - we met in full last week and will do so again next week. I have a meeting on Saturday afternoon, another on Monday evening and that one I mentioned yesterday (Tuesday). And I'll be at a meeting with a SCOB element tonight too. It's been like this for a while, and will continue to be so. BUT questions like "What is the SCOB?" and statements like "Never heard of you" are all too common. And that's not really a surprise - after all, how do you reach everyone?

To make it far easier for people to find out what's going on, and for people to be able to make inputs, the SCOB is starting a website, in the format of a blog where all the SCOB members can post. Comments will be accepted - and indeed encouraged - to allow inputs from anyone, and we'll be providing "Open question" posts so that anyone can raise anything they wish. Of course, it's not "one size fits all". The website is at http://www.melkshamcampus-scob.org.uk/. There is already information being provided to users at some existing sites and to groups and individuals who are interested, the press is being informed (and we have excelllent local press in Melksham), and more will follow.

My answer to the person who said "Never heard of you" is "you have now" ... that's good. It's even better because we're able to start a conversation - we have a route through which we can reach you, and a route through which you can make comments and ask questions.

3rd February 2012

404, The Spa,
Melksham,
Wiltshire,
SN12 6QL.

Dear Neighbour,

I've received a letter, forwarded to me by the secretary of the Melksham Chamber of Commerce, concerning plans for "Land to the east of Spa Road, Melksham", and talking of it as "the most appropriate locations for up to 400 dwellings". As the letter is an open one, I've put in on my website at:
  http://www.wellho.net/graham/Hallam.pdf

Trying to work out the limits of the land, I believe that they're talking about "site 265" in Wiltshre Council's Strategic housing land availability assessment. That document is online at:
  http://www.wiltshire.gov.uk/planninganddevelopment/planningpolicy/strategichousinglandavailabilityassessment.htm
with the maps for Melksham at:
  http://www.wiltshire.gov.uk/planning-shlaa-2011-dec-appendix-3-melksham.pdf

The letter invites the community to attend an exhibition on 16th February - I'm writing to you today to make sure you're aware of it and can attend too if you wish, as I hadn't heard of it otherwise even though the plans have land adjoining our property shown as part of the potential site. And please feel free to circulate this letter.

Graham Ellis

Please feel free to email me (graham@wellho.net), call (01225 708225), drop a note through our door or pop round if you would like filling in on what I have researched. If you don't want to have to type in these horrid long web page names, this letter with links is at http://wellho.info/3602

But did I expect it would turn into something that I could grouch about from the start. Well - frankly - yes. For I'm traveling from Melksham, and for my 18:30 appointment in London, I would have had to catch the 07:17 train and would have arrived some 9 hours early. So instead I drove up to Chippenham, from where I had a prebooked ticket for the 15:55. For those of you who don't know the area, Melksham is a town with a population of around 24,000 and Chippenham has around 35,000. Melksham has two trains per day in each direction; Chippenham has two trains per hour in each direction.

I paid the usual leg and two arms to park at Chippenham Station. Did you realise that in the Western region of the UK, Car Parking and refreshments account for 12% of the Train Operator's income (it's just 7.5% in the next area across)? I mused that my 7.10 is far easier money for the train operators than running a train to Melksham - much cheaper for them to provide a patch of tarmac than a train, after all, and they charge the same. Smart business.

Anyway - my ticket was prebooked and waiting for me in the Ticket Vending Machine, which I successfully negotiated - with about 15 minutes to spare. Yes - tickets and seat reservations for the 15:55. Then I heard an announcement that the delayed 15:25 had just arrived in and, glancing up at the departure board, was shocked to see that the 15:55 showed as cancelled. That's right - I had just seconds before been issued with a train-specific ticket for a train that wasn't running.

A quick dash over the bridge (pushing through the crowds coming towards me, and probably appearing terribly rude and thoughtless) and I got onto the platform as the station staff were closing the doors. "I have an advanced ticket for the 15:55 that's cancelled - please may I use this train?" and the uniformed station person held the door open for me and I got on. I'm now seated on the train, either 15 minutes late or 15 early depending on how you like to think of it and ...

... Train Manager has just come by and checked tickets. I was slightly nervous bearing in mind the dire threats about being on the wrong train that I hear and read so often. However, he was "nice as pie" about it - helped that there was obviously some joined up data around and he knew the train behind wasn't running!

It's very curious this business of tickets that are for a fixed train, of course. If we (the customers) miss the train - even if it's because a bus run by the same company was late - we loose our money. But if the train operator cancels the train, he can just laugh it off and put us (usually) on the following service. The words "level playing field" come to my mind, but with a heavy dose of irony attached.

I didn't expect to start this post with a tale of things going wrong today - but I was going to comment on how I travel between Melksham and the west of England and many other parts of the country by train ... and how it always seems to be the Western legs that are "eventful" [I'm still writing on the train, and we have lurched over the points onto the slow lines ... what now, I wonder ...]

Payment by cheque has faded, to be largely replaced by BACS transfers, and the use of credit and debit cards has grown. MasterCard, American Express and Visa each represents a significant part of our business now. Each of the credit card companies has differences in its schemes, and as merchants some of these differences used to have a big effect on which we preferred. But I'm delighted to report that this imbalance of features and charges has now shrunk and balanced out, and we truly welcome payment on any of these cards.

You'll note little mention of cash. Yes, of course people who drop in to Well House Manor for a cup of coffee at £1.50 (open every day!) will typically pay by cash, and occasionally people will pay cash for Hotel Rooms too - but it's very rare indeed for a training course to be paid for with cash - I'm not saying it hasn't happened, but the few occasions are memorable ones.

The original map is dated 1888, and the overlay that's starting to burst through here is more or less up to date. It's very interesting to see how the course of the river was adjusted when the bypass was built ...

Without bundling up all the source images and much more, I can't publish the full application development resources here - but I HAVE included the view controller header file and the view controller source in our resources.

A couple of days ago, I was looking for a couple of people to learn with me / help me check my understanding of iPad programming in a few weeks time - see [here]. Looks like we're on for the weekend of 10th and 11th March, with a group of four of us shaking out XCode and Objective C, and making sure we've got a thorough understanding. That weekend's going to have quite an advanced starting level. It should leave me well prepared for iPad programming, with (perhaps) an ability to show others how to do so more formally later in the year.

iPhone programming is very similar to iPad programming - in fact you can choose to write Universal applications that run on both. Screen layout / resolution need to be considered, of course - but then that's the case even with iPhone alone where you have the original resolution and the newer, higher "retina" resolution. Here's another simulator screen capture, this time showing a simple iPhone text entry screen, with feedback of the text entered via labels modified by the controller. The View Controller Header file is [here] and the View Controller source in Objective C is [here]. Although I used IB (the Interface Builder) to create the layout rather than coding it directly, I have also included the interface design XML in my sample sources - it's [here].

However, I was very agreeably surprised by the event. It was well organised, it provided a good opportunity to honour some of the people and groups who have quietly done really good things for the town over the past year, and it provided a needed chance to catch up with some of the people we don't see often, and to meet new people for the (hopefully) common good into the future.

One of the Civic Awards was made to the Melksham Railway Development Group - with the Mayor (Councilor Rod Eaton) describing how the group promoted rail travel last year, with really successful trains to the seaside at Weymouth in the summer, and a trip with Santa in the lead up to Christmas. The award was accepted by one of the stalwarts of the group - Sion Bretton, who's their secretary (and I would like to add a mention of honour for the group's chairman, Peter Blackburn and for John Money their appropriately named treasurer).

Because of a personal interest, I'm very much aware of just how much the rail groups have achieved in the last year. I have no doubt that each of the other 7 award recipients has also done a very great deal in their field - that's a strength of Melksham. I am going to mention Andrew Morgan, too, who has been deputy Town Clerk for several years. Andrew's moving to Cornwall and Friday was his last evening. Staff are not eligible for awards, and so it was really good to see Rod giving a special "Thank You" to Andrew who will be a very hard act to follow. Andrew - all the best for the future.

It must be very difficult to get the balance right when planning an event such as this. Many of the attendees were guests of honour, and the Civic Award winners were also honoured guests, which means that it would be rather cheeky to ask them to pay (and indeed, chances are that many would elect not to attend). But on the other hand, costs can be high for an event with a meal, wine, a band, hall hire and the rest, and if it's not being paid for by the honoured guests, then either the remaining guests or the organisers (the Town Council, funded by the local taxpayers) must pay. And I have misgivings about the taxpayer funding a "jolly".

It must be difficult to get the balance right - but I think the Town Council team did get it right. The hall in which the event was held was their own. The food was a Hog Roast, followed by a simple cake and cream - excellent food, but pork in a bun followed by a slice of cake isn't like giving away a full meal which would be more traditional for a dinner / dance type event. And although drinks were provided to accompany the main course, the pay bar was open for supplements. And non-honoured guests *did* pay £15.00 for their places at the event.

Come mid-evening, the lights were lowered, the band struck up, and (sorry !) all chance of conversation ceased. I like music - but not that loud - each to his or her own taste. But if that's what it takes to pull in the people who are needed to make the earlier business part of the evening, so be it.

With two anxious dogs at home (Billy is still settling in and shouldn't be left for too long), we made our apologies and left - wishing everyone else a good time through to carriages at midnight. I would have said "we left quietly", except that we had to run the gauntlet of smokers clustering around the front door and, interestingly, continuing their networking. But we feel very much amongst friends who know us here, and really there's no need for us to sneak out. Our friends are very much aware of our "lark" rather than "owl" lifestyles, and know that we're up at the crack of dawn to walk the dogs.

Some places such as the image to the right are ... right in our Shopping Centre - the "High Street". Fairies Wear Boots Designs - right on the roundabout at the entrance to Sainsbury's, make original painted and engraved glassware. Their business card says "Fine Art, Handpainted & engraved glass, gifts for special occasions, weddings and corporate events". Why not pop in and see them if you're local - I certainly learned something new about our High Street yesterday when I popped in there, and although I (personally, at present) don't have a requirement for their product, I may do in the future - and I can tell people about them too.

The image on the left is our own Hotel / Training centre. We have niche products too - we're one of the very few providers of Tcl/Tk training courses in Europe, and of Lua courses worldwide. We're NOT in the town centre - we're about 200 yards from the Market Square, in an area where we have been able to provide plenty of free parking for our customers on site. And we offer many other products that are less niche too like High standard hotel and business conference accommodation. We too welcome people to walk in - we'll happily chat and show you around ... and did you know that we're open, 7 days a week, for bean to cup coffee, light snacks, and the rest. You'll always get a warm welcome.

A web page such as this one cannot give full show to all the wonderful products - be they an original painting of Lacock Abbey, a Perl course, bespoke engraved glassware with a unicorn theme, or tutorship in how to write and distribute applications for mobile phones and tablets. It can just hint at what's available. It's a taster. We may be able to tempt you further with more pictures ...

... and we may persuade you to click on those images to see them larger (as will happen with most images on this page) or to take you to more detailed pages which will tell you much more about the product (which will happen with one or two of them), and perhaps let you purchase online.

Hotel rooms certainly CAN be booked online ([via this link]), and we're delighted to offer immediate confirmation of availability, and best prices. Training course are also bookable on line [via this link], though we prefer to check with each individual by email first to make sure that they're buying the most appropriate course to meet their needs. And in the case of both hotel and courses, we look forward to meeting you in Melksham in due course.

With physical products rather than person-to-person services (such as those from Fairies Wear Boots Designs), you may wish to visit their shop - meet the owners, choose want you want ... but you may also live a long way away and for purely practical reasons wish to look through their web site, contact them through that (link [here]), and order and have your product shipped without ever setting foot in Wiltshire. And that's welcomed and cared for business too.

Melksham has a number of niche suppliers. Lisa and I were amazed to come up with some 200 retail product or service outlets when we came up with a map a couple of years ago. And we know that many of them are selling far and wide beyond the town via the Web. That's wonderful news for them, and for Melksham. Long may it be fostered, and continue to grow.

Some time in mid to late February, or early March, I'm going to take a day or two to check and see how I'm doing. And I'm going to check my knowledge by explaining to one or two former delegates / friends how it works - it's a real chance for them to learn with me, to be my guinea pigs if you like. If you would like to get into App writing for Apple products, and have a strong background in programming (including OO - principles at least), please let me know. (This is not going to be a beginner's session)

This is a real opportunity for you and me to help each other get really into this exciting field. I'm motivated - are you? Email me, or get in touch via our contact page.

[Venue - Melksham, Wiltshire. Hotel rooms available [here]. No charge at all for being my guinea pigs - but if you need to stay, we can't do the rooms for free as well - £72.00 per room per night which is our lowest delegate rate]

London, late afternoon and early evening yesterday

I'm studying again at present - not locally, but not at one of the more exotic locations - I'm back at the University where I took my degree course, graduating some 36 years ago. It's rather an odd feeling. I'm learning a new operating system - ios - and specifically programming under it. That will get me much more up to speed on iPad and iPhone programming. The course is spread over 10 evenings over as many weeks, and from my first attendance today I know it's very much lecture style, with the tutor covering a huge amount of ground in 2 hours, and all his students needing to find time before the following week to revise, practise, and come up with questions for the following week.

Why this departure from server side programming? Because the world is wider than server side programming. And it turns out that, hidden under the layers of apple and pastry, is a container that's based on a GUI (Graphic User Interface) with much the same concepts as Tk, and a language in Objective C that's object oriented just as C++ or Python, with a widget interface that's reminiscent of Swing (Java) or wX [Python]. And with some bits of the language, I'm thinking "goodness - that's almost like Tcl or Lua".

The best way for me to learn is for me to write notes - "what if I was telling someone else how to do this" - and that's what I'm planning to do. And I'll be hoping to go deep enough to be able to answer corollaries such as "what have I missed / why didn't it work" and "how do I xxx" where xxx is something a bit different. You'll see the fruits of my learning in a few months, I expect. We have a couple of iPad applications in mind, and one of the things that I've already learned today is that with care you can write an application for both the iPhone and the iPad. The two headlines to bear in mind are (1) the different aspect ratio and (2) if you build the two as one, you can't sell them twice to someone who wants them for both device types, nor have a differential pricing scheme. Well - that's what we were told. I'm going to suggest that screen size makes a significant difference too. Over the past couple of weeks, I've been tailoring web content for iPhone and iPad - and that's something that I've already learned to be very significant.

It rather looks like this isn't the big departure for us that you might have imagined. Rather a gentle introduction of a new track. Objective C's actually a rather nice language ...