Notes on the web-development and artificial intelligence.
In the previous post I outlined the system’s specs and use cases. We also selected the primary use case we should start from – that is filtering screen.
Continue reading ‘Database structure and filtering approach. SMS Notification system.’ »
I’ve graduated in March 2010 and I don’t need to visit university any more. However, I enjoyed studying there and I know what challenges my fellow students-programmers have. That’s why I continue the job started this autumn – computer club, we call it “Geeks’ Club”. Sure, we’re not true geeks there, but we tend to be 
So I’m helping students who’re interested in web-technologies and in object-oriented programming. I explain them things that are not covered in the standard university course. Things, that are more practical and they can be paid money for.
Continue reading ‘Requirements and Use Cases. SMS Notification System.’ »
Most of the beginners and, sometimes, even more advanced programmers, want to develop everything from scratch because they want have control over the every aspect of their application. I entirely understand this tendency. When you learned how to program and you can code nearly anything you want (this relates more closely to scripting languages like php, perl, js etc), you start to do something global. Something that will change the world. This may be a new CMS, a new framework, new blog of e-commerce engine. And when you start this, you want to code it in the most efficient way, optimizing every little thing: every function, every SQL query. At the same time, you want to reuse the code you’re writing. So you tend to create more general solutions than you really need. And this slows down the performance. And again you go into optimization, limiting the possible uses to some extent.
Finally, if you finish your application, it may be faster or better than similar ones (however, usually it is the same or worse), but remember how much time you spent developing it. Yes, you’re proud of yourself – you’ve created your own DB abstraction layer, that handles SQL injections in a very smart way. You’ve also developed your own ORM engine, that goes nicely with your DB abstraction layer. It is quite likely, that you’ve already created your very own template engine and a nice JS library that makes animation very easy. Great job, my fellow programmer!
Continue reading ‘What is a framework and why you should use one?’ »
When designing some architecture, you face with the problem “which object should perform X task?” We discussed this question in my previous post in this series. There we noted, that object should perform the tasks he has enough info for. He should be an “expert”. But because one of the main OOP characteristics is interaction between objects, it’s often hard to answer this question.
Continue reading ‘Low Coupling and High Cohesion – GRASP (Design patterns series)’ »
Websites, that aggregate something become more and more popular because we need all information available in one place and accessed fast and easily. From time to time, you come across with tasks, that require retrieving some data from the password-protected area. For example, I use Guru.com for my job search. They post lots of the projects there, but they don’t offer convenient listing and filtering. So I developed my own tool, that grabs everything from there and ranks it all in the way I need. So, we’ll take a look at different types of password-protected areas and see how to deal with any of them
Continue reading ‘Grabbing password-protected content with cURL’ »
I bet you didn’t know, that switch can be used to answer the question: “Which of the N following statements is true?” Continue reading ‘Trick with php switch()’ »
As you know, PHP can return only one value from the function. However, there is a simple workaround – we return an indexed array from function and immediately split it into variables using list():
Once I had a task to import a number of data from datafeeds (that are in CSV or XML) into MySQL database. See solution in my another post. Here I want to tell about handling large files.
Datafeeds there are 50-200M each, so reading all file at once was not possible due to memory limitations. So we need to split it into portions. Here is the class, that solves the problem of downloading remote file, saving it locally and then reading by portions. Continue reading ‘Working with large files eficiently’ »
