coder . cl

Managing changes is really important in software development projects. Each change should be handled carefully and must not be seen as part of the original development process. Instead, you should measure and control each change in the original requirements, even if you are using agile or cascade methodologies. You cannot accept all changes that the customer proposes without the proper management process. Is not that easy to handle changes in requirements like changing a comment in the code. Instead of accepting changes and delivering software without the proper management process, you should be able to handle those requirements using a standard method to manage those requirement changes.

Amazon S3 is a well known web based storage system provided as SaaS service provided by Amazon Web Services. On Django you can integrate that service using the storage interface called Django Storages, but you must have some considerations using that SaaS storage interface. Mainly regarding the Date header sent to the service on each read, write and similar operations, where you must send an updated header with the proper Time Zone and format.

So you feel as programmer because you can handle one programming language. Well, the bad news are the fact that you are not a programmer and even you don’t know too much about programming. At least you should know the three main programming paradigms, which comes from the two main branches called functional and imperative, so you should know at least functional, procedural and object oriented programming. The reason is quite simple, all languages are becoming hybrid languages supporting those three programming paradigms, if you do not understand their basic concepts, you are lost and messing the code.

How many times did get issues back with new bugs?. Do you think that is possible to avoid new bugs while you are coding or solving a bug related issue?. Probably is easy enough to consider that the application, depending on its architecture have several layers to observe. I do not mean layers at server side, but looking on a minimum layer overview, we have at least server side and client side, where both can be decomposed in data collecting and data processing, processed data display and presentation display, respectively.

Django provides an API to create custom template tags for those applications mounted over this nice Web Application Framework. Sometimes we need to decorate our functions, but you cannot decorate a function registered as tag in Django. The most elegant solution to solve this problem is to use a closure which will wrap the template tag function to be used decorated template tag.

JQuery is cool, it is a well known JavaScript framework that allows you to create DHTML nicely using selector and method goodies. The problem with jQuery, seems that some developers are messing the code a little bit, so many of them are using inline JavaScript to handle some events. This is a very bad practice, so you should centralise all events in JavaScript files, rather than placing the inline <script/> tag. So, the first step is to create a separate JavaScript files to leave a clean and plain HTML files on the server. Then you can handle a page specific configuration and jQuery event handlers using a very simple and object oriented technique.

As you know I am learning Haskell and doing small exercises based on the ACM ICPC problem archive. I am using those problem sets as my Haskell practice. The task presented on the problem 1991-c is related to a small DSL which handles concurrency simulations, using two simple instruction called lock and unlock to switch between running and ready states. The DSL defined for this problem seems to be simple. I have used the Parsec Haskell package to build the language parser. Where on my last post about this problem I have created the program parser, and now I build the interpreter.