Loading data from a file with PHP

In programming languages common tasks should be easy, and surprisingly often I find my self loading data from some source file into a database. With PHP loading a CSV file into the database – or posting the data to an API – is quite easy.

The only trick is to know the functions file_get_contents, split (and possibly list). The routine goes something like this:

$fileName = 'rawData.csv';
$content = file_get_contents($fileName);
$rows = split("\n", $content );
foreach ($rows as $row) {
	list($item1, $item2, item3) = split(';', $row);
	// Do something interesting...

The script gets the contents of file into a variable ($contents). Split the contents into an array ($rows) and the forach loop across each row. The first line of the loop splits the row into three fictitious items and the rest of the loop could do something interesting to the data read from the file.

I usually run scripts like these from the command-line (yes, you can do that with PHP scripts).

Code exit strategy – 3 tips

It seems many developers get stuck in the same systems maintaining the same code for years and years. While it may be a common phenomenon there are a few things you can do as a developer to avoid being trapped in your own code forever.

First make things readable.

While your brain may be wired to a system of only using single character variable and function names or naming global variables after your cats, no one else will get the system. Try to make all names as logical as you possible can. Making it easy to read the code – not only as syntax but also in the names used in classes, functions and other objects in your source, improves the likelihood that someone else can figure out what’s going on and inherit the code someday.

Second make the code do what it supposed to.

Sure it may be cool making the system a generic all-purpose Swiss army knife of software, but preparing the code for all sorts of functions with aren’t used and aren’t needed, it only cause confusion of the next developer trying to move your code forward. Objects and class hierarchies may be suitable in some cases, but sometimes it’s more wrapping and declarations than actual code – and you’re probably on a wrong path.

Third provide in-line documentation.

Documentation are like a ghosts – it probably doesn’t exist. Making pages of documentation is probably a neat way to spend time if your on billable hours, but if you’re a regular developer, documentation is – at best a necessary evil. Do try to provide brief relevant comments, when something complicated or “not too obvious” happens in the code. Don’t place small novels in the source, but short precise guidelines.

While the above tips doesn’t guarantee your freedom to move on to new exciting projects, it surely improves the odds dramatically when you code is inheritable and accessible by another developer.

PHP Coding Standards

If you’re part of a larger team developing (and sharing) code, it is a pretty good idea to have some common standards. In the PHP work, such a set of common standards include the PEAR Coding Standards. While it may be a challenge to agree on standards, it can be done – the hard part is following the standards.

One excellent tool to help you check for standards compliance is the PHP CodeSniffer. We’ve had it running for quite awhile and it seems to work as advertised. We’ve made our own (“TDC”) coding standards which is a variation over the PEAR coding standards, and checking if you follow them is as simple as running a simple command line.While it doesn’t enforce following of the coding standards, it does make it a no-brainer to check if you do follow the common standards.

The output from the codesniffer could look something like this:

mahler@mahler$ phpcs --standard=TDC Example.php

FILE: Example.php
[LINE 2] ERROR: "require_once" is a statement, not a function. No parentheses are required.
[LINE 5] ERROR: "require_once" is a statement, not a function. No parentheses are required.
[LINE 7] ERROR: Space before opening parenthesis of function call prohibited
[LINE 9] ERROR: Space before opening parenthesis of function call prohibited
[LINE 20] ERROR: Line indented incorrectly. Expected 0 tabs but found 1.
[LINE 49] ERROR: Line indented incorrectly. Expected 1 tabs but found 2.
[LINE 51] WARNING: Equals sign not aligned correctly. Expected 1 space, but found 2 spaces.
[LINE 59] ERROR: Space after opening parenthesis of function call prohibited
[LINE 61] ERROR: Line indented incorrectly. Expected 2 tabs but found 3.
[LINE 61] ERROR: Expected "while (...) {\n" found "while(...){\n".
[LINE 63] WARNING: Equals sign not aligned with surrounding assignments. Expected 3 spaces, but found 1 space.
[LINE 74] ERROR: Line indented incorrectly. Expected 1 tabs but found 2.

Do Repeat Yourself

It seems most developers has listen too much to the principle of “don’t repeat yourself”, and so otherwise bright developers in some cases strive too much to avoid repeating themselves and makes a mess of their systems but avoids repetitions completely. If your developer and reads about the DRY, do also remember the important step one: Think.
Continue reading Do Repeat Yourself