Tryangled Solutions web designing tips tricks

Frequently we query our database for a value but then have to always do the same manipulation on it before we can use it. Well it can often be useful to do this “once” in the database and then store the manipulated value in a separate column of the database.

Here is a very simple example
INSERT INTO tbl_name (col1,col2) VALUES(15,col1*3.14159);

Where col2 is set to the value of col1*pi

You could also do more complex calculation/filtering/shortening in your code eg php,ASP etc

“I can find what I need on Google” – Is this a common refrain amongst staff
and students in your college? Whilst Google is certainly far and away the
most commonly used search engine currently available, it is often not used in
the most effective way. There are many useful extras in Google that are
under-used, but which go towards making it a far more complete and effective
search tool than you would imagine. Here are some of the more interesting,
useful and quirky features that you might like to explore in order to get more
out of Google

A variable variable looks like this: $$var

So, if $var = ‘foo’ and $foo = ‘bar’ then $$var would contain the value ‘bar’ because $$var can be
thought of as $’foo’ which is simply $foo which has the value ‘bar’.

Variable variables sound like a cryptic a useless concept, but they can be useful sometimes. For
example, if we have a configuration file consisting of configuration directives and values in this
format:

foo=bar
abc=123
Then it is very easy to read this file and create corresponding variables:

<?php
$fp = fopen(’config.txt’,'r’);
while(true) {
$line = fgets($fp,80);
if(!feof($fp)) {
if($line[0]==’#’ || strlen($line)<2) continue;
list($name,$val)=explode(’=',$line,2);
$$name=trim($val);
} else break;
}
fclose($fp);
?>
Along the same lines as variable variables, you can create compound variables and variable
functions.

<?php
$str = ‘var’;
$var_toaster = “Hello World”;
echo ${$str.’_toaster’};
$str(); // Calls a function named var()
${$str.’_abc’}(); // Calls a function named var_abc()
?>

While debuggers exists, there isn’t much of a tradition for using them in PHP. People have largely come to rely on injecting debugging code directly into the program, for inspecting program scope. The infamous var_dump have served for this purpose and version 4.3.0 of PHP brought us another equally useful function — debug_backtrace.

Tracers and error handlers
Both of these functions produce a rather crude output though, so naturally people have written wrappers around them to remedy this. I think Harry’s pretty bluescreen was one of the first dedicated libraries I’ve seen. Xdebug spouts a similar output on error, although arguably not as pretty. Or blue.

What bluescreen is for debug_backtrace, krumo is for var_dump. Recently, FirePHP — building on Firebug — does a similar thing. FirePHP uses HTTP-headers to send data from server to client, which turns out to be very handy when dealing with non-HTML output (Eg. Ajax stuff). Because it builds on Firebug, it only works on Firefox, and in particular only on Firefox 2 (Another reason for Ubuntu-users to downgrade from Firefox 3).

Frameworks
Apart for these general general tracing tools, a couple of frameworks have their own, more or less specific, tools. Symfony’s Debug Toolbar is probably the most impressive …

This is an easy way to get to the folders on your system without having to open a Windows Explorer Window every time you want to access files. I find it very useful to have this feature as it allows me to access my Folders and Drives immediately and saves me a lot of time.

This works in Windows XP:

1. Right Click an empty spot on your Taskbar (Between your Start Button and your System Tray).
2. Click Toolbars.
3. Click New Toolbar.
4. A Small Window will Open that allows you to pick the folder you wish to make a Toolbar. If you want to access your Desktop Without having to minimize all your windows. Just Pick Desktop. If you want to access ONLY your My Documents Folder, Select that. Any folder will work for this.
5. Click OK.
The New Tool bar will appear at the bottom of your screen next to your System Tray.

If you find this to be not useful, Repeat Steps 1 and 2 and then check click the Toolbar you created that has a check mark next to it. And it will disappear.