Kemarin tanggal berapa ya?
Kerja hari ini saya dihadapkan pada problem tanggal. Ceritanya, ada script yang harus diperbaiki. Karena metode yang digunakan berbeda dengan sebelumnya, akhirnya saya harus bermain-main dengan tanggal, atau lebih spesifik lagi, tanggal kemarin. Dari dulu, yang ada dikepala saya, kalau mengambil tanggal kemarin di PHP itu adalah mengambil dari fungsi mktime() yang dikombinasikan dengan date():
<?php $yesterday = date("Y-m-d", mktime(0,0,0,date("m"), date("d")-1, date("Y"))); ?>
Tapi, ada tapi-nya nih... Hari ini pikiran saya susah sekali untuk diajak kompromi, jadi saya sama sekali lupa pada metode simple diatas dan re-invent the whell. Sampai akhirnya saya menemukan bahwa untuk mendapatkan tanggal kemarin bisa dengan kode seperti berikut:
<?php $yesterday = date('Y-m-d', (strtotime($today) - (24*60*60))); ?>
Yang dioptimize menjadi:
<?php $yesterday = date('Y-m-d', (strtotime($today) - (86400))); ?>
. Tapi aneh, sampai disini saya tiba2 ingat metode pertama yang menimbulkan niat untuk menguji performa diantara metode tersebut, mana yang paling cepat.
Kemudian saya membuat script benchmark sederhana:
<?php
$total = 100000;
$today = date('Y-m-d');
$start1 = microtime(true);
for($i = 1; $i <= $total; $i++){
$yesterday = date("Y-m-d", mktime(0,0,0,date("m"), date("d")-1, date("Y")));
//$yesterday = date('Y-m-d', strtotime('-1 day', strtotime($today)));
}
$end1 = microtime(true);
//echo "$start1 - $end1\n";
$time1 = $end1 - $start1;
$start2 = microtime(true);
for($i = 1; $i <= $total; $i++){
$yesterday = date('Y-m-d', (strtotime($today) - (86400)));
}
$end2 = microtime(true);
//echo "$start2 - $end2\n";
$time2 = $end2 - $start2;
echo "Benchmark $total times.\n";
echo "Method 1: $time1\n";
echo "Method 2: $time2\n";
//echo "\n";
//echo "\n";
?>
Hasil yang didapat cukup membuat saya kaget. Ternyata ada gunanya juga sedikit pikun 
). Sebab, metode kedua mampu meningkatkan performa berkali lipat. Berikut output setelah 3 kali menjalankan script benchmark:
Benchmark 100000 times. Method 1: 27.5039460659 Method 2: 9.91087913513 Benchmark 100000 times. Method 1: 25.8903188705 Method 2: 9.55417895317 Benchmark 100000 times. Method 1: 36.927713871 Method 2: 14.1359829903
Dari sini bisa dilihatkan kalau metode kedua ternyata lebih cepat. Jadi, kalau lain waktu butuh metode untuk mengetahui tanggal kemarin, pergunakanlah metode kedua. Kalo ada yang lebih cepat lagi, kasih kabar ya!!!
Get Filename Without Extension
If you want to get the filename without extension in PHP, you can use this function :
<?php
function getFilenameWithoutExt($filename){
$pos = strripos($filename, '.');
if($pos === false){
return $filename;
}else{
return substr($filename, 0, $pos);
}
}
?>
Here's example on how to use it :
<?php
echo getFilenameWithoutExt('this_is_a_file.with_dot_on_it.txt');
//should generate output `this_is_a_file.with_dot_on_it`
?>
Get Selected Row from DataGridView
This is how to get selected row from DataGridView in .NET 2.0
- Make sure there's a single cell that is currently selected
- Get current row index using {datagridview instance}.CurrentCell.RowIdex
- Get the selected row using {datagridview instance}.Rows({current row index}).Cells({zero based index}).Value
Here's the sample code :
Dim crow = DataGridView1.CurrentCell.RowIndex
dim txt as string
Try
txt = DataGridView1.Rows(crow).Cells(0).Value & " || "
txt = txt & DataGridView1.Rows(crow).Cells(1).Value & " || "
txt = txt & DataGridView1.Rows(crow).Cells(2).Value
MessageBox.show (txt)
Catch ex As Exception
' do nothing
End Try
Get Current Directory from PHP
Yes, I'm lazy because if I want to manual, I'll find a method to find current directory instead of reinventing the wheel. Hehehe, so, here's what I do to find current directory :
echo dirname(__FILE__);
Now, I have new post for my blog 
.
Update: As comments from readers, you can also use getcwd() to get equal result.
Strange Javascript Behaviour
Yeah... I'm dumb. But, how do I know that this simple code generate quite difficult to understand error?
function buildParameter(scr, txt){
var returnValue = "";
var temp = txt.split("\n");
returnValue = '<?php echo '<?xml version="1.0" encoding="UTF-8"?>'; ?><request>'
+ '<script>' + scr + '</script>';
for(i = 0; i < temp.length; i++){
x = temp[i].split('=');
returnValue += '<param name="' + x[0] + '">' + x[1] + '</param>';
}
returnValue += '</request>';
alert(returnValue);
return returnValue;
}
Go a head, test it with your editor. Here, I got
unterminated string literal
And how do I know what is generating this error?. You know what? Here's the suspect :
returnValue = '<?php echo '<?xml version="1.0" encoding="UTF-8"?>'; ?><request>' + '<script>' + scr + '</script>';
I don't know why is this generating error and I'm googling without result. Maybe wrong query. But, I found the solution by trial and error. So, here's the weapon to terminate this suspect :
returnValue = '<?php echo '<?xml version="1.0" encoding="UTF-8"?>'; ?><request>' + '<' + 'script' + '>' + scr + '</' + 'script>';
Creating Dropdown Selector for Date Function
Sometimes, we need to create a form that need a date selection. Here's how I handle this thing. First, let us create some function to do this :
Active Input
Well, I think some of you confused while reading the title of the post. I just can't find any good word. The idea of this post is to show you how to create simple CSS to show which form input is active. You know, when working with so many input box, you'll sometime forgot what field you're working on. Even when there's cursor blinking on it.
So, here's what I usually do.
Using Try.these to make your javascript code robust
Hi there, this is yet another prototype tutorial. Today well learn a simple way to avoid error in our javascript code. We'll use Try.these method of prototype framework. So, how do we do this? First, we need to call the prototype library.
HOWTO : Lock Form Field
Sedikit coba-coba dengan event di javascript, akhirnya nemu satu trik sederhana untuk mengunci form agar tidak bisa di-edit tanpa menambahkan atribut readonly maupun disable.
Berikut caranya :
<form name="form">
<input type="text" size="12" onfocus="this.blur()" value="Locked text!" name="box" />
</form>
.
Perhatikan pada event onFocus, kita beri dia perintah this.blur(), sehingga field tersebut tidak pernah menerima focus.
