Yesterday I just played around with PlayOnLinux install scripts. Previously I have successfully installed Heroes of Might and Magic 1 bought from GOG.com to my Linux box using PlayOnLinux.
There's no PlayOnLinux install script for this game at the moment and manual install is not that straightforward. I needed to tweak a bit on DOSBox configuration (yeah, GOG's HOMM1 uses DOSBox). Therefore I decided to make a script and hope it can be submited to PlayOnLinux website :) Still needs to adjust the script to follow their scripting standards but at least it works if you want to try:
Download the script here.
You can also track this script development at POL's forum here.
Wednesday, January 30, 2013
Tuesday, July 3, 2012
Tampilan baru Blog
Setelah sekian lama situs www.jar2.net dirombak dengan tampilan baru a.k.a. versi 7, akhirnya sempat juga (baca: menyempatkan diri) untuk update layout Blog supaya tampil selaras dengan websitenya.
Oke, langsung saja, memperkenalkan tampilan baru blog.jar2.net! Selamat membaca!
Oke, langsung saja, memperkenalkan tampilan baru blog.jar2.net! Selamat membaca!
Saturday, January 21, 2012
Creating a Login Page That Returns to The Last Visited Page in PHP
Today I gonna post a tutorial about how to create a login page which returns to the last visited (refering) page on success.
Usually we see on many websites that when we do a login process, the website redirects to its homepage or account page if the login is successful. Creating this is quite easy. But sometimes we also see some websites (such as YouTube) redirects its user to the last visited page after logging in.
The main idea is quite simple. When a user go to the login page, the page find out the URL where the user comes from (in PHP this can be achieved by checking $_SERVER['HTTP_REFERER'] variable). This information is passed alongside with user credentials (username and password) to the login process page. So when the login succeed, the page can redirect the user to the provided URL.
Okay now let's go into the business.
1. Create some pages.
In this tutorial we are going to make two simple pages that users can browse between them. Let's make the first page:
index.php
Note: To simplify the code, the above lines is not a valid HTML document. When making a real pages you should write all the HTML, HEAD, and BODY tags in the correct form
We have two links: login and logout. Either of this links will be displayed based on user's login state. When a user is logged in, the $_SESSION['is_logged_in'] is set to true. The session variable will be described later in this tutorial.
Next we make another page similar to the first one. You can just copy the file and make changes to its title to differentiate the latter from the first one.
page2.php
2. The Login Page.
We see that if we click on the "Click here to login" link, it will go to login.php. Now we make a simple login form with just username and password fields. But before that, we first check and get the URL where user comes from and assign it to a variable $redirect_to. We can know the information from $_SERVER['HTTP_REFERER'].
login.php
Okay, then goes the login form:
Inside the form we put a hidden value named "redirect_to" to pass the URL we get before to login_submit.php which will process the form.
Note: For you who are new to PHP, you can see that I write <?=$redirect_to?> as the value of the hidden field. That is the shorthand version to write PHP code which has the same meaning as <?php echo $redirect_to; ?>. Additionally you can also see an @ symbol before the variable name. This is used to surpress error messages (i.e. if we use/print the variable while it is unset).
3. The Login Process.
When a user clicks Login button, all the above data are sent to login_submit.php. In this file, we check for the username/password pair. If they match then the login is successful and we can go back to the last page. Otherwise the login form is displayed again with an error message.
For this example we will just check that user must enter "admin" as his username and password.
login_submit.php
Sometimes $_SERVER['HTTP_REFERER'] (or the $redirect_to variable in this case) may not contain any data. This event may occur when users are directly going to the login page by typing the URL in the address bar, for example. So we still need to check that if $redirect_to is empty, we just go to the homepage (index.php) as usual.
4. Bonus: The Logout Process.
So far, our login page tutorial should be finished here. But it's not complete if we don't also create the logout page. So as a bonus, here's the code for logout.php.
logout.php
The easiest way to logout is by destroying the session, so all the data inside $_SESSION will be cleared.
When users logout, we might also want them to return to their last visited page, so there we also check for $redirect_to variable. This goes the same way as the one in login_submit.php file.
Hope this tutorial helps! :)
» Download all the files here.
Usually we see on many websites that when we do a login process, the website redirects to its homepage or account page if the login is successful. Creating this is quite easy. But sometimes we also see some websites (such as YouTube) redirects its user to the last visited page after logging in.
The main idea is quite simple. When a user go to the login page, the page find out the URL where the user comes from (in PHP this can be achieved by checking $_SERVER['HTTP_REFERER'] variable). This information is passed alongside with user credentials (username and password) to the login process page. So when the login succeed, the page can redirect the user to the provided URL.
Okay now let's go into the business.
1. Create some pages.
In this tutorial we are going to make two simple pages that users can browse between them. Let's make the first page:
index.php
<php
// Check session state
session_start();
if($_SESSION['is_logged_in'] == true)
$logged_in = true;
else
$logged_in = false;
?>
<h1>This is The First Page</h1>
<a href="page2.php">Go to the second page</a>
<?php if($logged_in) : ?>
<p>You are logged in.</p>
<a href="logout.php">Click here to logout</a>
<?php else : ?>
<a href="login.php">Click here to login</a>
<?php endif; ?>
// Check session state
session_start();
if($_SESSION['is_logged_in'] == true)
$logged_in = true;
else
$logged_in = false;
?>
<h1>This is The First Page</h1>
<a href="page2.php">Go to the second page</a>
<?php if($logged_in) : ?>
<p>You are logged in.</p>
<a href="logout.php">Click here to logout</a>
<?php else : ?>
<a href="login.php">Click here to login</a>
<?php endif; ?>
Note: To simplify the code, the above lines is not a valid HTML document. When making a real pages you should write all the HTML, HEAD, and BODY tags in the correct form
We have two links: login and logout. Either of this links will be displayed based on user's login state. When a user is logged in, the $_SESSION['is_logged_in'] is set to true. The session variable will be described later in this tutorial.
Next we make another page similar to the first one. You can just copy the file and make changes to its title to differentiate the latter from the first one.
page2.php
<php
// Check session state
session_start();
if($_SESSION['is_logged_in'] == true)
$logged_in = true;
else
$logged_in = false;
?>
<h1>This is The Second Page</h1>
<a href="index.php">Go to the first page</a>
<?php if($logged_in) : ?>
<p>You are logged in.</p>
<a href="logout.php">Click here to logout</a>
<?php else : ?>
<a href="login.php">Click here to login</a>
<?php endif; ?>
// Check session state
session_start();
if($_SESSION['is_logged_in'] == true)
$logged_in = true;
else
$logged_in = false;
?>
<h1>This is The Second Page</h1>
<a href="index.php">Go to the first page</a>
<?php if($logged_in) : ?>
<p>You are logged in.</p>
<a href="logout.php">Click here to logout</a>
<?php else : ?>
<a href="login.php">Click here to login</a>
<?php endif; ?>
2. The Login Page.
We see that if we click on the "Click here to login" link, it will go to login.php. Now we make a simple login form with just username and password fields. But before that, we first check and get the URL where user comes from and assign it to a variable $redirect_to. We can know the information from $_SERVER['HTTP_REFERER'].
login.php
<?php
// Get the refering page (if unset)
if(!isset($redirect_to))
$redirect_to = $_SERVER['HTTP_REFERER'];
?>
// Get the refering page (if unset)
if(!isset($redirect_to))
$redirect_to = $_SERVER['HTTP_REFERER'];
?>
Okay, then goes the login form:
<h1>Login</h1>
<form action="login_submit.php" method="POST">
<label>
Username:<br />
<input type="text" name="username" value="<?=@$username?>" /><br />
</label>
<label>
Password:<br />
<input type="password" name="password" /><br />
</label>
<input type="submit" value="Login" />
<input type="hidden" name="redirect_to" value="<?=$redirect_to?>" />
</form>
<p><?=@$error?></p>
<form action="login_submit.php" method="POST">
<label>
Username:<br />
<input type="text" name="username" value="<?=@$username?>" /><br />
</label>
<label>
Password:<br />
<input type="password" name="password" /><br />
</label>
<input type="submit" value="Login" />
<input type="hidden" name="redirect_to" value="<?=$redirect_to?>" />
</form>
<p><?=@$error?></p>
Inside the form we put a hidden value named "redirect_to" to pass the URL we get before to login_submit.php which will process the form.
Note: For you who are new to PHP, you can see that I write <?=$redirect_to?> as the value of the hidden field. That is the shorthand version to write PHP code which has the same meaning as <?php echo $redirect_to; ?>. Additionally you can also see an @ symbol before the variable name. This is used to surpress error messages (i.e. if we use/print the variable while it is unset).
3. The Login Process.
When a user clicks Login button, all the above data are sent to login_submit.php. In this file, we check for the username/password pair. If they match then the login is successful and we can go back to the last page. Otherwise the login form is displayed again with an error message.
For this example we will just check that user must enter "admin" as his username and password.
login_submit.php
<?php
// Get form inputs
$username = $_POST['username'];
$password = $_POST['password'];
$redirect_to = $_POST['redirect_to'];
// Check login credentials
if($username == 'admin' && $password == 'admin') {
// Success
session_start();
$_SESSION['is_logged_in'] = true;
// If the last page is known, redirect to last page,
// otherwise go to home page.
if($redirect_to != '')
header('Location: '.$redirect_to);
else
header('Location: index.php');
}
else {
// When failure, reload the login form
$error = "Invalid username/password";
include('login.php');
}
?>
// Get form inputs
$username = $_POST['username'];
$password = $_POST['password'];
$redirect_to = $_POST['redirect_to'];
// Check login credentials
if($username == 'admin' && $password == 'admin') {
// Success
session_start();
$_SESSION['is_logged_in'] = true;
// If the last page is known, redirect to last page,
// otherwise go to home page.
if($redirect_to != '')
header('Location: '.$redirect_to);
else
header('Location: index.php');
}
else {
// When failure, reload the login form
$error = "Invalid username/password";
include('login.php');
}
?>
Sometimes $_SERVER['HTTP_REFERER'] (or the $redirect_to variable in this case) may not contain any data. This event may occur when users are directly going to the login page by typing the URL in the address bar, for example. So we still need to check that if $redirect_to is empty, we just go to the homepage (index.php) as usual.
4. Bonus: The Logout Process.
So far, our login page tutorial should be finished here. But it's not complete if we don't also create the logout page. So as a bonus, here's the code for logout.php.
logout.php
<?php
// Get the refering page
$redirect_to = $_SERVER['HTTP_REFERER'];
// Destroy session (logout)
session_start();
session_destroy();
// If the last page is known, redirect to last page,
// otherwise go to home page.
if($redirect_to != '')
header('Location: '.$redirect_to);
else
header('Location: index.php');
?>
// Get the refering page
$redirect_to = $_SERVER['HTTP_REFERER'];
// Destroy session (logout)
session_start();
session_destroy();
// If the last page is known, redirect to last page,
// otherwise go to home page.
if($redirect_to != '')
header('Location: '.$redirect_to);
else
header('Location: index.php');
?>
The easiest way to logout is by destroying the session, so all the data inside $_SESSION will be cleared.
When users logout, we might also want them to return to their last visited page, so there we also check for $redirect_to variable. This goes the same way as the one in login_submit.php file.
Hope this tutorial helps! :)
» Download all the files here.
Wednesday, December 14, 2011
Informasi Firmware Kamera Canon
Mungkin ini sudah bukan hal yang baru lagi untuk pengguna kamera Canon. Tapi tidak ada salahnya jika saya posting di sini. Jika pada ponsel ada "Tombol Khusus" untuk melihat nomor IMEI, data tanggal produksi, versi firmware, jumlah pemakaian dsb. dsb., rupanya di kamera pun ada "Tombol Khusus" tersebut untuk mengetahui versi firmware, jumlah pemotretan, kondisi alat, dan lainnya.
Berikut ini caranya.
Sebelum menekan "Tombol Khusus" ini, pertama-tama buat terlebih dahulu 2 File teks kosong dengan nama "vers.req" dan "ver.req". Simpan file ini di direktori root (tempat terluar) dari kartu memori. Kamera perlu mendeteksi keberadaan salah satu dari file ini (tergantung jenis kamera) untuk mengaktifkan fungsi "Tombol Khusus" tersebut.
Masukkan kartu memori ke kamera. Nyalakan kamera dan masuk ke mode PLAYBACK.
Tahan tombol FUNC/SET lalu tekan tombol DISP. Maka akan muncul keterangan jenis kamera, mode PAL/NTSC, serta versi firmware. Untuk informasi lainnya seperti jumlah pemotretan, informasi lensa, informasi driver dsb, tahan tombol FUNC/SET lalu tekan tombol DISP beberapa kali.
Pada Canon SX120IS, Informasi yang ditayangkan sebagai berikut:
Berikut ini caranya.
Sebelum menekan "Tombol Khusus" ini, pertama-tama buat terlebih dahulu 2 File teks kosong dengan nama "vers.req" dan "ver.req". Simpan file ini di direktori root (tempat terluar) dari kartu memori. Kamera perlu mendeteksi keberadaan salah satu dari file ini (tergantung jenis kamera) untuk mengaktifkan fungsi "Tombol Khusus" tersebut.
Masukkan kartu memori ke kamera. Nyalakan kamera dan masuk ke mode PLAYBACK.
Tahan tombol FUNC/SET lalu tekan tombol DISP. Maka akan muncul keterangan jenis kamera, mode PAL/NTSC, serta versi firmware. Untuk informasi lainnya seperti jumlah pemotretan, informasi lensa, informasi driver dsb, tahan tombol FUNC/SET lalu tekan tombol DISP beberapa kali.
Pada Canon SX120IS, Informasi yang ditayangkan sebagai berikut:
- (Semua layar)
Tipe Kamera
P-ID & PAL/NTSC
(Layar 1)
Firmware Ver
Tanggal
- (Layar 2)
Adj Ver.
ZoomLensEror
Tanggal
- (Layar 3)
Total Shoot
Zoom Retry Count
Mecha Condition
- (Layar 4)
Driver Info
Tuesday, November 1, 2011
Seberapa "Berat"-kah Bobot Skripsi Anda?
Kita tahu bahwa skripsi yang dibuat oleh mahasiswa di universitas-universitas sangat beragam baik dari segi topik dan isinya maupun bobotnya. Untuk topik tentu bisa segera diketahui dengan membaca judul dan pengantarnya. Tapi bagaimana cara mengetahui bobot dari skripsi tersebut? Berikut ini adalah salah satu caranya.
Tunggu dulu, bobot yang dimaksud dalam tulisan ini adalah bobot dengan makna tersurat. Jadi bukan mengenai kedalaman pembahasan isinya, tapi bobot yang sama artinya seperti menimbang bobot badan Anda. Atau dengan istilah fisikanya, berapakah massa dari skripsi tersebut?
Apabila merujuk pada aturan format penulisan skripsi di Binus, kertas yang digunakan adalah Quarto (Letter) 80 g/m2. Nah, dari jenis kertas ini sudah dapat diukur bobotnya. 80 g/m2 berarti dalam satu meter persegi (1m × 1m) massanya adalah 80 gram. Jadi untuk kertas Quarto yang berukuran 216 × 279 mm, massa per lembarnya adalah:
(0.216 × 0.279) × 80 = 4.82112 gram / lembar
Misalkan skripsi softcover terdiri dari 500 halaman, maka total massanya menjadi:
500 × 4.82112 = 2410.56 gram = 2.4 kg
Tentu saja nilai di atas hanya perkiraan, karena pada kenyataannya masih ada hal-hal lain yang mempengaruhi, seperti massa tinta dan sampul.
Jika Anda kurang terampil dalam hitung-menghitung, masih ada satu cara lain yang sangat mudah untuk mengetahui bobot skripsi. Mudah saja, cukup ambil satu jilid skripsi dan taruh di atas timbangan sayur. Selesai.
Tunggu dulu, bobot yang dimaksud dalam tulisan ini adalah bobot dengan makna tersurat. Jadi bukan mengenai kedalaman pembahasan isinya, tapi bobot yang sama artinya seperti menimbang bobot badan Anda. Atau dengan istilah fisikanya, berapakah massa dari skripsi tersebut?
Apabila merujuk pada aturan format penulisan skripsi di Binus, kertas yang digunakan adalah Quarto (Letter) 80 g/m2. Nah, dari jenis kertas ini sudah dapat diukur bobotnya. 80 g/m2 berarti dalam satu meter persegi (1m × 1m) massanya adalah 80 gram. Jadi untuk kertas Quarto yang berukuran 216 × 279 mm, massa per lembarnya adalah:
(0.216 × 0.279) × 80 = 4.82112 gram / lembar
Misalkan skripsi softcover terdiri dari 500 halaman, maka total massanya menjadi:
500 × 4.82112 = 2410.56 gram = 2.4 kg
Tentu saja nilai di atas hanya perkiraan, karena pada kenyataannya masih ada hal-hal lain yang mempengaruhi, seperti massa tinta dan sampul.
Jika Anda kurang terampil dalam hitung-menghitung, masih ada satu cara lain yang sangat mudah untuk mengetahui bobot skripsi. Mudah saja, cukup ambil satu jilid skripsi dan taruh di atas timbangan sayur. Selesai.
Wednesday, October 19, 2011
Mendapat Kurs Valuta Asing Terkini dengan PHP
Mendapatkan informasi nilai tukar valas (valuta asing) terbaru di internet sebenarnya tidaklah sulit. Ada banyak situs-situs perbankan di Indonesia yang menyediakan informasi kurs terkini, seperti di antaranya:
Karena situs-situs tersebut tidak menyediakan pilihan penyajian informasi dalam format yang programmer-friendly (misalnya JSON atau XML), maka cara yang bisa dilakukan adalah dengan melakukan parsing HTML.
Bagi Anda yang menggunakan PHP, hal ini bisa dilakukan dengan sebuah pustaka PHP untuk mendapatkan data kurs terbaru dari situs-situs perbankan yang terangkum dalam sebuah class KursValas. Unduh file-nya disini.
Cara penggunaannya pun mudah, misalkan kita ingin mendapatkan besaran kurs jual mata uang USD untuk transaksi yang diperoleh dari situs BCA:
Saat ini KursValas mampu membaca data dari situs BCA, BNI, dan Mandiri.
Beberapa catatan: Karena seluruh informasi kurs ini berasal dari situs eksternal, maka pustaka mungkin bisa menjadi tidak berfungsi sewaktu-waktu jika terjadi perubahan struktur layout halaman di situs tersebut.
KursValas ini menggunakan pustaka simple_html_dom.php yang dibuat oleh S.C. Chen dkk., dirilis dibawah lisensi MIT.
Download KursValas.php
http://files.jar2.net/scripts/php/kursvalas-1.3.src.zip
- Bank Indonesia
http://www.bi.go.id/web/id/Moneter2/Kurs+Bank+Indonesia/Kurs+Uang+Kertas+Asing/
http://www.bi.go.id/web/id/Moneter/Kurs+Bank+Indonesia/Kurs+Transaksi/ - Bank Central Asia (BCA)
http://www.klikbca.com/individual/silver/ind/rates.html - Bank Mandiri
www.bankmandiri.co.id/resource/kurs.asp - Bank Negara Indonesia (BNI)
http://www.bni.co.id/InfoKurs/tabid/287/Default.aspx
Karena situs-situs tersebut tidak menyediakan pilihan penyajian informasi dalam format yang programmer-friendly (misalnya JSON atau XML), maka cara yang bisa dilakukan adalah dengan melakukan parsing HTML.
Bagi Anda yang menggunakan PHP, hal ini bisa dilakukan dengan sebuah pustaka PHP untuk mendapatkan data kurs terbaru dari situs-situs perbankan yang terangkum dalam sebuah class KursValas. Unduh file-nya disini.
Cara penggunaannya pun mudah, misalkan kita ingin mendapatkan besaran kurs jual mata uang USD untuk transaksi yang diperoleh dari situs BCA:
<?php
require_once "kursvalas.php";
$kurs = new KursValas("bca", "trx");
echo "1 USD = Rp " . $kurs->get("USD", "sell");
?>
require_once "kursvalas.php";
$kurs = new KursValas("bca", "trx");
echo "1 USD = Rp " . $kurs->get("USD", "sell");
?>
Saat ini KursValas mampu membaca data dari situs BCA, BNI, dan Mandiri.
Beberapa catatan: Karena seluruh informasi kurs ini berasal dari situs eksternal, maka pustaka mungkin bisa menjadi tidak berfungsi sewaktu-waktu jika terjadi perubahan struktur layout halaman di situs tersebut.
KursValas ini menggunakan pustaka simple_html_dom.php yang dibuat oleh S.C. Chen dkk., dirilis dibawah lisensi MIT.
Download KursValas.php
http://files.jar2.net/scripts/php/kursvalas-1.3.src.zip
Wednesday, August 17, 2011
Wheel Color Picker 1.2 is Out!
Despite the two months age of the Wheel Color Picker plugin since its first debut, it is already used in various websites across countries. Therefore I am happy to announce the new release of jQuery Wheel Color Picker plugin! This new version adds some new exciting features and fixes:
Grab the package while it's hot directly from http://plugins.jquery.com/files/jquery.wheelcolorpicker-1.2.0.zip
For an online demonstration and documentation, please visit http://www.jar2.net/projects/jquery-wheelcolorpicker/demo.
There are still things to do to improve this plugin, such as adding HSL color format support, advanced color picker and so on. Let's look forward to have more new useful features implemented on the next release.
- Setting preset value is now supported. This can be achieved either by setting "value" attribute to inputs (e.g. < input class="colorpicker" value="FF0000" />) or adding "color" option when initializing (e.g. $('.colorpicker').wheelColorPicker({ color: "FF0000" }); ).
- Added "rgb%" (i.e. rgb(100%, 100%, 100%)) and "rgba%" (i.e. rgba(100%, 100%, 100%, 1) ) color formats.
- The color picker now supports alpha value. If you set color format option to "rgba" or "rgba%", the color picker dialog will come up with additional alpha slider on the right.
- Fixed a bug that giving undefined reference to rselectedColor error when using rgba format.
Grab the package while it's hot directly from http://plugins.jquery.com/files/jquery.wheelcolorpicker-1.2.0.zip
For an online demonstration and documentation, please visit http://www.jar2.net/projects/jquery-wheelcolorpicker/demo.
There are still things to do to improve this plugin, such as adding HSL color format support, advanced color picker and so on. Let's look forward to have more new useful features implemented on the next release.
Subscribe to:
Posts (Atom)