Web Installer: The Code

The last two posts on web installer did not include any code. I wanted to dump all code into one post – this is it. Please note that this is what I did – you don’t have to copy my code as it is. Just look at the code and modify it according to your needs.

Getting Database Details

The Form/Frontend

<form action="" method="post">
<h1>Installation : Step 1</h1>
Please provide the database connection details...
<fieldset>
<legend>Database Details</legend>

<label for='host'>Database Host</label><input type='text' name='host' value='localhost' /><br />
<label for='db_user'>Database User</label><input type='text' name='db_user' value='root' /><br />
<label for='password'>Database Password</label><input type='text' name='password' /><br />
<label for='database'>Database</label><input type='text' name='database' value='nexty' /><br />
</fieldset>

<input type="hidden" name="step" value="2" /><br />
<input type="submit" name="action" value="Continue >>" /><br />
</form>

Backend

Make sure that the given database details are correct.

// The First step is Setting up Database connection
//					   (the '2' is NOT a typo)
if($_REQUEST['step'] == 2) {
	//Save the data to the Session
	if(isset($_REQUEST['host'])) $_SESSION['host'] = $_REQUEST['host'];
	if(isset($_REQUEST['db_user'])) $_SESSION['db_user'] = $_REQUEST['db_user'];
	if(isset($_REQUEST['password'])) $_SESSION['password'] = $_REQUEST['password'];
	if(isset($_REQUEST['database'])) $_SESSION['database'] = $_REQUEST['database'];
	if(isset($_REQUEST['url'])) $_SESSION['url'] = $_REQUEST['url'];

	if(mysql_connect($_SESSION['host'],$_SESSION['db_user'],$_SESSION['password'])) { //Try to connect to the DB.
		$QUERY['success'][] = 'Connection to Database server successful';

		if(mysql_select_db($_SESSION['database'])) {//Select the provided database.
			$QUERY['success'][] = "Database '$_SESSION[database]' selected";

		} else {
			$QUERY['error'][] = 'The given database('.$_SESSION['database'].') does not exist. Please povide a valid database.';
			$_REQUEST['step'] = 1;
		}
	} else {
		$QUERY['error'][] = 'Unable to connect to the database. Make sure that the entered details are correct';
		$_REQUEST['step'] = 1;
	}
}

Notice the over use of $_SESSION? That will come in use if I decide to add a Back button that enables the users to modify the data entered previously.

Database Creation

//Create the database only if it does not exist
//See if the database exists
$tables_sql = mysql_query("SHOW TABLES") or die(mysql_error());
$necessary_tables = array('Context','Project','Reminder','Setting','Task','TaskContext','User');
while($table = mysql_fetch_row($tables_sql)) {
	$necessary_tables = array_diff($necessary_tables,array($table[0])); //Remove the table from the array if it exists
}

//If there are no tables in the array that means that the all the necessary tables are present in the Database
//If some tables are missing, that means we have to create those tables...
if($necessary_tables) {
	$quries = <<<END
-- Insert all the SQL to create the necessary tables here...
END;

	//Execute all the queries
	$all_quires = explode(";",$quries);
	$query_count = 0;
	foreach($all_quires as $query) {
		$query = trim($query);
		if($query) {
			@mysql_query($query);
			$query_count++;
		}
	}
	$QUERY['success'][] = "Database Populated.";
} else {
	$QUERY['error'][] = "Tables already in Database - I did not overwrite it. If you want to remove the old data, please delete the tables and run the installer script agian.";
}

Saving the Database connection details


//I don't know how to escape the $ charector in heredocs - so I did this...
$config = '$config';//Heh, Heh ;-)
$system_installed = '$system_installed';
$configuration = <<<END
<?php
//Configuration file for Nexty
$system_installed = true;
$config = array(
	'db_host'		=>	'$_SESSION[host]',
	'db_user'		=>	'$_SESSION[db_user]',
	'db_password'	=>	'$_SESSION[password]',
	'db_database'	=>	'$_SESSION[database]',
	'url'			=>	'$_SESSION[url]',
	'absolute_path'	=>	'$abs'
);

END;
if(is_writable('../configuration.php')) {
        // ...Write the $config text into the configuration.php file...

	$QUERY['success'][] = 'Saved the configuration file. <a href="'.$_REQUEST['url'].'">Go to Nexty</a>';
} else {
	$QUERY['error'][] = 'Configuration file (configuration.php) is not writable. Please copy the configuration code and enter it into the "configuration.php" file. Then press continue.';
}

See the install folder for Nexty in the Subversion server.

About Binny V A 102 Articles
Freelance Web Developer on the LAMP Platform. Maintains a blogs http://blog.binnyva.com/. Other sites include Bin-Co and OpenJS

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