Archive for the ‘PHP’ Category

Jun20

PHP template engines and why they’re useless

For the past 4 or 5 years I’ve been a proponent of using PHP as it’s own template engine. I cringe every time I see someone using smarty, btemplate, fastTemplate, etc… because I’ve never had to do anything in my html that couldn’t be done with PHP. Never! Why add a layer to your app if you don’t have to?

To illustrate this I’m going to show you a template written in a template engine, and then in PHP.

Here’s an example from the Smarty website

<table border="0" width="300">
    <tr>
        <th colspan="2" bgcolor="#d1d1d1">Guestbook Entries (<a href="{$SCRIPT_NAME}?action=add">add</a>)</th>
    </tr>
    {foreach from=$data item="entry"}
        <tr bgcolor="{cycle values="#dedede,#eeeeee" advance=false}">
            <td>{$entry.Name|escape}</td>        
            <td align="right">{$entry.EntryDate|date_format:"%e %b, %Y %H:%M:%S"}</td>        
        </tr>
        <tr>
            <td colspan="2" bgcolor="{cycle values="#dedede,#eeeeee"}">{$entry.Comment|escape}</td>
        </tr>
    {foreachelse}
        <tr>
            <td colspan="2">No records</td>
        </tr>
    {/foreach}
</table>

Here’s an example using PHP. e() is an escaping function you write yourself.

<table border="0" width="300">
    <tr>
        <th colspan="2" bgcolor="#d1d1d1">Guestbook Entries (<a href="{$SCRIPT_NAME}?action=add">add</a>)</th>
    </tr>
    <?php if ( count( $data ) ): ?>
    <?php foreach( $data as $entry ): ?>
        <tr bgcolor="<?php if( $i++ % 2 ): ?>#dedede<?php else: ?>#eeeeee<?php endif; ?>">
            <td><?= e( $entry['name'] ) ?></td>        
            <td align="right"><?= date( $entry['entryDate'], 'e b Y H M S' ) ?></td>        
        </tr>
        <tr>
            <td colspan="2" bgcolor="<?php if( $i % 2 ): ?>#dedede<?php else: ?>#eeeeee<?php endif; ?>"><?= e( $entry['comment'] ) ?></td>
        </tr>
     <?php endforeach; ?>
     <?php else: ?>
        <tr>
            <td colspan="2">No records</td>
        </tr>
     <?php endif; ?>
</table>

As you can see there is only 2 added lines of code. I had to add an if statement to account for smarty’s foreachelse. No added layer. No extra work for the interpreter. Just as readable (unless you’re a developer, then it will be more readable)

In closing read this post on the sitepoint forums. Pay particular attention to Voostind’s replies (#1, #2, #3)

Jun12

Merge query string

Ever have a url like this…

index.php?dosearch=true&page=1&search[co_name]=best+buy&search[address1]=12+main+st&search[city]=bridgeport&search[state_province_abbrev]=ct

…and wanted to create a link that would go to page=2, but keep the rest of the query string?

This recently happened to me so I created a function. Normally this would be a trivial call to array_merge, but I needed it to handle single-level arrays too.

I present to you mergeQuery

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function mergeQuery( $link ) {
 
	parse_str( $_SERVER['QUERY_STRING'], $qry );
	parse_str( $link, $lnk );
	$mergedQry = array_merge( $qry, $lnk );
 
	foreach( $mergedQry as $var => &$val ) {
 
		if ( is_array( $val ) ) {
			foreach ( $val as $val_k => $val_v ) {
				$finalQry .= sprintf( '%s[%s]=%s&', $var, $val_k, $val_v );
			}
		}
		else {
			$finalQry .= sprintf( '%s=%s&', $var, $val );
		}
 
	}
 
	return '?' . rtrim( $finalQry, '&' );
 
}

Any variables you supply will overwrite variables from the current query string.

Examples

<a href="<?= mergeQuery( 'page=1&id=23' ) ?>">
<a href="otherpage.php<?= mergeQuery( "page=5&id={$data['id']}" ) ?>">

Maybe someone else will find some use for it

Jun01

Returning an instance of a class from PDO

You can have PDO create and return an object(s) of a specific class. It can be a little tricky getting it to work though…

With fetchAll() you can pass ( PDO:FETCH_CLASS, ‘class_name’ ) directly

$sql = sprintf( 'select * from %s where prod_id=:prod_id', TABLE );
$findProducts = $this->db->prepare( $sql );
$findProduct->execute();
$products = $findProducts->fetchAll( PDO::FETCH_CLASS, 'Product' );

But with fetch() you must initiate it with setFetchMode

$sql = sprintf( 'select * from %s where prod_id=:prod_id', TABLE );
$findProduct = $this->db->prepare( $sql );
$findProduct->setFetchMode( PDO::FETCH_CLASS, 'Product' );
$findProduct->execute();
$product = $findProduct->fetch( PDO::FETCH_CLASS );
May12

Setting mysql connection charset with PDO

Recently while creating a store locator for a Chinese company I ran into a problem. Some Chinese characters were being displayed correctly and some weren’t. First thing I did was check the charset of the HTTP headers and the database… both were set correctly to utf-8. I figured it had to be a database issue so I began googling and found this.

Apparently you have to set the character set of the connection as well via:

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SET NAMES 'utf-8'
SET NAMES indicates what character set the client will use to send SQL statements to the server. Thus, SET NAMES ‘cp1251′ tells the server “future incoming messages from this client are in character set cp1251.” It also specifies the character set that the server should use for sending results back to the client. (For example, it indicates what character set to use for column values if you use a SELECT statement.)

Great!

The only issue remaining was the fact that I didn’t want to have to run that query on every page.

I use PDO, and I found out you can use the driver_options argument of PDO to run an initial command.

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$dsn = sprintf( 'mysql:dbname=%s;host=%s', DB_NAME, DB_HOST );
$driver_options = array( PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES utf-8' );
try {
    $dbc = new pdo($dsn, $user, $pw, $driver_options);
}
catch (PDOException $e) {
    // Handle exception
}

Good reads about character sets