[FX.php List] PHP Question

[Steve Hannah]

On 20-Jul-06, at 3:51 PM, Kevin Futter wrote:

> On 21/7/06 3:25 AM, "Bob Patin" <bob at patin.com> wrote:
>
>> I don't know why I never thought to use ECHO rather than to move  
>> in and out of PHP code... !
>>
>> This is much more elegant; I'll definitely store this away for  
>> future use...
>>
>>
> That’s an interesting comment Bob. I tend to go the other way – I  
> try as hard as I can to separate data processing logic from both  
> structural and presentational layers.
I agree with you on this approach, as you are describing the MVC  
(Model-View-Controller) pattern.  Unfortunately PHP, on its own,  
doesn't cater all that well to MVC.  It works well for page layouts  
where you only have to drop a view variables into a largely HTML page:

e.g. <title><?=$mytitle?></title>
...

But as soon as you add control logic with "if" statements and loops  
you end up with a mess like:
<? if ($condition){ ?>
     <p>Some information:</p>
    <ul>
    <? foreach ($myvars as $key=>$value){ ?>
         <li><?=$key?> is <?= $value?></li>
    <? } ?>
     </ul>
<? } ?>

You can see how it would be easy to lose one of the closing braces in  
the midst of a bunch of html code.  The above example becomes:
if ( $condition){
     echo "<p>Some information</p>
	<ul>";
     foreach ($myvars as $key=>$value){
         echo "<li>$key is $value</li>";
     }
     echo "</ul>";
}

  A little bit more sightly and much easier to keep track of the  
opening and closing braces.  Of course if we start putting too much  
html in there then it could become difficult to keep track of the  
html tags and we have the same problem in the other direction.

The best way to do MVC in PHP is to use some sort of templating  
engine like smarty so that this is done in a way that is easy to  
follow and debug in  both HTML and PHP terms

e.g.
{if $condition}
     <p>Some information:</p>
     <ul>
     {foreach from=$myvars key=key item=value}
         <li>{$key} is {$value}</li>
     {/foreach}
     </ul>
{/if}

Readable in both PHP and HTML terms.

However there are further considerations when it comes to PHP.    
Sometimes you just want to display a small bit of text and this bit  
will be displayed several times - maybe as part of a loop.  You have  
to be careful that you don't reload (re-include) the template page  
every time the snippet is displayed or your performance tanks.  In  
this case I would tend to use ECHO statements over dropping out of  
PHP (e.g. ?> <p>my test</p> <? ) because when there is just a small  
amount of HTML code inside your PHP function, the readability of the  
PHP is more important than the readability of the HTML.

Anyways, that is just my take on the issue after years of trying it  
every way under the sun.

Best regards

Steve

> I’ll put all parsing logic at the top of a page, above any HTML  
> code, and try to only drop into PHP when I need to print db data or  
> other logic-based tasks. For example, if I’m not using PHP to write  
> any variables into an element on a page, then (unless I’m using a  
> loop to write out a table) I won’t use PHP to do it.
>
> For my money...
>
> <table>
> <?php
> // code to write out table rows and cells
> ?>
> </table>
>
> ...is cleaner, more elegant and easier to read than needlessly  
> getting PHP to write out HTML elements.
>
> -- 
> Kevin Futter
> Webmaster, St. Bernard's College
> http://www.sbc.melb.catholic.edu.au/
>
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