Why does this if statement have each of its conditionals wrapped in PHP tags?
<?php if(!is_null($sel_subject)) { //subject selected? ?>
<h2><?php echo $sel_subject["menu_name"]; ?></h2>
<?php } elseif (!is_null($sel_page)) { //page selected? ?>
<h2><?php echo $sel_page["menu_name"]; ?></h2>
<?php } else { // nothing selected ?>
<h2>Select a subject or a page to edit</h2>
<?php } ?>
Because there is html used. Jumping between PHP and HTML is called escaping.
But I recommend you not to use PHP and HTML like this. May have a look to some template-systems e.g. Smarty or Frameworks with build-in template-systems like e.g. Symfony using twig.
Sometimes its ok if you have a file with much HTML and need to pass a PHP variable.
Sample
<?php $title="sample"; ?>
<html>
<title><?php echo $title; ?></title>
<body>
</body>
</html>
This is not much html but a sample how it could look like.
That sample you provided us should more look like....
<?php
if(!is_null($sel_subject))
{ //subject selected?
$content = $sel_subject["menu_name"];
}
else if (!is_null($sel_page))
{ //page selected?
$content = $sel_page["menu_name"];
}
else
{ // nothing selected
$content = "Select a subject or a page to edit";
}
echo "<h2>{$content}</h2>";
?>
You could echo each line of course. I prefer to store this in a variable so I can easy prevent the output by editing one line in the end and not each line where I have added a echo.
According to some comments i did a approvement to the source :)
Because the <h2> tags are not PHP and will display an error if the PHP Tags are removed.
This code will display one line of text wrapped in <h2> tags.
This is called escaping.
Because you cannot just type html between your php tags.
However, I would rather use the following syntax because it is easier to read. But that depends on the programmers opinion.
<?php
if(!is_null($sel_subject))
{ //subject selected?
echo "<h2>" . $sel_subject["menu_name"] . "</h2>";
}
elseif (!is_null($sel_page))
{ //page selected?
ehco "<h2>" . $sel_page["menu_name"] . "</h2>";
}
else
{ // nothing selected
echo "<h2>Select a subject or a page to edit</h2>";
}
Because inside the if-statement there is an HTML code, which you can put it by closing PHP tags and open it again like this:
<?php if(/*condition*/){ ?> <html></html> <?php } ?>
or:
<?php if(/*condition*/){ echo '<html></html>' ; }
That is because in this snippet we see html and php code. The code <?php changes from html-mode to php-mode and the code ?> changes back to html-mode.
There are several possibilites to rewrite this code to make it more readable. I'd suggest the following:
<?php
//subject selected?
if (!is_null($sel_subject)) {
echo "<h2>" . $sel_subject["menu_name"] . "</h2>";
//page selected?
} elseif (!is_null($sel_page)) {
echo "<h2>" . $sel_page["menu_name"] . "</h2>";
// nothing selected
} else {
echo "<h2>Select a subject or a page to edit</h2>";
}
?>
using the echo-command to output html, you don't need to change from php-mode to html-mode and you can reduce the php-tag down to only one.