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In PHP, the HEREDOC string declarations are really useful for outputting a block of html. You can have it parse in variables just by prefixing them with $, but for more complicated syntax (like $var[2][3]), you have to put your expression inside {} braces.
In PHP 5, it is possible to actually make function calls within {} braces inside a HEREDOC string, but you have to go through a bit of work. The function name itself has to be stored in a variable, and you have to call it like it is a dynamically-named function. For example:
$fn = 'testfunction'; function testfunction() { return 'ok'; } $string = <<< heredoc plain text and now a function: {$fn()} heredoc; As you can see, this is a bit more messy than just:
$string = <<< heredoc plain text and now a function: {testfunction()} heredoc; There are other ways besides the first code example, such as breaking out of the HEREDOC to call the function, or reversing the issue and doing something like:
?> <!-- directly output html and only breaking into php for the function --> plain text and now a function: <?PHP print testfunction(); ?> The latter has the disadvantage that the output is directly put into the output stream (unless I'm using output buffering), which might not be what I want.
So, the essence of my question is: is there a more elegant way to approach this?
Edit based on responses: It certainly does seem like some kind of template engine would make my life much easier, but it would require me basically invert my usual PHP style. Not that that's a bad thing, but it explains my inertia.. I'm up for figuring out ways to make life easier though, so I'm looking into templates now.
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In PHP 5, it is possible to actually make function calls within {} braces inside a HEREDOC string, but you have to go through a bit of work. The function name itself has to be stored in a variable, and you have to call it like it is a dynamically-named function.
Heredoc PHP syntax is a way to write large bloc of text inside PHP, without the classic single quote, double quotes delimiters. It relies on <<< and a token that will also mark the end of the string.
In computing, a here document (here-document, here-text, heredoc, hereis, here-string or here-script) is a file literal or input stream literal: it is a section of a source code file that is treated as if it were a separate file.
Heredoc and Nowdoc are two methods for defining a string. A third and fourth way to delimit strings are the Heredoc and Nowdoc; Heredoc processes $variable and special character but Nowdoc does not processes a variable and special characters.
If you really want to do this but a bit simpler than using a class you can use:
function fn($data) { return $data; } $fn = 'fn'; $my_string = <<<EOT Number of seconds since the Unix Epoch: {$fn(time())} EOT; I would not use HEREDOC at all for this, personally. It just doesn't make for a good "template building" system. All your HTML is locked down in a string which has several disadvantages
Get a basic template engine, or just use PHP with includes - it's why the language has the <?php and ?> delimiters.
template_file.php
<html> <head> <title><?php echo $page_title; ?></title> </head> <body> <?php echo getPageContent(); ?> </body> index.php
<?php $page_title = "This is a simple demo"; function getPageContent() { return '<p>Hello World!</p>'; } include('template_file.php'); If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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