Best Practices: working with long, multiline strings in PHP?

Question

You should use heredoc or nowdoc.

$var = "some text";
$text = <<<EOT
  Place your text between the EOT. It's
  the delimiter that ends the text
  of your multiline string.
  $var
EOT;

The difference between heredoc and nowdoc is that PHP code embedded in a heredoc gets executed, while PHP code in nowdoc will be printed out as is.

$var = "foo";
$text = <<<'EOT'
  My $var
EOT;

In this case $text will have the value "My $var", not "My foo".

Notes:

• Before the closing EOT; there should be no spaces or tabs. otherwise you will get an error.
• The string/tag (EOT) that enclose the text is arbitrary, that is, one can use other strings, e.g. <<<FOO and FOO;
• EOT : End of transmission, EOD: End of data. ^[Q]

I use similar system as pix0r and I think that makes the code quite readable. Sometimes I would actually go as far as separating the line breaks in double quotes and use single quotes for the rest of the string. That way they stand out from the rest of the text and variables also stand out better if you use concatenation rather than inject them inside double quoted string. So I might do something like this with your original example:

$text = 'Hello ' . $vars->name . ','
      . "\r\n\r\n"
      . 'The second line starts two lines below.'
      . "\r\n\r\n"
      . 'I also don\'t want any spaces before the new line,'
      . ' so it\'s butted up against the left side of the screen.';

return $text;

Regarding the line breaks, with email you should always use \r\n. PHP_EOL is for files that are meant to be used in the same operating system that php is running on.

I use templates for long text:

email-template.txt contains

hello {name}!
how are you? 

In PHP I do this:

$email = file_get_contents('email-template.txt');
$email = str_replace('{name},', 'Simon', $email);

Adding \n and/or \r in the middle of the string, and having a very long line of code, like in second example, doesn't feel right : when you read the code, you don't see the result, and you have to scroll.

In this kind of situations, I always use Heredoc (Or Nowdoc, if using PHP >= 5.3) : easy to write, easy to read, no need for super-long lines, ...

For instance :

$var = 'World';
$str = <<<MARKER
this is a very
long string that
doesn't require
horizontal scrolling, 
and interpolates variables :
Hello, $var!
MARKER;

Just one thing : the end marker (and the ';' after it) must be the only thing on its line : no space/tab before or after !