Embedding CSS file in html e-mail

Sending html e-mails opens a whole can of worms on the many ways e-mail can be viewed. There is also no guarantee your e-mail will look as intended.

Instead of linking to a remote css file that may be blocked, or prompt the user with a scary ‘prevented external content to load’ error message, we can use PHP to pull the file directly. This adheres to the DRY principle and keeps the code base clean.

Use the file_get_contents function in place of linking a style sheet via an html style element.

I would also recommend a try/catch block in case the file_get_contents command fails.

Solution

In head section:

<style type="text/css" media="screen">
	<!-- we do this to embed the file contents into the e-mail.
	<?php echo file_get_contents("../common/css/blueprint/screen.css"); ?>
	-->
</style>

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Pass object association by reference via & to save resources

Not really a big deal, but could save resources on larger arrays. Is also a clean code practice to avoid awkward traversing array and assigning to ‘itself’ from what is essentially a sub routine.

Does it really matter? Likely not. Using the below script on my 2.66 Core i7 with 8gigs of ram passing by reference is roughly 3-4 times faster. At 100000 array key value pairs the difference is still in microseconds (less than half a millisecond).

More information here: http://php.net/manual/en/language.references.pass.php

<?php

// want to loop over an array
$an_array = array();

// lets populate it with random values
for ($i=0; $i < 100000; $i++) { 
	$an_array[$i] = md5(uniqid(uniqid("",true),true));
}

// start
var_dump(microtime(true));

// now lets maniuplate the 'old' way
foreach ($an_array as $key => $value) {
	// this modifies the value at the index using the array and key
	$an_array[$key] = "ref original array and key";
}

var_dump(microtime(true));

// lets do it the 'new' way, notice we are passing &
foreach ($an_array as $key => &$value) {
	// $value is a reference to the $an_array[$key]
	$value = "changes source array";
}
// finish
var_dump(microtime(true));

?>

Sample Executions

Object	Pass reference
445	123
455	122
443	122
452	119
446	129

*Note* times in microseconds

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Get last month’s date range in PHP

I needed to get last month’s valid date range in php for running reports. A quick google search showed the top results for accomplishing this used for loops that subtracted/added days from now until casting as a date object returned false.

Needless to say, no way am I doing that. So below I have a code snippet that returns the valid start and end date of the previous month. This could be modified in a variety of ways to suit your needs. Needless to say I was disappointed that strtotime did not accept “First day of last month”.

// this returns a date string which I need, but removing the casting as a date
// returns a unix timestamp value more useful for calculations
$first_of_last_month = date('m/d/y',mktime(0,0,0,date('m')-1,1,date('y')));
$end_of_last_month = date('m/d/y',mktime(0,0,0,date('m'),0,date('y')));

// if run on 03/01/11
var_dump($first_of_last_month, $end_of_last_month);
// outputs
// string(8) "02/01/11"
// string(8) "02/28/11"

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