mysiteonline™

I was working on my Reference Statistics Tracker for work, and ran in to a snag.

I am using eZ Components' ezGraph class to create image-based graphs on the fly. It's fast, efficient, and it looks nice - it can even render in SVG (I'll be using JPG or PNG...thanks IE). For my particular needs, I wanted the exported dataset to have a specific formatting to the keys, to represent the different values in my graphs. For instance, let's say I have the following stats from 100 users in our company, and the Operating System they use. This is purely fictitious:

array('Windows' => 90, 'OSX' => 6, 'Other' => 4);

That specific array is crafted perfectly in the format that works well with eZ Components' Graphing class, for a simple bar chart, or a pie chart.

So now I just had to pull the values from the database in the format I wanted. Well my keys in this case were dates, or times (span of days, or hours in a day, or month in a year, etc...). The values were still numeric values in this case. So, we're looking at something like:

array('HH:MM:SS' => 10);

However, no matter how hard I tried, if there were no values inserted in to the database for a specific time, I could not return a value of null, or zero - even with an outer join. My next thought was to use something like array_merge() on the resulting dataset to fix it.

The PHP function of range() just didn't cut it. Although I could have converted the datetime values to timestamp values (either via SQL or PHP), and used the 3rd parameter of the function to add the specific number of seconds needed, I was weary of doing that as I remember reading about issues that could cause (adding seconds to a timestamp value calculate future time). Besides, I'd still have to use array_walk() or array_map() to format my array's keys the way I wanted; that left yet another function, and a line of code for the call to array_walk/map. (My host does not yet have PHP 5.3.x, which will allow for lambda functions in array_map.) So, I decided to create my own little function, and figured I'd post it here in case (1)someone could use it and it'd help them out, or (2)someone thinks there's a more efficient way of doing this and wants to give feedback.


<?php //$datetime_start - expects a strtotime compatible value //$datetime_end - expects a strtotime compatible value //$interval - can take either a strtotime compatible modifier (i.e.: -1 day), or an integer, // which will be perceived as total seconds and converted to a strtotime compatible modifier //$format - the format of the key for the array's key/value pair (see php.net/date for formatting options) //$value - the default value to be set for the blank array which will be used in a followup array_merge call. function datetime_range($datetime_start, $datetime_stop, $interval, $format, $value = 0){ if(is_int($interval)){ $interval = $interval . ' seconds'; } $range = array(); $datetime_start = strtotime($datetime_start); $datetime_stop = strtotime($datetime_stop); for($curTime = $datetime_start; $curTime <= $datetime_stop; $curTime = strtotime(date('r', $curTime) . ' + '.$interval)){ $range[date($format, $curTime)] = $value; } return $range; } //TIME FOR AN EXAMPLE OF USAGE: $myArray = array('10/01' =>3, '10/04' => 7, '10/05' => 4); $default = datetime_range('2009-10-01 00:00:00', '2009-10-05 00:00:00', '1 day', 'm/d'); $myArray = array_merge($default, $myArray); print_r($myArray); /************ this would have printed ************ Array( [10/01] => 3 [10/02] => 0 [10/03] => 0 [10/04] => 7 [10/05] => 4 ) ********************************************/ ?>
This could be useful for similar graphing/charting code, I don't think it's specific to eZ Components'. Perhaps it could be useful for something else that I can't think of. Have fun with it.