pelago

UPDATED February 19th, 2010: As BobM pointed out, the original solution to this problem didn’t account for fractional decimals. Originally I didn’t include them because Intervals didn’t require that level of precision, but apparently fractional decimals are quite common elsewhere. Because of that, I’ve updated this post, along with the regex, to include support for fractional decimals.

For the Intervals API, we’re wrestling with issues surrounding data input validation. This recently became interesting when the matter of date validation came up. Ordinarily, Intervals allows many, many different date formats, dependent on the locale that the customer is using (for example, Intervals may expect the date format ‘mm/dd/yyyy’ for US customers, ‘dd.mm.yy’ for a customer in Austria).

For our API developers, we wanted to use a common, universal format, one that would be easily compatible with our application and database layers. For that we selected ISO 8601, which is great in terms of widespread use, but not so great in terms of how complicated its specifications are.

Generally, ISO 8601 looks something like ‘2009-05-20′ for dates and ‘2009-05-20 12:30:30′ for date/time combinations. These two examples encompass 98% of the user input we’re likely to encounter. But we wanted to make sure that if we told developers they could use ISO 8601 dates, our system would support it. (more…)

On one of our sites were were running into a problem when we tried to pass HTML content from a database through an email obfuscation function to prevent spiders from scraping our clients’ email addresses. We quickly discovered that some of the longer pages were showing up completely blank. The preg_replace() function we were using to run the obfuscation code on email addresses was returning null. After some hunting I found the answer.

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