Web Development

Each browser has quirks for redirecting. Wikipedia has a quick reference of HTTP status codes. Today I was looking for a code that would instruct browsers to repost data to the new URL. It was much trickier than I thought.

Browsers implement both 302 and 303 to mean to go to the new URL including the get query string. 307 instructs the browser to repost any post data to the new URL including the get query string. Here is what I found on Windows.

IE6 and IE7

IE properly and silently reposts as you would expect.

Firefox 2/3

Firefox asks the user to click OK to execute the repost or CANCEL to do nothing. Doing nothing might mean that the page loads up blank, which is kind of silly.

Opera 9.25

Opera is similar to Firefox but provides a third option. Opera prompts with YES to repost, NO to use get only, and CANCEL to do nothing.

Safari 3

Safari treats a 307 the same as a 303 and gives no option to repost. Technical tests from the phaq blog.

My solution

My solution was to use 307 for IE and use HTML and JavaScript for the other browsers. I made a form full of hidden fields for each posted value and then submitted the form through JavaScript. To users, the redirect looks as you would expect.

The trick was that I could not use document.forms[0].submit() because sometimes one of the hidden elements is named submit. So I had to use an additional button that was positioned with top: -100px; in the style attribute.

For those with JavaScript disabled, I used noscript tags to enclose a notice that the page was moved and a button to go to the new location.

Demos + Source

Partial solution which always does a 307 but falls back to JavaScript when user cancels (Does not work in Safari 3, does not work when user chooses NO in Opera 9.25.)

Final solution which does a 307 for IE but uses JavaScript for other browsers

Thoughts

I was surprised to see different behavior in every browser. I don't see the advantage of the prompt other than a possible security exploit. This is an instance where IE got it exactly to spec!

Interesting article on the perfect interview question.

Here is the conclusion:

When reviewing somebody else's code, what is it that you usually find most disturbing?

An answer about syntax is a bad sign, and an answer about design principles is a good sign.

Definitely worth a try!

Here are some other questions I've heard in interviews that are useful to discern personality, experience and intelligence:

• What are you looking for in this job that you don't have in your current job?
• What interests you about this field and language of programming more than other fields and languages?
• Tell me about the something that was very difficult for you to learn and why.
• Do you consider yourself more of a fast programmer or more of a meticulous programmer?
• On a scale of 1-10, how would you rate your interest in this position? One being "no thanks" and ten being "this is my dream job!"
• What kind of work do you see yourself doing 5-7 years from now?
• Which is better: client-side validation or server-side validation?
• If you were to start an application from scratch, what code frameworks or approaches would you use and why?

I've got my old version of CompiledTemplate online in a Pastie. It's got the source and a simple example. I need to finish my new version and do some benchmarking.

It actually isn't often useful since it is usually better to generate content on the server side.