Form validation is an important part of Web development. It provides the user feedback when they make a mistake or omit information. And it protects the integrity of the application data.
In the past I have written 2 sets of form validation: 1 client-side and 1 server-side. Server side form validation is essential. Client-side validation wasn't always necessary in the past, but provided a better user experience. However, as more and more dynamic client-side content is being generated, it is becoming more essential and users are not as tolerant of "press the back button to correct your errors".
So instead of writing 2 sets of validation code (one in JavaScript and one in ColdFusion), I now levy the power of AJAX to only write one set of form validation code.
The way it works is to submit the form data to the server first via AJAX. The server side code then generates any and all error messages based on the form data. If there are errors, it sends the error messages back to the browser as JSON array. If there are no errors, then it submits the form to the client.
So what if the user has JavaScript disabled (does anybody do that anymore?) or somehow JavaScript is bypassed? The same error messages are then presented back to the user regardless. Here's some sample code to make more sense of it.
First our HTML form:
Next we add the JavaScript to handle the AJAX check and form submission:
And finally the client-side code:
Friday, February 17, 2012
Tuesday, February 7, 2012
Paperless Billing
One of my goals for 2012 has been to get better organized and get a better grip on my finances. And one way that I've done that is to switch to paperless billing for some of my accounts. I have tried this in the past but it never worked because I would lose the bill in my inbox. But I have come up with a solution that seems to work better this time.
The first thing I did was to download Mozilla Thunderbird onto my desktop and put it in my Startup folder. Then I created a new email called statements@my-domain-name-dot-com and configured Thunderbird to check it. Next I created a second email called bills@my-domain-name-dot-com that forwards all incoming mail to the statements account as well as the email account I check on my iPhone. That way when I get a bill, I get a reminder on my phone AND on my desktop computer at home. Lastly, I used the filtering capabilities of Thunderbird to move the various bills and statements into folders for each company I do business with.
The first thing I did was to download Mozilla Thunderbird onto my desktop and put it in my Startup folder. Then I created a new email called statements@my-domain-name-dot-com and configured Thunderbird to check it. Next I created a second email called bills@my-domain-name-dot-com that forwards all incoming mail to the statements account as well as the email account I check on my iPhone. That way when I get a bill, I get a reminder on my phone AND on my desktop computer at home. Lastly, I used the filtering capabilities of Thunderbird to move the various bills and statements into folders for each company I do business with.
