Thought Delimited

I've made some updates to my dirtyFields jQuery plugin.  Here's the rundown:

• Added two new public functions:
  • getDirtyFieldNames() returns an array of all currently dirty fields.
  • updateFormState() checks the clean/dirty state of all form fields in the specified container
• Made two changes to how the CSS class denoting a dirty/changed form is applied:
  • Added a new configuration option ("self") to apply the class to the actual form element.
  • Split the single option for applying a style to a changed text input and select drop-down into two separate options for granular control (if you used the textboxSelectContext option with a previous version of the plugin, you will need to update your code).
• Added three new configuration options to control plugin behavior:
  • The denoteDirtyFields option controls whether or not the dirty CSS class is applied to the form elements that are dirty/changed.
  • The exclusionClass option specifies the name of the CSS class that, when applied to a form field, will exclude that field from being processed by the plugin.
  • The ignoreCaseClass option specifies the name of the CSS class that, when applied to a form field, will instruct the plugin to do a case-insensitive evaluation of the current and original states of the field.

All of these changes were implemented in response to code suggestions made a team of developers (listed in the GitHub readme.txt file) who modified the plugin to meet their specific needs in one of their intranet sites.

Today I had the need to write code that would loop over a recordset, parse the data in each iteration, and then insert the transformed data into another table.  Nothing I haven't done countless times, but this time I was using the query functions in cfscript to do my inserts.  I knew the resulting code was going to be a bit slow (as inserting thousands of rows takes time), but when I ran it it was a LOT slower than I expected.

After adding some code to time the various parts of my routine, I discovered that the time it took for each insert transaction was steadily growing with each iteration of the loop, to the point where it was taking 500+ milliseconds per insert.  But why?

Then I saw the problem.  I had forgotten to invoke the query object's clearParams() function at either the beginning or end of my loop.  Apparently ColdFusion will let you create a query parameter with the same name attribute using addParam() - as was happening in my loop - and not throw an error (which is what I would have expected to happen), but it leads to a performance issue with the SQL execution.

In the few times where I've reused a query object with different parameters, I've been careful to use clearParams(), but I simply overlooked it this time.  Lesson learned.

In addition to the normal aggregate functions (Count, Sum, Avg, etc.), most database implementations of SQL also include functions for manipulating string values.  One of those is substr(), which allows you to extract a substring of the text value in a database field by specifying the start position and the number of characters. 

So if you wanted to extract the first 5 digits of a 9-digit postal code from your "zipCode" field.  You could do it like so:

select substr(zipCode,1,5) as mainZip...

...where 1 is the starting position and 5 the number of characters.  If you knew that the format of all the zip codes was "xxxxx-xxxx", then you could also retrieve the last 4-digits by moving the starting position and adjusting the character count:

select substring(zipCode,6,4) as extendedZip...

But what if you had strings where you wanted to extract the last 4 letters in the string, but the string length varied, like these values:

Professor - GVPT
Assist. Professor - LTSC
Prof. Emeritus - ENGR

You could use the length() function to get the full length of the string and then subtract one less than the number of characters you want from it to get the starting position:

select substr(nameDept,length(nameDept)-3,4) as dept...

...but Oracle and MySQL provide a simpler method:  you can designate the starting position from the right end of the string by using a negative number:

select substr(nameDept,-4,4) as dept...

One of the functional requirements for the voter registration application I blogged about recently was that the application should not allow further registrations between the registration deadline (October 16 at 9pm) and a date after the election specified by the state Board of Elections.  For the initial run of the application, I simply hard-coded the deadline and restart date into the application logic, knowing full well I couldn't leave it that way unless I wanted to personally change the code year after year....which I don't.

So this week I set out to write a tool within the administrative interface of the application that would allow a non-programmer to update the deadline and restart date every year.  The jQuery UI Datepicker widget is my tool of choice when it comes to having users enter or edit a date, but I've used a few different approaches to having users enter a time of day.  This time around, I decided to see I if could find something comparable to the Datepicker widget for setting the time.

What I found was a rather sweet plugin called the Timepicker Addon that adds a set of time controls to the jQuery UI Datepicker.  If you customize your jQuery UI download to include both the Slider and Datepicker widgets, you can present the time controls as sliders, like so (without the Slider widget, you get select boxes):

The plugin comes with a number of configuration settings so you can do things like adjust the time increments, change how the time is displayed, and allow the user to denote the time zone associated with the time value.  Once I had the plugin configured the way I wanted, I simply had to write some code to validate the date and time string submitted from the form field, and I was done.  Very cool.

Recently, I had to create JavaScript-based replacements for 2 Java applets in an application I inherited.  One of the applets was a collapsible hierarchy tree of organizational units that used the conventional triangle icons (pointing right for closed, pointing down for open) to indicate state.

In past applications, I'd simply created actual triangle icons of the appropriate color for this sort of thing, but this time I decided I wanted to do it in pure CSS.

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