Here’s another “for later reference”…

Microsoft’s rules for .NET Framework 1.1 Abbreviations consist of:

• Do not use abbreviations or contractions as parts of identifier names. For example, use GetWindow instead of GetWin.
• Do not use acronyms that are not generally accepted in the computing field.
• Where appropriate, use well-known acronyms to replace lengthy phrase names. For example, use UI for User Interface and OLAP for On-line Analytical Processing.
• When using acronyms, use Pascal case or camel case for acronyms more than two characters long. For example, use HtmlButton or htmlButton. However, you should capitalize acronyms that consist of only two characters, such as System.IO instead of System.Io.
• Do not use abbreviations in identifiers or parameter names. If you must use abbreviations, use camel case for abbreviations that consist of more than two characters, even if this contradicts the standard abbreviation of the word.

These appear to be good guidelines to follow for ColdFusion as well. I was going after casing for two letter acronyms in this case.

REF: http://msdn.microsoft.com/en-us/library/141e06ef(v=vs.71).aspx

Consider the following code:

a = b = c = 1000000;
r = (a > 10000) ? a/1000 : a & "/" & (b > 10000) ? b/1000 : b & "/" & (c > 10000) ? c/1000 : c;

(if you think the first line is odd – see Chaining ColdFusion Assignment Operators)

My thought was r would return “1000/1000/1000” — however it actually returned “1000”. Where did I go wrong?

Now if I change a,b,c to 1000 it would blow up to a “cannot convert the value “1000/NO” to a boolean” error.

So what’s going on? The third argument of the statement becomes another ternary statement but can not convert the evaluated “1000/NO” to a Boolean – thus blowing up. If a,b,c = 1000000 then the operation never gets to the third argument and returns only “1000” never considering the ampersand in its logic.

So correct code would be:

a = b = c = 1000000;
r = (a > 10000 ? a/1000 : a) & "/" & (b > 10000 ? b/1000 : b) & "/" & (c > 10000 ? c/1000 : c);

Or depending upon your preference:

a = b = c = 1000000;
r = ((a > 10000) ? a/1000 : a) & "/" & (b > 10000) ? b/1000 : b) & "/" & (c > 10000) ? c/1000 : c));

Now there are three seperate ternary statements concatenated together with a slash between them.

I ran into an issue where using CFContent to serve a file with spaces in its name was truncating the file name. For example the file “Foo Bar.xls” was saving as “Foo”, lacking ” Bar.xls”.

<cfheader name="Content-Disposition" value="attachment; filename=#getFileFromPath(filePath)#">
<cfcontent file="#filePath#" type="application/octet-stream">

You can find many examples of this type of code out there for securing files using ColdFusion and its cfcontent, so apparently it’s a common oversight.

The fix to truncated file names is very simple but no so obvious.

What doesn’t work:

1. Don’t wrap the file name value in anything
2. Wrapping the file name value in single quotes
3. Wrapping the file name value in double quotes

What does work:

1. Wrap the file name value in escaped quotes (doubled up such as “”#filename#””)
2. Wrap the file name value in character valued double quotes (chr(34))

The new example would look something like this:

<cfheader name="Content-Disposition" value="attachment; filename=""#getFileFromPath(filePath)#""">
<cfcontent file="#filePath#" type="application/octet-stream">

Thanks to Ben Nadel for providing this solution.

See my previous blog on serving files with CFContent at https://christierney.com/2009/08/12/securely-serving-files-via-cfcontent/ .

Thanks to Mike Henke, I found out you can chain assignment operators (“=”) in ColdFusion.

An example of this would be:

var1 = var2 = var3 = 123;

Resulting in:

var1 = 123
var2 = 123
var3 = 123

Behind the scenes it’s interpreted such as var1 = (var2 = (var3 = 123));
(It is right-associative, being the last assignment operation is evaluated first and propagated leftward. Also, don’t try that interpreted code in CF because it will fail.)

While not a major find in programming history, this little flick of keystrokes can save you some repetitive typing should you ever need to set multiple variables to the same value.

I program scripts to read XML posts just every once-and-awhile, and although very simple, every-time I forget how to do it.

Let’s say that we receive a XML HTTP POST via this code:

<cfhttp url="http://yourdomain.com/xml.cfm" method="post">
<cfhttpparam type="XML" name="MyXML" value="#myxml#">
</cfhttp>

This is what you would use to read that POST:

<cfset xmlPOST = GetHTTPRequestData().content>
<cfset xmlDOM = XmlParse(xmlPOST)>

The key here is the GetHTTPRequestData().content. Notice how we do not use form.MyXML.

Now we can manipulate the XML data using standard dot notation such as xmlDOM.Content.Value.XMLText.