BF on CF
Adobe ColdFusion 8 Tips
A compilation of Ben Forta's blog entries from his ColdFusion 8 user group tour
Jun. 13, 2007 06:00 PM
To debug your code you can do the following:
- Open the ColdFusion file to be debugged in Eclipse.
- Set breakpoints as needed by double-clicking to the left of the desired line in the vertical bar to the left of the Eclipse editor window. You'll see a little circle appear, indicating that a breakpoint has been set. You can also right-click in the vertical bar and select "Toggle Breakpoint".
- Now you need to switch to the Eclipse Debug view (called a "Perspective" in Eclipse). If you see a Debug button listed with the Perspectives on the top right of Eclipse, click it. Or, just click the Open Perspective button (or select Windows->Open Perspective) and select "Debug".
- Once you are in the Debug perspective, start the debugging session. To do this, go back to the dialog where you defined the ColdFusion server (under the Debug button), select the ColdFusion server to debug against, and click the Debug button at the bottom of the dialog.
- Eclipse will pause while it opens a debug session, connecting to the specified ColdFusion server. You'll see the connection show up in the Debug window.
- Now just open any browser and run your application. When you request a page with a breakpoint, execution will pause and the debugger will pop up. You'll be able to step through the code, view variables and expressions (in the top right panel), see generated server output, and more.
- When you're done debugging, you can terminate the debug session by clicking the red square Terminate button.
That'll do it. I know this seems complex and a lot of work, but the bulk of it is the initial setup. Once that setup is complete, you'll be able to quickly and easily fire up the debugger on demand and when needed.
ColdFusion 8 File I/O Enhancements
At one of the usergroup sessions someone asked if there was a way to get file information (size, date time, etc.) easily using a function. I said they should use <CFDIRECTORY>, but afterwards remembered that we did indeed add a new function to ColdFusion 8 called GetFileInfo() that returns a structure containing:
- canread
- canwrite
- ishidden
- lastmodified
- name
- parent
- path
- size
- type
Which makes this a good opportunity to review some of the file i/o changes coming in ColdFusion 8.
For starters, if you ever had to work with large text files in ColdFusion (maybe parsing a large CSV file), you'll know that doing so is very inefficient. You probably use code like this:
<!--- Read entire file --->
<cffile action="read"
file="#fileName#"
variable="myFile">
<!--- Loop through file variable one line at a time --->
<cfloop list="#myFile#"
index="line"
delimiters="#chr(10)##chr(13)#">
<!--- Do stuff with line here --->
...
</cfloop>
This is slow for two reasons. Not only does ColdFusion read the entire file into memory in a variable all at once, but also looping through the file requires treating it as a list, which involves lots of parsing that can also be resource intensive.
Well, inefficient no more. In ColdFusion ColdFusion 8 you'll be able to replace the above code block with this:
<!--- Loop through file one line at a time --->
<cfloop file="#fileName#" index="line">
<!--- Do stuff with line here --->
...
</cfloop>
This code block opens the file, reads one line at a time, and closes it when done. I actually used this myself recently in a ColdFusion code snippet that had to parse a massive tab-delimited file, turning each line into a query row. Replacing the old <CFFILE> <CFLOOP> with a new <CFFILE FILE=> cut down the processing time from several minutes to under 10 seconds.
Although reading files line by line is the more common use case, you can also read by n characters at a time, like this:
<!--- Loop through file 100 characters at a time --->
<cfloop file="#fileName#" index="chars" characters="100">
<!--- Do stuff with line here --->
...
</cfloop>
About Ben FortaBen Forta is Adobe's evangelist for the ColdFusion product line. He is the author of several books.