Archive for category ColdFusion
Follow up to Real Time Command Execution Feedback Post
Posted by Brian in ColdFusion, Programming on April 9th, 2008
With ColdFuison 8.0.1 Adobe has introduced errorVariable and/or errorFile to the attributes of the tag. You can only use one of the two in the same tag.
This will give some insight once the tag has completed execution if there is an error. Before there was no way for CF to report errors to a file or to the browser.
ColdFusion Preserve POST variable name case
Posted by Eric in ColdFusion, Programming on April 1st, 2008
ColdFusion provides access to POSTed data via the FORM structure. Unfortunately ColdFusion always upper-cases the names of these variables. Recently a chunk of code I was working on needed to know the original case of these keys. At first I worked on passing a hidden form field with the original field name text, but this bothered me as way too much of a work-around.
This chunk of code will give you a structure called FormContent where the case of the field names is preserved.
Unfortunately this code will not distinguish between two fields with the same name but different case. To do that, you’ll want to use a case-sensitive StructNew() alternative. I recommend CreateObject(”java”, “java.util.LinkedHashMap”).init(). This has the added value of preserving the order that the fields appeared in the calling form when you iterate over it for output. It has the disadvantage that you’ll have to properly match case of the keys when you retrieve them in your code.
ColdFusion REMatchAll
Posted by Eric in ColdFusion, Programming on April 1st, 2008
This ColdFusion method offers functionality similar to PHP’s preg_match_all function. It searches for the supplied regular expression in the supplied text. The return value is an array with one entry for each time the pattern matches the string. The array entries are structs with a numbered element for each parenthesized sub-expression within the match, and a zero-entry for the whole match.
It’s probably easier to see example data.
As you can see, it returns every match, position, and full text of the match, as well as each parenthesized subexpression. The example pattern basically matches {foo|bar|baz}, {foo|bar}, or {foo}, and returns the alphabetical sub-components as the sub-expressions.
Here is the code.
Real Time Command Execution Feedback
Posted by Eric in ColdFusion, Programming on March 27th, 2008
Did you ever write a utility ColdFusion script which uses <cfexecute> to run a command and send output back to the browser? It makes for convenient and monitorable remote execution of certain repetitive tasks. My most common use for this sort of thing is for example an rsync process which can be invoked from anywhere in the world, and most recently I’ve been working with Selenium-RC to set up regression test scenarios which can be initiated by business users and business analysts without having to have Selenium IDE installed or know how to use it.
I’ve always found it frustrating though when the task is long-running, and potentially error-prone to not know the success or failure, until the entire command has been executed, and even more frustrating not knowing if it has hung up for some reason today, or does it just have a lot more work to do today than normal?
This little snippet will use Java runtime to capture and pipe the output of the program back to the browser in real time. There’s a couple of caveats surrounding needing to not be used inside a forced-buffer area (like <cfsavecontent>), but otherwise this should work just fine. That means you can’t really use it inside most modern CF frameworks which depend heavily on <cfsavecontent> and the like.
Standard input (stdin) is shut down right at the start of execution; if you wanted to interact with the program in some way (such as to script some responses to prompts), you could undo that and write to it. Standard output (stdout) and standard error (stderr) are sent to the browser and flushed in nearly real time (stderr outputs in red to boot). I use a non-busy sleep via a Java thread to check in on the running program once a second for new output. Return value is a structure containing the elements exitValue, stdOut, and stdErr, so you can do further processing with it after the fact.
Anyway, enough blather, here is the code. This is not hyper-efficient (too many string concatenations and HTMLEditFormats), so I don’t recommend you use it in any high volume situations, especially if there’s a lot of output expected from your command, but it’s been sufficient for my needs.
Example usage:
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