Category: ColdFusion

More URI-Related UDFs

To follow up my parseUri() function, here are several more UDFs I've written recently to help with URI management:

  • getPageUri()
    Returns a struct containing the relative and absolute URIs of the current page. The difference between getPageUri().relative and CGI.SCRIPT_NAME is that the former will include the query string, if present.
  • matchUri(testUri, [masterUri])
    Returns a Boolean indicating whether or not two URIs are the same, disregarding the following differences:
    • Fragments (page anchors), e.g., "#top".
    • Inclusion of "index.cfm" in paths, e.g., "/dir/" vs. "/dir/index.cfm" (supports trailing query strings).
    If masterUri is not provided, the current page is used for comparison (supports both relative and absolute URIs).
  • replaceUriQueryKey(uri, key, substring)
    Replaces a URI query key and its value with a supplied key=value pair. Works with relative and absolute URIs, as well as standalone query strings (with or without a leading "?"). This is also used to support the following two UDFs:
  • addUriQueryKey(uri, key, value)
    Removes any existing instances of the supplied key, then appends it together with the provided value to the provided URI.
  • removeUriQueryKey(uri, key)
    Removes one or more query keys (comma delimited) and their values from the provided URI.

View the source code.

Now that I have these at my disposal, I frequently find myself using them in combination with each other. E.g.:

<a href="<cfoutput>#addUriQueryKey(
	getPageUri().relative,
	"key",
	"value"
)#</cfoutput>">Link</a>.

Let me know if you find any of these useful.

In other news, this cracked me up.

parseUri: Split URLs in ColdFusion

Update: I've added a JavaScript implementation of the following UDF. See parseUri: Split URLs in JavaScript.

Here's a UDF I wrote recently which allows me to show off my regex skillz. parseUri() splits any well-formed URI into its components (all are optional).

The core code is already very brief, but I could replace everything within the <cfloop> with one line of code if I didn't have to account for bugs in the reFind() function (tested in CF7). Note that all components are split with a single regex, using backreferences. My favorite part of this UDF is its robust support for splitting the directory path and filename (it supports directories with periods, and without a trailing backslash), which I haven't seen matched in other URI parsers.

Since the function returns a struct, you can do, e.g., parseUri(uri).anchor, etc. Check it out:

See the demo and get the source code.

REMatch (ColdFusion)

Following are some UDFs I wrote recently to make using regexes in ColdFusion a bit easier. The biggest deal here is my reMatch() function.

reMatch(), in its most basic usage, is similar to JavaScript's String.prototype.match() method. Compare getting the first number in a string using reMatch() vs. built-in ColdFusion functions:

  • reMatch:
    <cfset num = reMatch("\d+", string) />
  • reReplace:
    <cfset num = reReplace(string, "\D*(\d+).*", "\1") />
  • reFind:
    <cfset match = reFind("\d+", string, 1, TRUE) />
    <cfset num = mid(string, match.pos[1], match.len[1]) />

All of the above would return the same result, unless a number wasn't found in the string, in which case the reFind()-based method would throw an error since the mid() function would be passed a start value of 0. I think it's pretty clear from the above which approach is easiest to use for a situation like this, and it would be easy to envision scenarios where this functionality could more drastically improve code brevity.

Still, that's just the beginning of what reMatch() can do. Change the scope argument from the default of "ONE" to "ALL" (to follow the convention used by reReplace(), etc.), and the function will return an array of all matches. Finally, set the returnLenPos argument to TRUE and the function will return either a struct or array of structs (based on the value of scope) containing the len, pos, AND value of each match. This is very different from how the returnSubExpressions argument of reFind() works. When using returnSubExpressions, you get back a struct containing arrays of the len and pos (but not value) of each backreference from the first match.

Here's the code, with four additional UDFs (reMatchNoCase(), match(), matchNoCase(), and reEscape()) added for good measure:

See the demo and get the source code.

Now that I've got a deeply featured match function, all I need Adobe to add to ColdFusion in the way to regex support is lookbehinds, atomic groups, possessive quantifiers, conditionals, balancing groups, etc., etc.…