Ever needed to parse a qualified URI to examine a URL for
specific information? I'm working on some code that needs
to examine links in a document and extract information about
the links.
However, those core portions are still pretty broad. The authority
can include user info, domain and port information. The path
can include embedded parameters inside each segment. So, I took
the core regular expression to break up a URI and then I do
further parsing on the authority and path
portions of the URI.
What I ended up with was a ColdFusion function that would return the following:
authority: the authority section of the Uri
directory: the directory path in the Uri (w/out parameters)
domain: the domain of the Uri
file: the file name in the Uri
fragment: the fragment of the uri (i.e. #namedAnchor)
params.url: the query string params as a struct
params.segment: the segment parameters as a struct (i.e. ;JSESSIONID=1234)
password: the password supplied in the Uri
path: the full Uri path--includes embedded parameters (i.e. ;JSESSIONID=1234)
port: the port defined in the Uri
query: the query string
scheme: the scheme/protocol (i.e. http, https, ftp, etc.)
username: the username in the Uri
I definitely know there are times when I've needed to parse information
from the current URL (i.e. to figure out if the user is using HTTP or
HTTPS.) Hopefully some of you will find this function useful.
<cfscript>
/**
* Parses a uri and returns a structure with the information in the uri
*
* @param sUrl The url to parse
* @return Returns a struct.
* @author Dan G. Switzer, II
* @version 1, September 26, 2006
*/
function parseUrl(sUrl){
// var to hold the final structure
var stUrlInfo = structNew();
// var to hold the final structure
var sCharSet = getEncoding("url");
// vars for use in the loop, so we don't have to evaluate lists and arrays more than once
var i = 1;
var sKeyPair = "";
var sKey = "";
var sValue = "";
var aQSPairs = "";
var sPath = "";
/*
from: http://www.ietf.org/rfc/rfc2396.txt
^((([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*)))?
123 4 5 6 7 8 9 A
scheme = $3
authority = $5
path = $6
query = $8
fragment = $10 (A)
*/
var sUriRegEx = "^(([^:/?##]+):)?(//([^/?##]*))?([^?##]*)(\?([^##]*))?(##(.*))?";
/*
separates the authority into user info, domain and port
^((([^@:]+)(:([^@]+))?@)?([^:]*)?(:(.*)))?
123 4 5 6 7 8
username = $3
password = $5
domain = $6
port = $8
*/
var sAuthRegEx = "^(([^@:]+)(:([^@]+))?@)?([^:]*)?(:(.*))?";
/*
separates the path into segments & parameters
((/?[^;/]+)(;([^/]+))?)
12 3 4
segment = $1
path = $2
parameters = $4
*/
var sSegRegEx = "(/?[^;/]+)(;([^/]+))?";
// parse the url looking for info
var stUriInfo = reFindNoCase(sUriRegEx, sUrl, 1, true);
// this is for the authority section
var stAuthInfo = "";
// this is for the segments in the path
var stSegInfo = "";
// if the charset argument exists, use it -- this defaults to the url encoding to mimic the default
// behavior
if( arrayLen(arguments) gte 2 ) sCharSet = arguments[2];
// create empty keys
stUrlInfo["scheme"] = "";
stUrlInfo["authority"] = "";
stUrlInfo["path"] = "";
stUrlInfo["directory"] = "";
stUrlInfo["file"] = "";
stUrlInfo["query"] = "";
stUrlInfo["fragment"] = "";
stUrlInfo["domain"] = "";
stUrlInfo["port"] = "";
stUrlInfo["username"] = "";
stUrlInfo["password"] = "";
stUrlInfo["params"] = structNew();
// get the scheme
if( stUriInfo.len[3] gt 0 ) stUrlInfo["scheme"] = mid(sUrl, stUriInfo.pos[3], stUriInfo.len[3]);
// get the authority
if( stUriInfo.len[5] gt 0 ) stUrlInfo["authority"] = mid(sUrl, stUriInfo.pos[5], stUriInfo.len[5]);
// get the path
if( stUriInfo.len[6] gt 0 ) stUrlInfo["path"] = mid(sUrl, stUriInfo.pos[6], stUriInfo.len[6]);
// get the path
if( stUriInfo.len[8] gt 0 ) stUrlInfo["query"] = mid(sUrl, stUriInfo.pos[8], stUriInfo.len[8]);
// get the fragment
if( stUriInfo.len[10] gt 0 ) stUrlInfo["fragment"] = mid(sUrl, stUriInfo.pos[10], stUriInfo.len[10]);
// break authority into user info, domain and ports
if( len(stUrlInfo["authority"]) gt 0 ){
// parse the authority looking for info
stAuthInfo = reFindNoCase(sAuthRegEx, stUrlInfo["authority"], 1, true);
// get the domain
if( stAuthInfo.len[6] gt 0 ) stUrlInfo["domain"] = mid(stUrlInfo["authority"], stAuthInfo.pos[6], stAuthInfo.len[6]);
// get the port
if( stAuthInfo.len[8] gt 0 ) stUrlInfo["port"] = mid(stUrlInfo["authority"], stAuthInfo.pos[8], stAuthInfo.len[8]);
// get the username
if( stAuthInfo.len[3] gt 0 ) stUrlInfo["username"] = mid(stUrlInfo["authority"], stAuthInfo.pos[3], stAuthInfo.len[3]);
// get the password
if( stAuthInfo.len[5] gt 0 ) stUrlInfo["password"] = mid(stUrlInfo["authority"], stAuthInfo.pos[5], stAuthInfo.len[5]);
}
// the query string in struct form
stUrlInfo["params"]["segment"] = structNew();
// if the path contains any parameters, we need to parse them out
if( find(";", stUrlInfo["path"]) gt 0 ){
// this is for the segments in the path
stSegInfo = reFindNoCase(sSegRegEx, stUrlInfo["path"], 1, true);
// loop through all the segments and build the strings
while( stSegInfo.pos[1] gt 0 ){
// build the path, excluding parameters
sPath = sPath & mid(stUrlInfo["path"], stSegInfo.pos[2], stSegInfo.len[2]);
// if there are some parameters in this segment, add them to the struct
if( stSegInfo.len[4] gt 0 ){
// put the parameters into an array for easier looping
aQSPairs = listToArray(mid(stUrlInfo["path"], stSegInfo.pos[4], stSegInfo.len[4]), ";");
// now, loop over the array and build the struct
for( i=1; i lte arrayLen(aQSPairs); i=i+1 ){
sKeyPair = aQSPairs[i]; // current pair
sKey = listFirst(sKeyPair, "="); // current key
// make sure there are 2 keys
if( listLen(sKeyPair, "=") gt 1){
sValue = listLast(sKeyPair, "="); // current value
// fix bug in urlDecode w/single % signs
sValue = reReplaceNoCase(sValue, "%([^A-F0-9{2}])", "%25\1", "all");
// url decode the value
sValue = urlDecode(sValue, sCharSet);
} else {
sValue = ""; // set blank value
}
// check if key already added to struct
if( structKeyExists(stUrlInfo["params"]["segment"], sKey) ) stUrlInfo["params"]["segment"][sKey] = listAppend(stUrlInfo["params"]["segment"][sKey], sValue); // add value to list
else structInsert(stUrlInfo["params"]["segment"], sKey, sValue); // add new key/value pair
}
}
// get the ending position
i = stSegInfo.pos[1] + stSegInfo.len[1];
// get the next segment
stSegInfo = reFindNoCase(sSegRegEx, stUrlInfo["path"], i, true);
}
} else {
// set the current path
sPath = stUrlInfo["path"];
}
// get the file name
stUrlInfo["file"] = getFileFromPath(sPath);
// get the directory path by removing the file name
if( len(stUrlInfo["file"]) gt 0 ){
stUrlInfo["directory"] = replace(sPath, stUrlInfo["file"], "", "one");
} else {
stUrlInfo["directory"] = sPath;
}
// the query string in struct form
stUrlInfo["params"]["url"] = structNew();
// if query info was supplied, break it into a struct
if( len(stUrlInfo["query"]) gt 0 ){
// put the query string into an array for easier looping
aQSPairs = listToArray(stUrlInfo["query"], "&");
// now, loop over the array and build the struct
for( i=1; i lte arrayLen(aQSPairs); i=i+1 ){
sKeyPair = aQSPairs[i]; // current pair
sKey = listFirst(sKeyPair, "="); // current key
// make sure there are 2 keys
if( listLen(sKeyPair, "=") gt 1){
sValue = urlDecode(listLast(sKeyPair, "=")); // current value
} else {
sValue = ""; // set blank value
}
// check if key already added to struct
if( structKeyExists(stUrlInfo["params"]["url"], sKey) ) stUrlInfo["params"]["url"][sKey] = listAppend(stUrlInfo["params"]["url"][sKey], sValue); // add value to list
else structInsert(stUrlInfo["params"]["url"], sKey, sValue); // add new key/value pair
}
}
// return the struct
return stUrlInfo;
}
</cfscript>
NOTE:
UPDATE 2006-09-27:
Updated the code to allow for custom charsets for the urlDecode() function. I found
that when using the urlDecode() method on data coming from the database or xml
document, it may have encoding different than the URL scope. By default CFMX
uses the URL encoding for the urlDecode() format.
The example below shows how the URI would get broken down:
Example
http://usr:pwd@www.foo.com:80/bar/sub/file.gif;p=5?q1=item1&q1=item2&q2=item3#nameAnchor
authority usr:pwd@www.foo.com:80
directory /bar/sub/
domain www.foo.com
file file.gif
fragment nameAnchor
params [struct]
segment [struct]
p: 5
url [struct]
q1: item1,item2
q2: item3
password: pwd
path: /bar/sub/file.gif;p=5
port: 80
query: q1=item1&q1=item2&q2=item3
scheme: http
username: usr
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