UriTemplate and UriPattern for simple tokenized URI building and parsing

NEW POST: Release 1.1

IDisposable — Sat, 27 Oct 2007 01:18:49 GMT

The changes look good to me. They passed the few unit tests that I have created so far.

Thanks, released!

I have started building a URIPatternTable to be able to perform the same function that URITemplateTable does in System.ServiceModel.Web. Would you be interested in including it in the project?

Sure, make the changes and send me a zip... if they pass snuff, I'll add you as a developer on the project and you can check-in directly...

Also, if I were to build a bunch of unit tests, what test framework would be the most appropriate.

I've been hesitant to couple any of my CodePlex projects to a specific testing framework, but Brad Wilson's new xUnit is making me consider doing so.

COMMENTED ISSUE: meta characters are not replaced as intended

IDisposable — Sat, 27 Oct 2007 01:10:44 GMT

Try this test:
UriPattern p = UriPattern.Create("/LiveContacts/Contacts/Contact({ContactId})");
IDictionary<string, string> values = p.Parse("/LiveContacts/Contacts/Contact(1001)");
Assert.AreEqual<string>("1001", values["ContactId"]);

It will fail because in the UriPattern.BuildRegex the code is supposed to be doing a regex replace to escape all meta characters, but it actually just attempts a string replace, which does nothing.

The following lines fix the problem.

private static Regex regexMetaPattern = new Regex(@"[\\\[\]\&\^\$\?\#\+\*\|\>\<]", RegexOptions.Compiled); // This is a regex not a string
private static string regexMetaCharactersReplacements = @"\$0"; // Removed a slash here also

In UriTemplate.BuildRegex, change the template.Replace(...) to
template = regexMetaPattern.Replace(template,regexMetaCharactersReplacements) + ".*";

I looked at Snell's original code and the bug is there also.
Comments: ** Comment from web user: IDisposable **

To be fair, it was my mistake in translating from the java original, since in java's string class, the replaceAll method expects a regex pattern, not a raw pattern. Mea Culpa

UPDATED WIKI: Home

IDisposable — Sat, 27 Oct 2007 00:50:45 GMT

Project Description

The UriTemplate library is a simple set of code to encapsulate the building and parsing of URIs from replacement tokens. Using this couple of classes will make it easy to build RESTful URIs.

News

1.1 Release on 10/26/2007 to include a fix patterns with Regex meta-characters and ability to build compiled UriPatterns.

What the heck is this all about?

UriTemplates are a simple way to codify the build of URI strings that follow web-optimization and RESTful principles. In short, you want URIs that are "hackable" and well formed. UriTemplates allow regular constructing and parsing through named tokens that specify where logical substitutions should be performed.

The idea of a UriTemplate was probably best described by Joe Gregorio in this blog posting http://bitworking.org/news/URI_Templates and it simply talks about using URIs patterns like http://example.org/{item}/{userid} into strings like http://example.org/users/1234 and back, given a dictionary of token/value pairs where item = "users' and userid = "1234". The ability to generate well-formed URIs from the dictionary, or parse them out for incoming requests lets you easily build RESTful interfaces.

The desire to implement this came from the upcoming UriTemplate in .Net (currently somewhat released in the BizTalk Services SDK).
This specific implementation of the UriTemplate does not have all the cool features of the Microsoft version; rather it follows from a java class written by James Snell in a posting here http://www.snellspace.com/wp/?p=467. I felt his class was just perfect in the level of functionality and simplicity. This code is essentially a C# port to .Net from his java code.

I expect that in a few years, .Net developers will be broadly using the System.UriTemplate currently contained in the BizTalk SDK's Microsoft.ServiceModel.Web.dll. For those of us developers in the real world not able to deploy all these cool new pre-beta bits in production, this set of code will let you develop in either the 1.1 or 2.0 framework and establish the process now.

How to use

Here's the simplest possible example; a console mode application that shows how to play with UriPattern to extract values for the tokens and how to use UriTemplate to generate a new URI from those token values:

using System;
using System.Collections;
using System.Collections.Generic;
 
using UriTemplate;
 
namespace TestJig
{
    public class Program
    {
        static void Main(string[] args)
        {
            UriPattern p = UriPattern.Create("/{user}/{year}/{month}");
            IDictionary<string, string> values = p.Parse("/marc/2007/06?no#touch");
            foreach (KeyValuePair<string, string> item in values)
            {
                System.Console.WriteLine(item.Key.ToString() + " = " + item.Value.ToString());
            }
            IResolver resolver = new DictionaryResolver(values);
            string url =  UriTemplate.UriTemplate.Expand("http://localhost/paystub/{year}/{month}/{user}", resolver);
            System.Console.WriteLine(url);
        }
    }
}

Other blog entries

Steve Maine's UriTemplate 101 talks about the System.UriTemplate class upcoming in future .Net framework releases http://hyperthink.net/blog/2007/05/15/UriTemplate+101.aspx
Steve Maine's UriTemplate 101 talks about the System.UriTemplate class' Match method. http://hyperthink.net/blog/2007/05/16/UriTemplateMatch.aspx
Mark Nottingham's URI Templating talks about the specification of URI templating in a broader (not just Microsoft's .Net) scope http://www.mnot.net/blog/2006/10/04/uri_templating

UPDATED RELEASE: 1.1 Release (Oct 26, 2007)

Sat, 27 Oct 2007 00:49:04 GMT

Corrects problems with Regex metacharacters in pattern strings (like parenthesis). Add option to specify a UriTemplate to use the compile Regex option if it gets used a lot.

Thanks to Darrel Miller for catching and fixing the metacharacter issue.

NEW POST: Release 1.1

DarrelMiller — Fri, 26 Oct 2007 14:13:02 GMT

The changes look good to me. They passed the few unit tests that I have created so far.

I have started building a URIPatternTable to be able to perform the same function that URITemplateTable does in System.ServiceModel.Web. Would you be interested in including it in the project?

I find it ironic that the URITemplate that is in System.ServiceModel.Web is not capable of parsing the URIs from either Astoria or the Windows Live API. I guess this means that Microsoft have at least three teams working on URI parsing!

Also, if I were to build a bunch of unit tests, what test framework would be the most appropriate. I'm currently using VSTS.

UPDATED WIKI: Home

IDisposable — Fri, 26 Oct 2007 06:41:59 GMT

Project Description

The UriTemplate library is a simple set of code to encapsulate the building and parsing of URIs from replacement tokens. Using this couple of classes will make it easy to build RESTful URIs.

News

1.1 Release is expected 10/26/2007 to include a fix patterns with Regex meta-characters and ability to build compiled UriPatterns.

What the heck is this all about?

How to use

using System;
using System.Collections;
using System.Collections.Generic;
 
using UriTemplate;
 
namespace TestJig
{
    public class Program
    {
        static void Main(string[] args)
        {
            UriPattern p = UriPattern.Create("/{user}/{year}/{month}");
            IDictionary<string, string> values = p.Parse("/marc/2007/06?no#touch");
            foreach (KeyValuePair<string, string> item in values)
            {
                System.Console.WriteLine(item.Key.ToString() + " = " + item.Value.ToString());
            }
            IResolver resolver = new DictionaryResolver(values);
            string url =  UriTemplate.UriTemplate.Expand("http://localhost/paystub/{year}/{month}/{user}", resolver);
            System.Console.WriteLine(url);
        }
    }
}

Other blog entries

UPDATED WIKI: Home

IDisposable — Fri, 26 Oct 2007 06:40:55 GMT

Project Description

The UriTemplate library is a simple set of code to encapsulate the building and parsing of URIs from replacement tokens. Using this couple of classes will make it easy to build RESTful URIs.

What the heck is this all about?

How to use

using System;
using System.Collections;
using System.Collections.Generic;
 
using UriTemplate;
 
namespace TestJig
{
    public class Program
    {
        static void Main(string[] args)
        {
            UriPattern p = UriPattern.Create("/{user}/{year}/{month}");
            IDictionary<string, string> values = p.Parse("/marc/2007/06?no#touch");
            foreach (KeyValuePair<string, string> item in values)
            {
                System.Console.WriteLine(item.Key.ToString() + " = " + item.Value.ToString());
            }
            IResolver resolver = new DictionaryResolver(values);
            string url =  UriTemplate.UriTemplate.Expand("http://localhost/paystub/{year}/{month}/{user}", resolver);
            System.Console.WriteLine(url);
        }
    }
}

Other blog entries

UPDATED RELEASE: 1.1 Release

Fri, 26 Oct 2007 06:38:44 GMT

UPDATED RELEASE: 1.1 Release

Fri, 26 Oct 2007 06:38:00 GMT

Corrects problems with Regex metacharacters in pattern strings (like parenthesis). Add option to specify a UriTemplate to use the compile Regex option if it gets used a lot.

Source code checked in

IDisposable — Fri, 26 Oct 2007 06:29:48 GMT

Create actual 1.1 Release branch

Source code checked in

IDisposable — Fri, 26 Oct 2007 06:28:00 GMT

Synch back (with no change)

Source code checked in

IDisposable — Fri, 26 Oct 2007 06:26:23 GMT

Corrected build target info for this branch

Source code checked in

IDisposable — Fri, 26 Oct 2007 06:25:10 GMT

Bump version number and note build target in assembly metadata.

Source code checked in

IDisposable — Fri, 26 Oct 2007 06:23:14 GMT

Prepare 1.1 Release

Source code checked in

IDisposable — Fri, 26 Oct 2007 06:20:35 GMT

Sync forward again

Source code checked in

IDisposable — Fri, 26 Oct 2007 06:19:39 GMT

Sync back from 1.1 to keep tree synched

CLOSED FEATURE: Option to make UriTemplates compiled

IDisposable — Fri, 26 Oct 2007 06:12:17 GMT

When a UriTemplate is going to be used over and over, it would be nice to allow the template to be specified as a compiled pattern

Source code checked in

IDisposable — Fri, 26 Oct 2007 06:12:16 GMT

Merge changes back from 2.0 branch for optionally compiled patterns

REOPENED FEATURE: Option to make UriTemplates compiled

IDisposable — Fri, 26 Oct 2007 06:12:03 GMT

When a UriTemplate is going to be used over and over, it would be nice to allow the template to be specified as a compiled pattern
Comments: ** Comment from web user: IDisposable **

Want to merge changes back from 2.0 branch

COMMENTED FEATURE: Option to make UriTemplates compiled

IDisposable — Fri, 26 Oct 2007 06:12:03 GMT

When a UriTemplate is going to be used over and over, it would be nice to allow the template to be specified as a compiled pattern
Comments: ** Comment from web user: IDisposable **

** Closed by IDisposable 10/25/2007 10:12 PM