PackageDescription: NetResources

Net Resources

Last published: January 27, 2016 by 'niallr'

Defines 19 Classes
Extends 33 Classes

NetResources provides a simple API for accessing content via URIs.

NetResources can transform the content of a URI into a relevant object. For example:

'' asURI asResource

This package can use the following other packages:
a) GIFSupport - for viewing GIF images
b) WinGDIPlusInterface - for viewing many kinds of images. Windows only. Needs the gdi+.dll
c) LibTidy or Twoflower - for viewing badly formed XML and HTML and using HTML entities
d) PNGImageReader - for viewing PNG images

This package does not provide HTTP behaviour, see NetResourcesHTTP to use the API with HTTP. NetResources works with URIs. It currently supports File URLs, HTTP URLs and Resource URLs. It does not work with FTP URLs at present.

NetResources provides a new kind of URI called a 'resource' URI. It works like so:


Accessing this URI sends myClassMethod to MyClass. For a POST, the same method name is called except with a : (i.e., myClassMethod:) and an argument that contains the parameters of the post.

NetResources has an in-memory and on-disk cache mechanism using CacheItem objects. If the directory './cache' exists then instances of CacheItem are written to disk for later retrieval if the CacheItem is not already in memory. A CacheItem checks its own timestamp to ensure the content is not out of date.

NetResources provides the following API for URIs:

#asResourceInEncoding: anEncoding
#asResourceInMimeType: aMimeType
#asResourceInMimeType: aMimeType encoding: anEncoding
#post: contents
#post: contents encoding: anEncoding
#put: contents
#put: contents encoding: anEncoding

Converting the contents of a URL into a Resource object such as an XML DOM tree or an Image object is done using a ResourceHandler. All ResourcesHandlers are subclasses of ResourceHandler. A specific ResourceHandler is picked based on the MimeType of a URI. For File URIs, this is guessed from the filename extension. For HTTP, the HTTP request itself gives the mime type, etc. Each ResourceHandler class must implement the class-side method #canHandle: to say whether that class can handle a given mime type for a URI. On the instance side, a ResourceHandler must implement #handle: contents for: aURI to return the object of interest for a URIs contents.

The intent of this document is to state the conditions under which a Package may be copied, such that the Copyright Holder maintains some semblance of artistic control over the development of the package, while giving the users of the package the right to use and distribute the Package in a more-or-less customary fashion, plus the right to make reasonable modifications.


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* "Freely Available" means that no fee is charged for the item itself, though there may be fees involved in handling the item. It also means that recipients of the item may redistribute it under the same conditions they received it.

1. You may make and give away verbatim copies of the source form of the Standard Version of this Package without restriction, provided that you duplicate all of the original copyright notices and associated disclaimers.

2. You may apply bug fixes, portability fixes and other modifications derived from the Public Domain or from the Copyright Holder. A Package modified in such a way shall still be considered the Standard Version.

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10. The user must assume all risk of using this package

The End

Copyright Holders: Software WithStyle, James Robertson