Manual of Lua-URI: data

lua-uri-data - data URI support for Lua URI library

Description

The class uri.data is used for URIs with the data scheme. It inherits from the uri class.

Some of the features of this module require the lua-datafilter(3) library to be installed, but URI objects can still be created from data URIs even if it isn't available.

Any data URI containing an authority part is considered to be invalid, as is one whose path does not contain a comma. If the URI has the ;base64 parameter, then the data must consist only of characters allowed in base64 encoded data (upper and lowercase ASCII letters, digits, and the forward slash and plus characters).

Methods

All the methods defined in lua-uri(3) are supported. The userinfo, host, and port methods will always return nil, and will throw an exception when passed anything other than nil. The path method will throw an exception if given a new path which is nil or not valid for the data scheme.

The following additional methods are supported:

uri:data_bytes(...)

Get or set the data stored in the URI. The existing data is decoded and returned. If a new value is supplied it must be a string, and will cause the path of the URI to be changed to encode the new data. The method will choose the encoding which will result in the smallest URI, unless the datafilter module is not installed, in which case it will always use percent encoding.

An exception is thrown if the datafilter module is not installed and the data in the URI is encoded as base64, although a data URI using percent encoding will not cause an exception.

The data passed in and returned should not be encoded in any special way, that is taken care of by the library.

uri:data_media_type(...)

Get or set the media type (MIME type) stored in the URI's path before the comma. This should not include the ;base64 parameter, which will be included in the path automatically when appropriate.

If there is no media type given in the URI then the default value of text/plain will be returned, and if there is no charset parameter given then the default ;charset=US-ASCII will be included.

The media type is encoded and decoded automatically by this method.

References

This class is based on RFC 2397.