Name¶
lua-uri-_util - Utility functions for Lua URI library
Description¶
This module contains various utility functions used by the rest of the library.
They are mostly intended only for internal use, and are subject to change in
future versions, but the URI encoding and decoding functions may be more
widely useful.
On loading, the module returns a table containing the functions, but like all
the modules in this library it does not install itself into any global
variables.
local Util = require "uri._util"
Functions¶
The following functions can be found in the table returned from
"require":
- uri_encode(text, pattern)
- Use URI encoding (or 'percent encoding') to encode any unsafe characters
in "text". If "pattern" is specified then it should be
part of a Lua pattern which can be enclosed in square brackets to make a
character class. Usually it will start with "^" so that the rest
of the characters will be considered the 'safe' ones, not to be encoded.
Any character matched by the pattern will be encoded.
print(Util.uri_encode("foo bar!"))
---> foo%20bar!
print(Util.uri_encode("foo bar!", "^A-Za-z0-9"))
---> foo%20bar%21
The default pattern is: "^A-Za-z0-9%-_.!~*'()"
- uri_decode(text, pattern)
- Decode any URI encoding in "text". If "pattern" is nil
then all encoded characters will be decoded. If a pattern is supplied then
it should be in the same form as for "uri_encode". Any character
not matched by the pattern will be left encoded as it was.
print(Util.uri_decode("foo%20bar%21"))
---> foo bar!
print(Util.uri_decode("foo%20bar%21", "^!"))
---> foo bar%21
- remove_dot_segments(path)
- Removes single and double dot segments from a URI path.
This is the 'remove_dot_segments' algorithm from "RFC 3986 section
5.2.4". The value of "path" is used as the input buffer,
and the contents of the output buffer are returned.
- split(pattern, str, max)
- Split the string "str" wherever "pattern" matches it,
returning the pieces as individual strings in an array. If "max"
is not nil, then stop splitting after that many pieces have been
created.
- attempt_require(name)
- Calling this function is the same as calling Lua's built in
"require" function, except that if a module called
"name" cannot be found, it returns nil instead of throwing an
exception. If loading the module is successful then the result of
"require" is returned. An exception is thrown if any error
occurs loading the module other than it not being found.
- subclass_of(class, baseclass)
- Sets up the metatable and a few other things for the table
"class" so that it will be a subclass of "baseclass".
This is used by the classes in this library to implement inheritance.
- do_class_changing_change(uri, baseclass, changedesc, newvalue,
changefunc)
- This is used when a mutator method changes something about a URI which
leads it to need to belong to a different class. "uri" is the
URI object to change, "baseclass" is the class to reset it to
before making the change, "changedesc" is a description to be
included in an error message if necessary, "newvalue" is the new
value to be set (which must be a string, as it is also included in error
messages), and "changefunc" is a function which is called with a
temporary URI object it should adjust and "newvalue".
- uri_part_not_allowed (class, method)
- This should be called in scheme-specific classes where certain parts of
URIs are not allowed to be present (e.g., the 'host' part in a URN). It
will override the named method in the class with one which throws an
exception if an attempt is made to set the part to anything other than
nil. If the rest of the code for the scheme keeps objects internally
consistent then the new method should always return nil, although when a
URI is being validated during the "init" method's execution, it
may return other things, which can be used to detect disallowed parts in a
URI being parsed.