Docs For Class HTTP_Headers

Description

HTTP Headers Util - Header value parsing utility functions

This class is based on HTTP::Headers::Util from Perl's LWP <http://search.cpan.org/author/GAAS/libwww-perl-5.65/lib/HTTP/Headers/Util.pm> by Gisle Aas. The text here is copied from the documentation of the above, obviously slightly modified as this is PHP not Perl.

SYNOPSIS


1      $values = HTTP_Headers_Util::split_header_words($header_value);

DESCRIPTION

This class provides a few functions that helps parsing and construction of valid HTTP header values.

static:

Located in Program_Root/HTTP_Headers_Util.php (line 45)

Method Summary

string join_header_words (array $header_values)

array split_header_words (mixed $header_values)

Methods

join_header_words (line 170)

join_header_words

This will do the opposite of the conversion done by split_header_words(). It takes a list of anonymous arrays as arguments (or a list of key/value pairs) and produces a single header value. Attribute values are quoted if needed.

Example:


1         join_header_words(array(array("text/plain" => null, "charset" => "iso-8859/1")));
2         join_header_words(array("text/plain" => null, "charset" => "iso-8859/1"));

will both return the string:

    text/plain; charset="iso-8859/1"

static:

string join_header_words (array $header_values)

array $header_values

split_header_words (line 102)

split_header_words

This function will parse the header values given as argument into a array containing key/value pairs. The function knows how to deal with ",", ";" and "=" as well as quoted values after "=". A list of space separated tokens are parsed as if they were separated by ";".

If the $header_values passed as argument contains multiple values, then they are treated as if they were a single value separated by comma ",".

This means that this function is useful for parsing header fields that follow this syntax (BNF as from the HTTP/1.1 specification, but we relax the requirement for tokens).

   headers           = #header
   header            = (token | parameter) *( [";"] (token | parameter))

   token             = 1*
   separators        = "(" | ")" | "<" | ">" | "@"
                     | "," | ";" | ":" | "\" | <">
                     | "/" | "[" | "]" | "?" | "="
                     | "{" | "}" | SP | HT

   quoted-string     = ( <"> *(qdtext | quoted-pair ) <"> )
   qdtext            = >
   quoted-pair       = "\" CHAR

   parameter         = attribute "=" value
   attribute         = token
   value             = token | quoted-string

Each header is represented by an anonymous array of key/value pairs. The value for a simple token (not part of a parameter) is null. Syntactically incorrect headers will not necessary be parsed as you would want.

This is easier to describe with some examples:


1         split_header_words('foo="bar"; port="80,81"; discard, bar=baz');
2         split_header_words('text/html; charset="iso-8859-1");
3         split_header_words('Basic realm="\"foo\\bar\""');

will return

    [foo=>'bar', port=>'80,81', discard=>null], [bar=>'baz']
    ['text/html'=>null, charset=>'iso-8859-1']
    [Basic=>null, realm=>'"foo\bar"']

static:

array split_header_words (mixed $header_values)

mixed $header_values:
string or array

Class HTTP_Headers_Util