ObjectMethod finish ()

getExternalResource( $url ) -> $response

Get whatever is at the other end of a URL (using an HTTP GET request). Will only work for encrypted protocols such as https if the LWP CPAN module is installed.

Note that the $url may have an optional user and password, as specified by the relevant RFC. Any proxy set in configure is honoured.

The $response is an object that is known to implement the following subset of the methods of LWP::Response. It may in fact be an LWP::Response object, but it may also not be if LWP is not available, so callers may only assume the following subset of methods is available:

code()

message()

header($field)

content()

is_error()

is_redirect()

Note that if LWP is not available, this function:

1. can only really be trusted for HTTP/1.0 urls. If HTTP/1.1 or another protocol is required, you are strongly recommended to require LWP.
2. Will not parse multipart content

In the event of the server returning an error, then is_error() will return true, code() will return a valid HTTP status code as specified in RFC 2616 and RFC 2518, and message() will return the message that was received from the server. In the event of a client-side error (e.g. an unparseable URL) then is_error() will return true and message() will return an explanatory message. code() will return 400 (BAD REQUEST).

Note: Callers can easily check the availability of other HTTP::Response methods as follows:

my $response = TWiki::Func::getExternalResource($url);
if (!$response->is_error() && $response->isa('HTTP::Response')) {
    ... other methods of HTTP::Response may be called
} else {
    ... only the methods listed above may be called
}