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vfs.open-http |
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Library: File system utilities (OMVFS)
Import: omvfs.xmd |
Return type: vfsFile Returns: A VFS file object for the opened file. |
export external file function open-http
value string URL
on value directory on-dir optional
with-headers read-only stream headers optional
post value string postdata optional
as-raw value switch raw optional initial {false}
for value integer access-type optional initial {read-mode}
user value string user optional
password value string pass optional
proxy value string proxy optional
Argument definitions
You can use vfs.open-http to open a file that resides on an HTTP server. vfs.open-http creates a vfs.file object that represents the file, and which can be used with various OMVFS functions to manipulate the file.
import "omvfs.xmd" prefixed by vfs.
process
local vfs.file input-file
set input-file to vfs.open-http "http://www.stilo.com/"
submit vfs.reader of input-file
Note that the OMVFS library functions do not do "URL fix-up", which means that the URL "http://www.stilo.com" (without the final slash) will not be accepted. Nor will a URL that lacks the introductory "http://".
You may specify the mode in which the file is opened. The default mode is read mode. The following modes are available:
Note that not all OMVFS functions are supported by all protocols. You will receive a runtime error if you attempt to perform an operation on a file on an http server if that operation is not supported by the http protocol, or if that function is not supported in the current version of OMVFS. In the current implementation, the following functions are supported:
You can use vfs.open-http to make either a GET or POST request. The default is a GET request. If you supply POST data using the optional postdata argument (heralded by post), then a POST request is made.
You can supply additional headers to a POST or GET request by specifying set of headers using the optional headers argument (heralded by with-headers). The headers argument takes a keyed stream shelf with one header per item and header names as keys.
By default, vfs.open-http generates a minimum necessary set of HTTP headers to create a valid HTTP request, and it strips out any HTTP headers received in an HTTP response. If you specify raw mode by passing a value of true to the optional raw argument (heralded by as-raw, then OMVFS will neither generate or strip headers. You will be responsible for generating the appropriate headers and for interpreting the response.
import "omvfs.xmd" prefixed by vfs.
process
local stream headers variable
local vfs.file input-file
set new headers{"Host"} to "www.stilo.com"
set input-file
to vfs.open-http "http://www.stilo.com/"
with-headers headers
as-raw true
submit vfs.reader of input-file
An HTTP request may return an error code in the form of an HTTP response code. In normal mode, OMVFS will generate a runtime exception VFS400 if it receives an HTTP response code greater than 299. You can examine the error message to determine the error code. In raw mode, OMVFS does not examine the HTTP response code. It is your responsibility to scan the returned data and determine if the expected HTTP response code was received.
The following exceptions may occur:
Copyright © Stilo International plc, 1988-2010.
