wwHTTP::HTTPGetHeader

Retrieves an HTTP header from a URL. Useful for retrieving information about a request prior to actually downloading the full URL. You can spy the content length from the header for example.

In download scenarios, you might want to use the cHTTPHeaders property and the OnHTTPBufferUpdate() event to trap for the HTTP header as part of a running request. The first buffer grab returns the HTTP header.

The cHTTPHeaders property is also set by this method so passing in the 2nd and 3rd parameters is optional.

Syntax:

o.httpgetheader(tcPage, tcHeaders, tnHeaderSize)

Return: 0 on success, an error number on failure

Parameters: tcPage
The Web relative page to access.
@tcHeaders
Buffer that will receive the headers. This buffer must be presized to the size that you expect and passed in by reference
@tnHeaderSize
Buffer that receives the byte size of the header returned. Pass by reference to retrieve the size of the result header.

Example:
oIP=create("wwHTTP") oIP.httpconnect("www.cdw.com") lnSize = 5000 lcHeaders = space(5000) oIP.httpGetHeader("/",@lcHeaders,@lnSize) ? lcHeaders ? "Content Length: ",; VAL( Extract(lcHeaders,"Content-Length:",CHR(13)) ) RETURN

See also:

Class wwHTTP

Syntax:	o.httpgetheader(tcPage, tcHeaders, tnHeaderSize)
Return:	0 on success, an error number on failure
Parameters:	tcPage The Web relative page to access. @tcHeaders Buffer that will receive the headers. This buffer must be presized to the size that you expect and passed in by reference @tnHeaderSize Buffer that receives the byte size of the header returned. Pass by reference to retrieve the size of the result header.
Example:	oIP=create("wwHTTP") oIP.httpconnect("www.cdw.com") lnSize = 5000 lcHeaders = space(5000) oIP.httpGetHeader("/",@lcHeaders,@lnSize) ? lcHeaders ? "Content Length: ",; VAL( Extract(lcHeaders,"Content-Length:",CHR(13)) ) RETURN