fphttpclient
Overview
fphttpclient is supplied with FPC as part of the fcl-web package, and can be used by itself as well.
Since April 2014, the trunk/development fphttpclient supports SSL/TLS connections using the OpenSSL library. This requires the OpenSSL .so/.dll/.dylib library/libraries to be installed (e.g. present in your application directory on Windows).
Examples
Examples are included in your FPC directory: packages/fcl-web/examples/
Apart from those, please see below:
Get body of an HTTP page
uses fphttpclient;
Var
S : String;
begin
With TFPHttpClient.Create(Nil) do
try
S:=Get(ParamStr(1));
finally
Free;
end;
Writeln('Got : ',S);
end.
If you want to write even less lines of code, in FPC 2.7.1 you can use the class method:
s := TFPCustomHTTPClient.SimpleGet('http://a_site/a_page');
Upload a file using POST
Use TFPHTTPClient.FileFormPost() to do: add exact example code
Get external IP address
If your computer is connected to the internet via a LAN (cabled or wireless), the IP address of your network card most probably is not your external IP address.
You can retrieve your external IP address from e.g. your router or an external site. The code below tries to get it from an external site (thanks to JoStudio on the forum for the inspiration: [1]):
{$mode objfpc}{$H+}
uses
Classes, SysUtils, fphttpclient, RegexPr;
function GetExternalIPAddress: string;
var
HTTPClient: TFPHTTPClient;
IPRegex: TRegExpr;
RawData: string;
begin
try
HTTPClient:=TFPHTTPClient.Create(nil);
IPRegex:=TRegExpr.Create;
try
//returns something like:
{
<html><head><title>Current IP Check</title></head><body>Current IP Address: 44.151.191.44</body></html>
}
RawData:=HTTPClient.Get('http://checkip.dyndns.org');
// adjust for expected output; we just capture the first IP address now:
IPRegex.Expression:=RegExprString('\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b');
//or
//\b(?:\d{1,3}\.){3}\d{1,3}\b
if IPRegex.Exec(RawData) then
begin
result:=IPRegex.Match[0];
end
else
begin
result:='Got invalid results getting external IP address. Details:'+LineEnding+
RawData;
end;
except
on E: Exception do
begin
result:='Error retrieving external IP address: '+E.Message;
end;
end;
finally
HTTPClient.Free;
IPRegex.Free;
end;
end;
begin
writeln('External IP address:');
writeln(GetExternalIPAddress);
end.