Difference between revisions of "fphttpclient"
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* If you do not use client side certificates, just specifying the proper port (e.g. 443 for https) is enough to enable TLS/SSL as long as you have [https://wiki.openssl.org/index.php/Binaries OpenSSL libraries] installed (or e.g. in the application directory) | * If you do not use client side certificates, just specifying the proper port (e.g. 443 for https) is enough to enable TLS/SSL as long as you have [https://wiki.openssl.org/index.php/Binaries OpenSSL libraries] installed (or e.g. in the application directory) | ||
* If you want to use e.g. a client side certificate, do something like this: | * If you want to use e.g. a client side certificate, do something like this: | ||
| − | <syntaxhighlight> | + | <syntaxhighlight lang="pascal"> |
uses ...ssockets, sslsockets.. | uses ...ssockets, sslsockets.. | ||
// Callback for setting up SSL client certificate | // Callback for setting up SSL client certificate | ||
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=== Get body of a web page via HTTP protocol === | === Get body of a web page via HTTP protocol === | ||
| − | <syntaxhighlight> | + | <syntaxhighlight lang="pascal"> |
uses fphttpclient; | uses fphttpclient; | ||
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If you want to write even less lines of code, in FPC 2.7.1 you can use the class method: | If you want to write even less lines of code, in FPC 2.7.1 you can use the class method: | ||
| − | <syntaxhighlight> | + | <syntaxhighlight lang="pascal"> |
s := TFPCustomHTTPClient.SimpleGet('http://a_site/a_page'); | s := TFPCustomHTTPClient.SimpleGet('http://a_site/a_page'); | ||
</syntaxhighlight> | </syntaxhighlight> | ||
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=== Upload a file using POST === | === Upload a file using POST === | ||
Use TFPHTTPClient.FileFormPost() | Use TFPHTTPClient.FileFormPost() | ||
| − | <syntaxhighlight> | + | <syntaxhighlight lang="pascal"> |
uses fphttpclient; | uses fphttpclient; | ||
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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: [http://lazarus.freepascal.org/index.php/topic,17506.msg110917.html#msg110917]): | 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: [http://lazarus.freepascal.org/index.php/topic,17506.msg110917.html#msg110917]): | ||
| − | <syntaxhighlight> | + | <syntaxhighlight lang="pascal"> |
{$mode objfpc}{$H+} | {$mode objfpc}{$H+} | ||
Revision as of 07:47, 18 June 2019
Overview
fphttpclient is supplied with FPC as part of the fcl-web package, and can be used by itself as well.
HTTPS (TLS/SSL)
Since April 2014, the trunk/development fphttpclient supports SSL/TLS connections using the OpenSSL library (will ship with version 2.8.0 and above). This requires the OpenSSL .so/.dll/.dylib library/libraries to be installed (e.g. present in your application or system directory on Windows).
- If you do not use client side certificates, just specifying the proper port (e.g. 443 for https) is enough to enable TLS/SSL as long as you have OpenSSL libraries installed (or e.g. in the application directory)
- If you want to use e.g. a client side certificate, do something like this:
uses ...ssockets, sslsockets..
// Callback for setting up SSL client certificate
procedure TSSLHelper.SSLClientCertSetup(Sender: TObject; const UseSSL: Boolean;
out AHandler: TSocketHandler);
begin
AHandler := nil;
if UseSSL and (FClientCertificate <> '') then
begin
// Only set up client certificate if needed.
// If not, let normal fphttpclient flow create
// required socket handler
AHandler := TSSLSocketHandler.Create;
// Example: use your own client certificate when communicating with the server:
(AHandler as TSSLSocketHandler).Certificate.FileName := FClientCertificate;
end;
end;
//... and in your TFPHTTPClient creation:
myclient := TFPHTTPClient.Create(nil);
if FClientCertificate <> '' then
myclient.OnGetSocketHandler := @SSLClientCertSetup;
Examples
Examples are included in your FPC directory: packages/fcl-web/examples/
Apart from those, please see below:
Get body of a web page via HTTP protocol
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()
uses fphttpclient;
Var
Respo: TStringStream;
S : String;
begin
With TFPHttpClient.Create(Nil) do
try
Respo := TStringStream.Create('');
FileFormPost('http://example.com/upload.php','PostFilenameParam (ex. 'file')',edtSourceFile.Text,Respo);
S := Respo.DataString;
Respo.Destroy;
finally
Free;
end;
end.
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.
