Lazarus: Get HTML of a Website

You can just use fphttpclient which is part of the fcl-web package and therefore automatically included in FreePascal and Lazarus without need to install additional components or libraries. You just have to add "fphttpclient" to the uses clause of your unit.

Here is a simple example:

uses fphttpclient;
  
procedure TForm1.Button1Click(Sender: TObject);
var
  url, html : String;
begin
  url := 'http://www.example.com';
  html := TFPCustomHTTPClient.SimpleGet(url);
  memo1.Text := html;
end;

In this example, we are picking the HTML code from example.com in order to show it within a memo. For this, we are using the class function SimpleGet of TFPCustomHTTPClient which allow us to do the job within only one line of code.

Of course, you can also go the detailed way:

uses fphttpclient;

procedure TForm1.Button2Click(Sender: TObject);
var
  httpclient: TFPHTTPClient;
  url, html : String;
begin

  url := 'http://www.example.com';

  httpclient := TFPHttpClient.Create(Nil);
  try
    html := httpclient.Get(url);
  finally
    httpclient.Free;
  end;

  memo1.Text := html;

end;   

In both cases, the result is the same. The second example is a little bit longer but you can use it as a basis if you would like to extend the code in some way.
2015-03-23 at 12:37