Added option to fetch website content.

Author: dryas

README.md

@@ -2,7 +2,7 @@
 
 ![Example Application](https://github.com/dryas/LazSimpleHTTPsGet/blob/main/doc/example_screenshot.png)
 
-LazSimpleHTTPsGet is a simple asynchronous (threads) file download Unit with progress indicator for Lazarus/Free Pascal. It supports downloads from HTTP and HTTPS sources and the developer can choose if he wants to use Ararat Synapse or FCL/TFPHttpClient in the background. That said it supports OpenSSLv1 and OpenSSLv3.
+LazSimpleHTTPsGet is a simple asynchronous (threads) file download and content fetch (e.g. website source, JSON, XML etc.) Unit with progress indicator for Lazarus/Free Pascal. It supports downloads from HTTP and HTTPS sources and the developer can choose if he wants to use Ararat Synapse or FCL/TFPHttpClient in the background. That said it supports OpenSSLv1 and OpenSSLv3.
 
 The Unit has been tested with Windows but should also work on other Systems which are supported by FCL/TFPHttpClient or Synapse (Linux, Mac etc.).
 

doc/example_screenshot.png

@@ -98,6 +98,9 @@
       <Item>
         <PackageName Value="FCL"/>
       </Item>
+      <Item>
+        <PackageName Value="laz_synapse"/>
+      </Item>
       <Item>
         <PackageName Value="LCL"/>
       </Item>

example/Example.lpi

@@ -1,20 +1,20 @@
 object MainForm: TMainForm
   Left = 350
-  Height = 269
+  Height = 348
   Top = 250
   Width = 517
   BorderStyle = bsSingle
   Caption = 'LazSimpleHTTPsGet'
-  ClientHeight = 269
+  ClientHeight = 348
   ClientWidth = 517
   OnDestroy = FormDestroy
   object GroupBox1: TGroupBox
     Left = 8
-    Height = 256
+    Height = 336
     Top = 8
     Width = 504
     Caption = 'Download File Example'
-    ClientHeight = 236
+    ClientHeight = 316
     ClientWidth = 500
     TabOrder = 0
     object DownloadProgressLabel: TLabel
@@ -33,7 +33,7 @@ object MainForm: TMainForm
     end
     object StatusInfoMemo: TMemo
       Left = 112
-      Height = 64
+      Height = 152
       Top = 112
       Width = 374
       ReadOnly = True
@@ -43,9 +43,9 @@ object MainForm: TMainForm
     object DownloadBtn: TButton
       Left = 112
       Height = 33
-      Top = 192
-      Width = 184
-      Caption = 'Start Download'
+      Top = 272
+      Width = 104
+      Caption = 'Download File'
       TabOrder = 2
       OnClick = DownloadBtnClick
     end
@@ -78,15 +78,23 @@ object MainForm: TMainForm
       Caption = 'Progress:'
     end
     object StopBtn: TButton
-      Left = 302
+      Left = 374
       Height = 33
-      Top = 192
-      Width = 184
+      Top = 272
+      Width = 112
       Caption = 'Stop Download'
-      Enabled = False
       TabOrder = 4
       OnClick = StopBtnClick
     end
+    object FetchBtn: TButton
+      Left = 240
+      Height = 33
+      Top = 272
+      Width = 104
+      Caption = 'Fetch Content'
+      TabOrder = 5
+      OnClick = FetchBtnClick
+    end
   end
   object SaveDialog: TSaveDialog
     Left = 40

example/main.lfm

@@ -41,6 +41,7 @@ interface
   { TMainForm }
 
   TMainForm = class(TForm)
+    FetchBtn: TButton;
     StopBtn: TButton;
     DownloadBtn: TButton;
     DownloadProgressLabel: TLabel;
@@ -52,11 +53,12 @@   TMainForm = class(TForm)
     ProgressStaticLabel: TLabel;
     URLEdit: TEdit;
     UrlStaticLabel: TLabel;
+    procedure FetchBtnClick(Sender: TObject);
     procedure StopBtnClick(Sender: TObject);
     procedure DownloadBtnClick(Sender: TObject);
     procedure FormDestroy(Sender: TObject);
     procedure UpdateProgress(ALen, APos: Int64; AHRLen, AHRPos: String);
-    procedure UpdateStatus(Status: TStatus; ResponseCode: Integer; Msg: String);
+    procedure UpdateStatus(Status: TStatus; ResponseCode: Integer; Msg: String; Body: String);
   private
     LazSimpleHTTPsGet: TLazSimpleHTTPsGet;
   public
@@ -78,9 +80,12 @@ procedure TMainForm.DownloadBtnClick(Sender: TObject);
   Filename: String;
 begin
   try
-    if not Assigned(LazSimpleHTTPsGet) then
+    if Length(URLEdit.Text) > 0 then
     begin
-      LazSimpleHTTPsGet := TLazSimpleHTTPsGet.Create();
+      if not Assigned(LazSimpleHTTPsGet) then
+      begin
+        LazSimpleHTTPsGet := TLazSimpleHTTPsGet.Create();
+      end;
 
       Filename := LazSimpleHTTPsGet.GetFileNameFromURL(URLEdit.Text);
       SaveDialog.FileName := Filename;
@@ -90,14 +95,20 @@ procedure TMainForm.DownloadBtnClick(Sender: TObject);
         LazSimpleHTTPsGet.Filename := SaveDialog.FileName;
         LazSimpleHTTPsGet.OnProgress := @UpdateProgress;
         LazSimpleHTTPsGet.onStatus := @UpdateStatus;
-        LazSimpleHTTPsGet.Start;
-        DownloadBtn.Enabled := False;
-        StopBtn.Enabled := True;
+        if LazSimpleHTTPsGet.Get then
+        begin
+          DownloadBtn.Enabled := False;
+          StopBtn.Enabled := True;
+        end
+        else
+        begin
+          ShowMessage('Download already running');
+        end;
       end;
     end
     else
     begin
-      ShowMessage('Download already running');
+      ShowMessage('Please enter a url');
     end;
   except
     on E: Exception do
@@ -112,7 +123,6 @@ procedure TMainForm.StopBtnClick(Sender: TObject);
 begin
   if Assigned(LazSimpleHTTPsGet) then
   begin
-    LazSimpleHTTPsGet.Stop;
     StatusInfoMemo.Append('Download stopped');
     FreeAndNil(LazSimpleHTTPsGet);
     DownloadBtn.Enabled := True;
@@ -122,12 +132,46 @@ procedure TMainForm.StopBtnClick(Sender: TObject);
   end;
 end;
 
+procedure TMainForm.FetchBtnClick(Sender: TObject);
+begin
+  try
+    if Length(URLEdit.Text) > 0 then
+    begin
+      if not Assigned(LazSimpleHTTPsGet) then
+      begin
+        LazSimpleHTTPsGet := TLazSimpleHTTPsGet.Create();
+      end;
+
+      LazSimpleHTTPsGet.URL := URLEdit.Text;
+      LazSimpleHTTPsGet.OnProgress := @UpdateProgress;
+      LazSimpleHTTPsGet.onStatus := @UpdateStatus;
+      if LazSimpleHTTPsGet.Fetch then
+      begin
+        DownloadBtn.Enabled := False;
+        StopBtn.Enabled := True;
+      end
+      else
+      begin
+        ShowMessage('Download already running');
+      end;
+    end
+    else
+    begin
+      ShowMessage('Please enter a url');
+    end;
+  except
+    on E: Exception do
+    begin
+      ShowMessage(E.Message);
+    end;
+  end;
+end;
+
 // Form closed, stop downloads and free and nil LazSimpleHTTPsGet:
 procedure TMainForm.FormDestroy(Sender: TObject);
 begin
   if Assigned(LazSimpleHTTPsGet) then
   begin
-    LazSimpleHTTPsGet.Stop;
     FreeAndNil(LazSimpleHTTPsGet);
   end;
 end;
@@ -146,7 +190,7 @@ procedure TMainForm.UpdateProgress(ALen, APos: Int64; AHRLen, AHRPos: String);
 end;
 
 // Status event (download start, done, error):
-procedure TMainForm.UpdateStatus(Status: TStatus; ResponseCode: Integer; Msg: String);
+procedure TMainForm.UpdateStatus(Status: TStatus; ResponseCode: Integer; Msg: String; Body: String);
 begin
   if Status = TStatus.sStart then
   begin
@@ -155,6 +199,14 @@ procedure TMainForm.UpdateStatus(Status: TStatus; ResponseCode: Integer; Msg: St
   else if Status = TStatus.sDone then
   begin
     StatusInfoMemo.Append('Download done -> (HTTP Status: ' + IntToStr(ResponseCode) + '/' + Msg + ')');
+    if Length(Body) > 0 then
+    begin
+      StatusInfoMemo.Append('-- Body Start ------------------');
+      StatusInfoMemo.Append(Body);
+      StatusInfoMemo.Append('-- Body End --------------------');
+    end;
+    DownloadBtn.Enabled := True;
+    StopBtn.Enabled := False;
     DownloadProgressLabel.Caption := '-/-';
     ProgressBar.Position := 0;
   end