How to read a text file from the Internet resource? - download

I would like to read a text file containing a version number from the Internet resource. Then I need to use this version number within my script.
How to do this in InnoSetup ?

There are many ways how to get a file from the Internet in InnoSetup. You can use an external library like for instance InnoTools Downloader, write your own library, or use one of the Windows COM objects. In the following example I've used the WinHttpRequest COM object for file receiving.
The DownloadFile function in this script returns True, when the WinHTTP functions doesn't raise any exception, False otherwise. The response content of the HTTP GET request to an URL, specified by the AURL parameter is then passed to a declared AResponse parameter. When the script fails the run on exception, AResponse parameter will contain the exception error message:
[Code]
function DownloadFile(const AURL: string; var AResponse: string): Boolean;
var
WinHttpRequest: Variant;
begin
Result := True;
try
WinHttpRequest := CreateOleObject('WinHttp.WinHttpRequest.5.1');
WinHttpRequest.Open('GET', AURL, False);
WinHttpRequest.Send;
AResponse := WinHttpRequest.ResponseText;
except
Result := False;
AResponse := GetExceptionMessage;
end;
end;
procedure InitializeWizard;
var
S: string;
begin
if DownloadFile('http://www.example.com/versioninfo.txt', S) then
MsgBox(S, mbInformation, MB_OK)
else
MsgBox(S, mbError, MB_OK)
end;

Related

How to continue download on error in Inno Setup?

My Inno Setup script downloads some resources using built-in functionalities.
It creates Download Wizard Page:
DownloadPage := CreateDownloadPage(SetupMessage(msgWizardPreparing), SetupMessage(msgPreparingDesc), #OnDownloadProgress);
It adds several items that should be downloaded:
if WizardIsTaskSelected('taskA') then
begin
DownloadPage.Add('https://randomresource/taskA.zip', 'taskA.zip', '');
end;
if WizardIsTaskSelected('taskB') then
begin
DownloadPage.Add('https://randomresource/taskB.zip', 'taskB.zip', '');
end;
and last step is to show the Wizard Page and start downloading:
try
try
DownloadPage.Download;
Result := True;
except
SuppressibleMsgBox(AddPeriod(GetExceptionMessage), mbCriticalError, MB_OK, IDOK);
Result := False;
end;
finally
DownloadPage.Hide;
end;
All of the above is basically from examples provided by Inno Setup. There is one issue: if any of the downloads fails (throws exception or anything) it interrupts the whole download process and other items will not be downloaded. I would want it to continue downloading the rest of the files. I went through the Inno Setup documentation and didn't find any flag which would enable that. Is there a solution for that? Thanks in advance.
A simple solution is to download each file separately.
The below code will allow user to select what to do on each file's download error:
Retry the download
Skip the download
Abort the installation.
var
DownloadPage: TDownloadWizardPage;
function RobustDownload(
Url, BaseName, RequiredSHA256OfFile: String): Boolean;
var
Retry: Boolean;
Answer: Integer;
begin
repeat
try
DownloadPage.Clear;
DownloadPage.Add(Url, BaseName, RequiredSHA256OfFile);
DownloadPage.Download;
Retry := False;
Result := True;
except
if DownloadPage.AbortedByUser then
begin
Log('Aborted by user.')
Result := False;
Retry := False;
end
else
begin
// Make sure the page displays the URL that fails to download
DownloadPage.Msg2Label.Caption := Url;
Answer :=
SuppressibleMsgBox(
AddPeriod(GetExceptionMessage),
mbCriticalError, MB_ABORTRETRYIGNORE, IDABORT);
Retry := (Answer = IDRETRY);
Result := (Answer <> IDABORT);
end;
end;
until not Retry;
end;
function NextButtonClick(CurPageID: Integer): Boolean;
begin
if CurPageID = wpReady then
begin
try
DownloadPage :=
CreateDownloadPage(
SetupMessage(msgWizardPreparing), SetupMessage(msgPreparingDesc),
#OnDownloadProgress);
DownloadPage.Show;
Result :=
RobustDownload('https://example.com/setup1.exe', 'setup1.exe', '') and
RobustDownload('https://example.com/setup2.exe', 'setup2.exe', '') and
RobustDownload('https://example.com/setup3.exe', 'setup3.exe', '');
finally
DownloadPage.Hide;
end;
end
else Result := True;
end;

Inno Setup: duplicated InitializeSetup merge [duplicate]

I use this code to ask for a password:
Inno Setup - Move the password page before the welcome page (first page)
And this code for custom language selector:
Inno Setup - Language selector with VCL Styles
When I merge them, it does not work.
I need password before that the language selector, so this is no correct:
function InitializeSetup(): Boolean;
var
Language: string;
begin
Result := True;
Language := ExpandConstant('{param:LANG}');
if Language = '' then
begin
Log('No language specified, showing language dialog');
SelectLanguage();
Result := False;
Exit;
end
else
begin
Log('Language specified, proceeding with installation');
Result := AskPassword();
end;
end;
And this way, with an incorrect password the setup continues.
function InitializeSetup(): Boolean;
var
Language: string;
begin
Result := True;
Language := ExpandConstant('{param:LANG}');
if Language = '' then
begin
Result := AskPassword();
Log('No language specified, showing language dialog');
SelectLanguage();
Result := False;
Exit;
end
else
begin
Log('Language specified, proceeding with installation');
end;
end;
Inno Setup 6
Inno Setup 6 has event attributes features that helps solving this problem.
Just make sure that each of your event implementation have an unique name, e.g. appending unique suffix. And add event attribute with the name of the implemented event.
[Code]
function InitializeSetup(): Boolean;
begin
Result := ...
end;
<event('InitializeSetup')>
function InitializeSetup2(): Boolean;
begin
Result := ...
end;
Inno Setup 5
In general, the easiest is to keep both implementations of the event function separate and add one wrapper implementation that call both.
function InitializeSetup1(): Boolean;
var
Language: string;
begin
Result := True;
Language := ExpandConstant('{param:LANG}');
if Language = '' then
begin
Log('No language specified, showing language dialog');
SelectLanguage();
Result := False;
Exit;
end
else
begin
Log('Language specified, proceeding with installation');
Result := True;
end;
end;
function InitializeSetup2(): Boolean;
begin
Result := AskPassword();
end;
function InitializeSetup(): Boolean;
begin
{ Order the calls the way you want the checks to be performed }
Result :=
InitializeSetup2() and
InitializeSetup1();
end;
For more general discussion of the problem, see
Merging event function (InitializeWizard) implementations from different sources
Though in your specific case, it's more complicated, as you will also need to pass the password from the first instance to the other, similarly to how the language is passed from the first instance to the other.
So actually, the InitializeSetup2 (password) implementation will have to be similar like the InitializeSetup1 (language), not to ask for the password again.
I actually do not really understand, why you complicate the things so much by not asking for language before the password. It would actually make sense. To get a localized password prompt.

Is it possible in the body of an email to make a link that will launch my Delphi app installed in the local computer?

I m looking for a way to improve the navigation between different tools (under windows). I would like to add in the body of an email a special "link" that when the user will click on it will launch my delphi app installed in his local computer. Is it possible and if yes how to do?
Yes, it is possible. Your application must create a moniker (for example, from its setup or first launch). This will allow the mail client to open an URL pointing to your application, and Windows will launch it and pass the URL to it.
Here is some source code to register/unregister the URL protocol:
function RegisterURLProtocol(
const ProtocolID : String;
const ProtocolName : String;
const DefaultIcon : String;
const OpenCommand : String) : Boolean;
var
Reg : TRegistry;
begin
Result := FALSE;
Reg := TRegistry.Create(KEY_WRITE);
try
Reg.RootKey := HKEY_CLASSES_ROOT;
if not Reg.OpenKey(ProtocolID, TRUE) then
Exit;
Reg.WriteString('', 'URL:' + ProtocolName);
Reg.WriteString('URL Protocol', '');
if Reg.OpenKey('DefaultIcon', True) then begin
Reg.WriteString('', DefaultIcon);
end;
Reg.CloseKey;
if not Reg.OpenKey(ProtocolID + '\shell\open\command', True) then
Exit;
Reg.WriteString('', OpenCommand);
Result := TRUE;
finally
FreeAndNil(Reg);
end;
end;
function UnregisterURLProtocol(
const ProtocolID : String) : Boolean;
var
Reg : TRegistry;
begin
Result := FALSE;
Reg := TRegistry.Create(KEY_WRITE);
try
Reg.RootKey := HKEY_CLASSES_ROOT;
if not Reg.KeyExists(ProtocolID) then
Exit;
Reg.DeleteKey(ProtocolID + '\DefaultIcon');
Reg.DeleteKey(ProtocolID + '\shell\open\command');
Reg.DeleteKey(ProtocolID + '\shell\open');
Reg.DeleteKey(ProtocolID + '\shell');
Reg.DeleteKey(ProtocolID);
Result := TRUE;
finally
FreeAndNil(Reg);
end;
end;
ProtocolID is the identifier for your protocol. You can use something like 'MyApp'. If you had to register the HTTP protocol, you would use 'http'. The application will be opened by Windows when the user clicks on the link. The application will receive what is specified by the OpenCommand (A string you specify). You can include %1 in that OpenCommand and it will be replaced by the URL except the protocol.
ProtocolName is a string describing your protocol.
The URL to place in the mail would be like this:
MyApp://SomeParameters/SomeMoreParameters

Function to load PNG Image from ResourceStream returns nothing

In Delphi 10.1 Berlin, I'm trying to change a picture on a form by loading a PNG image from a resource.
I've followed this:
Load image from embedded resource
and used a TWICImage to automatically handle different possible image formats.
In this case I specifically want to use a PNG for transparency.
For some reason the function I've created returns nothing.
However, if I call result.savetofile('test.png') within the function the resource is succesfully saved, which verifies that the resource exists in the EXE and has been found.
function LoadImageResource(NativeInstance: NativeUInt; ImageResource: string): TWICImage;
var
Strm: TResourceStream;
WICImage: TWICImage;
begin
Strm := TResourceStream.Create(NativeInstance, ImageResource, RT_RCDATA);
try
Strm.Position := 0;
WICImage := TWICImage.Create;
try
WICImage.LoadFromStream(Strm);
result := WICImage; //these return empty
result.savetofile('test.png'); //this succesfully saves the resource to disk
finally
WICImage.Free;
end;
finally
Strm.Free;
end;
end;
Outside of the function, if I attempt to assign the image by calling for example Image1.picture.assign(LoadFromResource(...)) or Image1.picture.graphic := LoadFromResource(...) nothing gets assigned. And If I then call Image1.savetofile('test.png') I get an access violation error.
What might I be missing?
The problem is that you are destroying the image that you return. It's important to understand that classes are reference types in Delphi. So after the assignment to Result, in your code, you still have only a single instance, but two references to that same single instance.
You need to remove the call to Free.
function LoadImageResource(Module: NativeUInt; const ResName: string): TWICImage;
var
Strm: TResourceStream;
begin
Strm := TResourceStream.Create(Module, ResName, RT_RCDATA);
try
Result := TWICImage.Create;
Result.LoadFromStream(Strm);
finally
Strm.Free;
end;
end;
A little tweak is needed to make the function exception safe:
function LoadImageResource(Module: NativeUInt; const ResName: string): TWICImage;
var
Strm: TResourceStream;
begin
Strm := TResourceStream.Create(Module, ResName, RT_RCDATA);
try
Result := TWICImage.Create;
try
Result.LoadFromStream(Strm);
except
Result.Free;
raise;
end;
finally
Strm.Free;
end;
end;
When you call the function it behaves like a constructor. It either succeeds and returns a new instance, handing over ownership to the caller. Or it raises an exception. Accordingly I would name the function CreateImageFromResource.

Load File From Virtual Folder Using Delphi 2007

I am trying to load the contents of a file from one of the Windows virtual folders (for example, a camera or iPhone picture folder). Below is some sample code that I am using to play around with this:
procedure TfrmForm.ButtonClick(Sender: TObject);
Var
Dialog: TAttachDialog;
Enum: IEnumShellItems;
Name: LPWSTR;
Item: IShellItem;
Strm: IStream;
OStrm: TOLEStream;
FStrm: TFileStream;
Result: HRESULT;
Buf: Array[0..99] Of Char;
Read: LongInt;
begin
Result := CoInitializeEx(Nil, COINIT_APARTMENTTHREADED Or
COINIT_DISABLE_OLE1DDE);
If Succeeded(Result) Then
Begin
Dialog := TAttachDialog.Create(Self);
Try
Dialog.Options := [fdoAllowMultiSelect, fdoPathMustExist,
fdoFileMustExist];
Dialog.Title := 'Select Attachments';
If Dialog.Execute(Self.Handle) Then
Begin
If FAILED(Dialog.ShellItems.EnumItems(Enum)) Then
Raise Exception.Create('Could not get the list of files selected.');
While Enum.Next(1, Item, Nil) = S_OK Do
Begin
If (Item.GetDisplayName(SIGDN_NORMALDISPLAY, Name) = S_OK) Then
Begin
mResults.Lines.Add(Name);
CoTaskMemFree(Name);
End;
If Item.BindToHandler(Nil, BHID_Stream, IID_IStream, Strm) = S_OK Then
Begin
OStrm := TOLEStream.Create(Strm);
FStrm := TFileStream.Create('C:\Temp\Test.jpg', fmCreate);
FStrm.CopyFrom(OStrm, OStrm.Size);
FreeAndNil(OStrm);
FreeAndNil(FStrm);
Strm := Nil;
End;
Item := Nil;
End;
End;
Finally
FreeAndNil(Dialog);
End;
CoUninitialize;
End;
end;
TAttachDialog is just a descendant of TCustomFileOpenDialog that exposes the ShellItems property. In my actual application, I need a TStream object returned. So, in this example, I am using a TFileStream top copy the source file as proof of concept that I have successfully accessed the file using a Delphi stream. Everything works Ok until I try the FStrm.CopyFrom at which point I get a "Not Implemented" error. What am I doing wrong with this or is there a better way entirely to do what I want?
The only time TStream itself raises a "not implemented" error is if neither the 32bit or 64bit version of Seek() are overridden in a descendant class (or one of them erroneously called the inherited method). If that were true, an EStreamError exception is raised saying "ClassName.Seek not implemented".
TOLEStream does override the 32bit version of Seek() to call IStream.Seek(). However, it does not override the TStream.GetSize() property getter. So when you are reading the OStrm.Size value before calling CopyFrom(), it calls the default TStream.GetSize() method, which uses Seek() to determine the stream size - Seek() to get the current position, then Seek() again to the end of the stream, saving the result, then Seek() again to go back to the previous position.
So, my guess would be that the IStream you have obtained likely does not support random seeking so its Seek() method is returning E_NOTIMPL, which TOLEStream.Seek() would detect and raise an EOleSysError exception saying "Not implemented".
Try calling IStream.Stat() to get the stream size (or derive a class from TOLEStream and override the GetSize() method to call Stat()), and then pass the returned size to CopyFrom() if > 0 (if you pass Count=0 to CopyFrom(), it will read the source stream's Position and Size properties, thus causing the same Seek() error), eg:
var
...
Stat: STATSTG;
begin
...
if Item.BindToHandler(Nil, BHID_Stream, IID_IStream, Strm) = S_OK Then
try
OStrm := TOLEStream.Create(Strm);
try
FStrm := TFileStream.Create('C:\Temp\Test.jpg', fmCreate);
try
OleCheck(Strm.Stat(Stat, STATFLAG_NONAME));
if Stat.cbSize.QuadPart > 0 then
FStrm.CopyFrom(OStrm, Stat.cbSize.QuadPart);
finally
FreeAndNil(FStrm);
end;
finally
FreeAndNil(OStrm);
end;
finally
Strm := Nil;
end;
...
end;
The alternative would be to simply avoid TStream.CopyFrom() and manually copy the bytes yourself, by allocating a local buffer and then calling OStrm.Read() in a loop, writing each read buffer to FStrm, until OStrm.Read() reports that there is no more bytes to read:
var
...
Buf: array[0..1023] of Byte;
NumRead: Integer;
begin
...
if Item.BindToHandler(Nil, BHID_Stream, IID_IStream, Strm) = S_OK Then
try
OStrm := TOLEStream.Create(Strm);
try
FStrm := TFileStream.Create('C:\Temp\Test.jpg', fmCreate);
try
repeat
NumRead := OStrm.Read(Buf[0], SizeOf(Buf));
if NumRead <= 0 then Break;
FStrm.WriteBuffer(Buf[0], NumRead);
until False;
finally
FreeAndNil(FStrm);
end;
finally
FreeAndNil(OStrm);
end;
finally
Strm := Nil;
end;
...
end;

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