Application deployment with assistant as help viewer

**jml** · 13th August 2008, 23:04

I am using assistant as a custom help viewer for my application, and it works fine on my machine with Qt installed. But I can't find anything in the Qt documentation about how to deploy asistant along with my application and my .qhc file to another target machine. Thanks for any help.

**jml** · 14th August 2008, 18:40

I managed to get assistant with all its dependencies to run on the target machine. EXCEPT, it now gives me the error message

"The specified collection file coud not be read!"

with no additional information.

I should say that I'm developing on Windows/XP, VS2005 with Qt 4.4.1 commercial addition.

If, on the target machine, I do this from the command prompt

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assistant -collectionFile foo.qhc

assistant -collectionFile foo.qhc

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I get the above error message. The very same help collection file works fine on my development machine.

Due to the under-whelming response to my initial post, I have no great expectations for any help here on this forum. But it is very frustrating that the QT documentation touts this new and improved assistant as a custom help tool, but says absolutely nothing about how to deploy it to a target machine, and evidently the QT employee(s) who monitor these forums have no knowledge either.

**jacek** · 14th August 2008, 20:17

Originally Posted by jml

evidently the QT employee(s) who monitor these forums have no knowledge either.

Qt Centre is not "monitored" by any company employees. It is run solely by volunteers. If you want help from Nokia's Qt Software division, contact the support.

**jml** · 27th August 2008, 21:05

Well, after much conversation with Qt support, and my own sleuthing, I finally got my application to deploy successfully with assistant as a custom help viewer. For anyone interested, you need to know:

1. The help collection file (.qhc) is an sqlite database. You need to ship
%QTDIR%/plugins/sqldrivers/qsqlite4.dll with your application, AND it must be in the subdirectory sqldrivers. As far as the subdirectory goes, maybe it's possible to change that with qt.conf, but I don't know how.

2. It was my impression the .qhc file had everything needed for deployment, though I don't think the QtHelp documentation says explicitly. But you also need to ship the .qch files - the intermediate files that are the output from qhelpgenerator and the input to qcollectiongenerator.

I hope this saves someone the grief that I went through to get this to work. My impression is that QtHelp, being a new feature in Qt, isn't quite ready for prime time - at least the documentation of it isn't. Hopefully that will change in future releases.

**jml** · 30th December 2008, 18:22

Well, I've since upgraded to Qt4.4.2, and the advice in my previous post no longer works. The assistant simply exits with no error message and does nothing.

.

For all those who are considering using assistant as a custom stand-alone help viewer for applications, I have this word of advice: DON'T!!!.

I'm very disappointed in Qt for documenting this as an option but not supporting it. I wish I had not gone down this path.

**wysota** · 31st December 2008, 17:08

As far as I know this works quite fine so you must be having some deployment problems. Is your Qt taken from some binary package distribution or did you compile it yourself? What exactly happens, have you tried debugging?

**jml** · 2nd January 2009, 18:20

I'm using a binary distribution - I did not compile it myself.

I'm not sure how I would go about debugging it. It's the application.exe that is not functioning - not my application.

I have two versions of my application deployed on my machine - the same one I'm developing on running Vista, developing with Visual Studio 2005. I'm running the assistant from the command line (cygwin). Version 1 of my application was built using Qt 4.1.x, version 2 was built using Qt 4.4.2

In the command line, if I go to C:\Program Files\myAppVersion1 and run
> ./assistant -collectionFile myHelp.qhc
it brings up the assistant with my help files just fine.

But, if I set my current directory to C:\Program Files\myAppVersion2 and enter the same command, it returns to the command prompt and nothing happens.

In both directories, if I leave out the "./" so that it runs the installed assistant in
C:\Qt\4.4.2\bin, it works fine. I actually copied every .dll file from c:\Q\4.4.2\bin into the deployment directory under "Program Files" and still nothing happens.

**wysota** · 2nd January 2009, 18:52

Originally Posted by jml

I'm not sure how I would go about debugging it. It's the application.exe that is not functioning - not my application.

We usually debug executable files

Try running assistant under gdb (or whatever other debugger you use) and when it crashes (it crashes, right?), check the backtrace to see where it crashes. Just make sure you are using a debug-enabled version of assistant.

But, if I set my current directory to C:\Program Files\myAppVersion2 and enter the same command, it returns to the command prompt and nothing happens.

Maybe it simply can't find the help collection file?

In both directories, if I leave out the "./" so that it runs the installed assistant in
C:\Qt\4.4.2\bin, it works fine. I actually copied every .dll file from c:\Q\4.4.2\bin into the deployment directory under "Program Files" and still nothing happens.

Did you copy the sqlite driver to the sqldrivers subdirectory of the directory Qt searches for plugins (like the current directory or any directory defined in qt.conf file)? Does assistant work if you tell it to use one of the default help collections?

**jml** · 2nd January 2009, 19:06