Re: Charsets, Gtkmm and MySQL

[Bernd Robertz <bernd robertz cssweb de>]

Thanks alot for your fast reply,

I wrote a simple MySQL-Class wich is derived from the libsql++ class.

In this class I used std::string to get the columns of a row.
The columns (strings) are stored in a vector<string> wich I return to
Glib::ustring in My treeview-data-window.

Hiere are some snippets:

:::::::::::::::::::::::: SNIP ::::::::::::::::::::::
database.cpp
(My simple MySQL database class.)

DataBase::Database()
{
	// db-connect
	// query-setup
	// other connect related stuff

	mysqlpp::StoreQueryResult result; // Setup the result object
	int rows; // Keep track of result counts
}

void DataBase::returnrow(int dataid)
{
	// Setup db-query with dataid to get requested db-row
	//
	mysqlpp::Query query = dbcon.query(queries.alldata); // DB Query
	result = query.store(); // Store the results
	rows = result.num_rows(); // Set the number of results
}

std::vector<std::string> DataBase::fetchdata(int row)
{
	std::vector<std::string> tmp; // Temp vector for return
	
	for (int i = 0; i < result.field_names()->size(); ++i)
	{
		// Every column will be stored in the temp vector
		tmp.push_back((std::string)result[row][i]);
	}
	return tmp; // Return the temp-vector with the [columns]=data
}

------------

datawindow.cpp
(The window in where the data is displayed after dbl-click on treeview)

DataWindow::DataWindow()
{
	// Widgets setup
	// Database connect via DataBase-Object
}

void DataWindow::getid(int dataid)
{
	// From the treeview I call this method to set the
	// requested row-id
	mysql.returnrow(dataid);

	// Call this method to setup the entries and textview
	setdata();
}

void DataWindow::setdata()
{
	l_dataid.set_text(mysql.fetchdata(0)[0]);
	Gtk::TreeModel::Row selrow = *(ls_cbox->prepend());
	selrow[c_mod.c_cat] = mysql.fetchdata(0)[1];
	cbox.set_active(0);

	// Here comes the problem, I get every column from My
	// database-object wich I store in the entries.
	e_name.set_text(mysql.fetchdata(0)[2]);
	e_number.set_text(mysql.fetchdata(0)[3]);
	e_user.set_text(mysql.fetchdata(0)[4]);
	e_pass.set_text(mysql.fetchdata(0)[5]);
	e_mail.set_text(mysql.fetchdata(0)[6]);
	e_url.set_text(mysql.fetchdata(0)[7]);
	e_other.set_text(mysql.fetchdata(0)[8]);

	// Here we have the main problem: the textview-buffer
	// Some rows are shown here, some not.
	b_descr->set_text(mysql.fetchdata(0)[9]);
}

::::::::::::::::::::::::: SNIP END ::::::::::::::::::::::::::::

That is the main code where the problem occours.

The DataWindow is called on doubleclick on a treeview-row.
With the call of the DataWindow I call the DataView::getid()
wich receive the database row-id.
Then I fill with the DataView::setdata() method the widgets
in the new window.

Some chars are, as I told, glyphs, but the textbuffer is the main
problem.

As far as I know, the entries and textbuffers are expecting
Glib::ustring, but I thought the conversion from std::string to
Glib::ustring is quite compatible between these types.
I used std::string in the database class, because I wanted to isolated
it from Gtkmm for other not Gtkmm-related projects.

Thank you for helping.

Bernd


Am Sonntag, den 28.12.2008, 22:26 +0100 schrieb Milosz Derezynski:
> Are you using Glib::ustring anywhere in the process of getting the
> data from the SQL database to the view?
> 
> Glib::ustring implicitly (and in my opinion still at least not well
> enough documented/hinted at) converts from UTF-8
> to the current locale with operators << and >>. If you are using a
> stringstream anywhere in the process, or are 
> using operator<< or operator>> in any other way, this could then be
> the cause of the problem.
> 
> Otherwise, and in the above described case too actually it would help
> very much if you could post (if possible, all of)
> the relevant code online.
> 
> Regards,
> M.
> 
> On Sun, Dec 28, 2008 at 8:53 PM, Bernd Robertz
> <bernd robertz cssweb de> wrote:
>         Hello list,
>         
>         I'm not really sure, but I hope My question is in the right
>         place here.
>         
>         I wrote a simple database app like this:
>         
>         Connect to a MySQL server via libmysql++,
>         and then list the rows in a treeview.
>         Doubleclick on a row shows a window with some entries and a
>         textview
>         with the content of the selected row.
>         The textview is associated with a type text in the DB.
>         
>         Everything is fine.
>         
>         So but I ran really into problems with the charsets.
>         german umlaute (ö, ä, etc.) and some other characters are
>         glyphs in the
>         treeview. Ok, thats not the main problem.
>         
>         That is: The entries in the detailed view still shows the
>         glyphs for
>         some chars like ö, ä.
>         But on some rows, the represented textbuffer for textview is
>         not
>         visible. Wich means the textview is in some rows empty.
>         
>         I run My app from a console and I got these error messages:
>         
>         :::::::::
>         Gtk-CRITICAL **: gtk_text_buffer_emit_insert: assertion
>         `g_utf8_validate
>         (text, len, NULL)' failed
>         :::::::::
>         
>         In other rows, the textbuffer is correct shown, exepct some
>         glyphs.
>         
>         If I print the textbuffer as a simple .c_str() in a console it
>         will be
>         shown correctly (inklusive ä, ö, ü...).
>         (Tried to show the textview as a .c_str(), without any
>         effect.)
>         
>         The SQL connection is serverside-configured as UTF-8 Unicode.
>         The SQL table collation is UTF-8 General CI (Case
>         Insensitive).
>         The Application runs on a DE_de Euro (ISO-8859-15).
>         
>         All characters are shown correctly in a PHP app wich does the
>         same, just
>         only online. :-)
>         
>         I hope someone could turn on a light above my head, why I
>         don't get the
>         right charactes.
>         
>         Thanks alot in advance
>         
>         Bernd
>         
>         
>         _______________________________________________
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>         http://mail.gnome.org/mailman/listinfo/gtkmm-list
> 
> 
> 
> -- 
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