Wt

Hello,

I am new to c and Wt but have been able to work through many of the examples and even created some of my own basic applications using code snippets from the wt examples.

The issue that I am having is that I cannot get the wt::dbo::QueryModel to work with WTableView. I am using wt 4.0.3. where setting the model on tableview has changed from Wt 3.3.10

#include <Wt/WTableView.h>

void Wt::WTableView::setModel (const std::shared_ptr< WAbstractItemModel > & model )

I was able to create an example using both WStandardItemModel and WStringListModel and both worked without issue. But when I tried to expand on the examples by connecting to MySql, things do not go so well.

// Using Wt::Dbo::QueryModel

auto dUser1 = std::make_shared<Wt::Dbo::QueryModel<Wt::Dbo::ptr>>();

dUser1->setQuery(session.find());

dUser1->addAllFieldsAsColumns();

// I validated that dUser1 is connecting to db and executing query by sending results to std::cerr

const auto dUser1 = std::make_shared<Wt::Dbo::QueryModel<Wt::Dbo::ptr>>();

dUser1->setQuery(session.find());

dUser1->addAllFieldsAsColumns();

for (int row = 0; row < dUser1->rowCount(); ++row) {

for (int column = 0; column < dUser1->columnCount(); ++column) {

auto aItem = std::make_uniqueWt::WStandardItem();

aItem->setText("Item " + std::to_string(row)

• ", " + std::to_string(column));
  aModel->setItem(row, column, std::move(aItem));
  }
  }

//Finally, I added the tableview set some of the attributes and applied the model;

auto tv = root()->addWidget(Wt::cpp14::make_uniqueWt::WTableView());

tv->setAlternatingRowColors(false);

tv->setColumnResizeEnabled(false);

tv->setSelectionMode(SelectionMode::Single);

//The failure occurs whenever I try to apply the query model to the tableview;

tv->setModel(dUser1); // This causes the page/server to crash !!!

The code compiles, but the server crashes whenever I hit the webpage. What I mean by crash is that I get a core dump. Any help would be appreciated.

Thanks!

PD