Hi Koen.
> What we usually do is store this information in the specialized
> WApplication object,
> and then provide a static method MyApplication::instance() which
> returns this MyApplication *object like this:
>
> MyAppliation *MyApplication::instance() {
> return dynamic_cast<WApplication *>(WApplication::instance());
> }
>
> (Internally, WApplication::instance() does indeed use thread specific
> storage to store the session that is bound to the current thread. Note
> that this may change arbitrarily between events).
>
> In this way you could write:
>
> MyWidget::foo() {
> Memcache mc(MyApplication::instance()->mc_pool());
> std::string val = mc.get("my_key");
> // Do something with val and mc is automatically returned to the pool
> }
>
> without needing to store information in the widgets.
>
> Would this approach not meet your needs ?
Almost. What I'd like is the following:
void MyApp::foo() {
MyApp::instance()->req_resource<soci_conn> = MyApp::instance()-
>soci_conn();
soci::session *sql = MyApp::instance()->req_resource<soci_conn>;
sql.begin();
MyModel obj;
obj.do_something();
sql.commit();
}
and in MyModel:
void MyModel::do_something() {
soci::session *sql = MyApp::instance()->req_resounrce<soci_conn>;
sql << "SELECT foo, bar FROM baz", into(foo_), into(bar_);
}
Because of the call to begin()/commit(), it is very important that I
preserve the exact same SQL session as I descend from the controller
to the model. Because of the state-hiding nature of Wt, I don't know
how to ensure that my database connection gets handed back to the
connection pool at the end of the HTTP request. Thoughts on how best
to achieve this? -sc
PS: For the sake of providing a complete example for the search
engines in the future, here's a reasonably complete example for
someone else to follow (note the correction in dynamic_cast):
#include "MyRes"
class MyApp : public Wt::WApplication {
public:
MyApp(MyRes& res, const Wt::WEnvironment& env) :
Wt::WEnvironment(env), res_(res) {}
MyRes& res() const { return res_; }
static MyApp *instance() { return dynamic_cast<MyApp
*>(Wt::WApplication::instance()); }
private:
MyRes& res_;
};
void MyWidget::some_func() {
MyRes r(MyApp::instance()->res());
r.foo();
}
--
Sean Chittenden
[email protected]
------------------------------------------------------------------------------
Enter the BlackBerry Developer Challenge
This is your chance to win up to $100,000 in prizes! For a limited time,
vendors submitting new applications to BlackBerry App World(TM) will have
the opportunity to enter the BlackBerry Developer Challenge. See full prize
details at: http://p.sf.net/sfu/blackberry
_______________________________________________
witty-interest mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/witty-interest
