The Dmd2.030 spec. said:

static Object factory(string classname); Create instance of class specified by classname. The class must either have no constructors or have a default constructor.

and said also:
class ClassInfo
static ClassInfo find(in char[] classname);
Search all modules for ClassInfo corresponding to classname.

Returns:
null if not found

Object create(); Create instance of Object represented by 'this'.

In below code snippet:

class Dog
{
public void bark(){}
}
int main(string[] args)
{
auto obj=Object.factory("Dog");
Dog doggie=cast(Dog)obj;
doggie.bark;

return 0;
}

Compiled successfully but failed when run: Object.Error:Access Violation.

I also tried ClassInfo.find(string classname),ClassInfo.create() but caused the same error.

In the above code snippet,if I wrote as below:
class Dog{...}
int main(string[] args)
{
Object obj=Object.factory("Dog");
obj=new Dog;   //1
Dog doggie=cast(Dog)obj;//2
doggie.bark;

return 0;
}
Everything works fine.But it seems that this does not make sense to dynamic create class instance.It is just the same as below:
Object obj;
obj=new Dog;
(cast(Dog)obj).bark;

So is there any other options can I reach the goal,i.e.,dynamically create an class instance and invoke its method?

Thanks in advance.

Regards,
Sam

Sam Hu Wrote:

> The Dmd2.030 spec. said:
> 
> static Object factory(string classname); Create instance of class specified by classname. The class must either have no constructors or have a default constructor.
> 
> and said also:
> class ClassInfo
> static ClassInfo find(in char[] classname);
> Search all modules for ClassInfo corresponding to classname.
> 
> Returns:
> null if not found
> 
> Object create(); Create instance of Object represented by 'this'.
> 
> In below code snippet:
> 
> class Dog
> {
> public void bark(){}
> }
> int main(string[] args)
> {
> auto obj=Object.factory("Dog");
> Dog doggie=cast(Dog)obj;
> doggie.bark;
> 
> return 0;
> }
> 
> Compiled successfully but failed when run: Object.Error:Access Violation.
> 
> I also tried ClassInfo.find(string classname),ClassInfo.create() but caused the same error.
> 
> In the above code snippet,if I wrote as below:
> class Dog{...}
> int main(string[] args)
> {
> Object obj=Object.factory("Dog");
> obj=new Dog;   //1
> Dog doggie=cast(Dog)obj;//2
> doggie.bark;
> 
> return 0;
> }
> Everything works fine.But it seems that this does not make sense to dynamic create class instance.It is just the same as below:
> Object obj;
> obj=new Dog;
> (cast(Dog)obj).bark;
> 
> So is there any other options can I reach the goal,i.e.,dynamically create an class instance and invoke its method?
> 
> Thanks in advance.
> 
> Regards,
> Sam
> 
> 
BTW,why __traits has no isStaticFunction?
Thanks in advance.

Sam Hu Wrote:

> 
> In below code snippet:
> 
> class Dog
> {
> public void bark(){}
> }
> int main(string[] args)
> {
> auto obj=Object.factory("Dog");
> Dog doggie=cast(Dog)obj;
> doggie.bark;
> 
> return 0;
> }
> 
> Compiled successfully but failed when run: Object.Error:Access Violation.
> 
> I also tried ClassInfo.find(string classname),ClassInfo.create() but caused the same error.
> 

Object.factory requires a fully qualified class name, so if class Dog resides in module animals, call Object.factory("animals.Dog").

John C Wrote:

> Object.factory requires a fully qualified class name, so if class Dog resides in module animals, call Object.factory("animals.Dog").

It works now.Great!Thanks so much!

But...may I ask how do you know that?(requires full name).I went through the object.di but nothing relative found.

Sam Hu escribió:
> John C Wrote:
> 
>> Object.factory requires a fully qualified class name, so if class Dog resides in module animals, call Object.factory("animals.Dog").
> 
> It works now.Great!Thanks so much!
> 
> But...may I ask how do you know that?(requires full name).I went through the object.di but nothing relative found.

There: http://d.puremagic.com/issues/show_bug.cgi?id=3093

Ary Borenszweig Wrote:

> Sam Hu escribi?
> > John C Wrote:
> > 
> >> Object.factory requires a fully qualified class name, so if class Dog resides in module animals, call Object.factory("animals.Dog").
> > 
> > It works now.Great!Thanks so much!
> > 
> > But...may I ask how do you know that?(requires full name).I went through the object.di but nothing relative found.
> 
> There: http://d.puremagic.com/issues/show_bug.cgi?id=3093

Thanks a lot.

I found the reflection(object module + __traits) of the current version of D2 is very powerful already .Wondering how come some ppl here felt that D is still lack of reflection?

Sam Hu Wrote:

> John C Wrote:
> 
> > Object.factory requires a fully qualified class name, so if class Dog resides in module animals, call Object.factory("animals.Dog").
> 
> It works now.Great!Thanks so much!
> 
> But...may I ask how do you know that?(requires full name).I went through the object.di but nothing relative found.
> 

Common sense, to be honest.