Hi,
I have problems reading a single object from a Chain, something which
works for a normal file:
TChain chain("Tree", "My Tree");
chain.Add("file.root");
TObject *o=chain.GetFile()->Get("MyObject");
does not work, because chain.GetFile() returns a null pointer unless one
has at least connected to a branch on the file, first (which I use as a
Workaround), while the following works allways:
TFile f("file.root");
TObject *o=f.Get("MyObject");
Is this is a design limitation, or a bug?
My personal conviction is, that it is probably a bug, because already
connecting to a branch makes chain.GetFile() return the first file, while
a design limitiation would probably require you to use GetEntry() on the
chain, first.
My request is therefore to have TChain::GetFile() return the first file in
the chain as soon as there is one added, or, implement a Get() method on
the TChain.
Cheers,
Birger
--
Birger Koblitz Tel: +33/1 69 33 31 73
Ecole Polytechnique - LLR
Route de Saclay
F-91128 Palaiseau
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