Kees Jongenburger wrote: > On 5/2/05, Michiel Meeuwissen <[EMAIL PROTECTED]> wrote: > > The 'checksum' field would be on the 'images' node, which provides you with > > some way to check if the same image was uploaded already. It is imaginable > > that a person forgot about wether a certain image was uploaded > > already or not. > Who is supposed to set the cheksum then? and what message can you say > "you already uploaded the exact same image" , did you have enough coffe today?
The checksum is set by MMBase. For example when you set the handle-field or on commit of the node. > > In other words this check-sum could be used to search by the > > byte-array. It could also be used for automatic synchronization of a batch > > of images (e.g. from a digital camera), and avoid duplicates. One could also > > try to do this by file-name, but that is less absolute. > Yes this is possible , but in that case you want to have something > that is more generic > something like syncnodes. I'd say that it's better to have good > working async convertion > and make it possible to extend images or have "image" fields Still, for comparison of blob-data you probably don't want to use the blob itself. If we would implement it by a plug-in using the 'fieldtypes' framework, it would logically be possible to define a field as a checksum of another field, and this functionality would then be completely generic. That would of course be my goal, but otherwwise it would be very simple to do something more ad hoc somewhere in the image-code. This would also be valid for the other fields like 'filesize' 'itype' 'height' and 'width'. Those are now implemented ad hoc in Images,supposing a 'handle' field. That is no big problem, but evuentually it would be possible to move that stuff to field-implemntations too, and then you dont' need the image-builder any more, but can have anything on 'field' level. That would be nice, but hardly essential for the moment, and I consider it a implementation detail. Michiel -- Michiel Meeuwissen mihxil' Mediacentrum 140 H'sum [] () +31 (0)35 6772979 nl_NL eo_XX en_US _______________________________________________ Developers mailing list [email protected] http://lists.mmbase.org/mailman/listinfo/developers
