Folks, Sorry for the big e-mail. If your time is short, I guess the item 4 is the one I would love some expertise.
So, I have implemented a few things and I would love to hear your feedback to see if I'm going in the right way. A little explanation about everything: - grl-lua-factory.c: load/remove lua-plugins, get the operations from application and pass it to lua-pluging; - grl-lua-library.c: This is a module to lua-plugins. There are two functions implemented: callback and fetch; - grl-metrolyrics.lua: The plugin which I'm using to develop both glue-codes above. The code is here: https://github.com/victortoso/grilo-plugins [on master] 1-) I'm using lua version 5.2.2 in this project. Why ? Is the most recent one but looks like it is one year old already. 2-) Using a table to set the plugin [0]. I really thought that this was the easiest way possible. e.g. The developer has to set plugin.search = "function_name" and this would be the handler of Search operation. [0] https://github.com/victortoso/grilo-plugins/blob/master/src/lua-factory/sources/grl-metrolyrics.lua#L27 3-) I was afraid about implementing async functions in lua-library but it worked as in pure c (in the fetch function). I'm just pointing this because I felt that is important to show that async functions works fine in the glue-code. 4-) Building the Media. Currently, I'm using in lua the string 'GRL_METADATA_KEY_ARTIST' to set the artist name. I like this as a good way to keep the standards. The lua-library function that will build the media verify each string and use the right function to set the media. This is a bit of overwork, but I don't know a better way. Actually I thought about setting the defines to be used with grilo module [1] but it doesn't feel the right approach. Opinions on this ? [1] http://lua-users.org/lists/lua-l/2001-01/msg00156.html 5-) Userdata problem - case: The lua-factory request to lua-plugin to execute a Search. when the lua-plugin has the Media ready, it'll call the grilo.callback. This function needs to know the application-callback function and the plugin source. Currently I'm passing a c pointer to lua-plugin (as userdata) and passing it to the callback. It is always a pointer to struct OperationSpec. I'll change this in order to not pass a struct without meaning to lua. I intend to register this structure from lua-factory in lua-library right before passing the control to the lua-plugin. To grilo.callback know which structure this operation is from, it need some key. I intent to use the operation_id. So, instead of userdata, I'll pass the operation id, which will be used to get the right structure in the callback. I guess this is it. This week I intend to finish the item 5 and improve the item 4 as I've done only what grl-metrolyrics needs. The Browse, Query and Resolve operation are almost ready to go too. After this, my idea is to write a new plugin, which I can use some configs to set-up and others operations that Metrolyrics does not provide. best regards, _______________________________________________ grilo-list mailing list grilo-list@gnome.org https://mail.gnome.org/mailman/listinfo/grilo-list
