----- Original Message ----- > From: Michael Van Canneyt <mich...@freepascal.org> > To: FPC-Pascal users discussions <fpc-pascal@lists.freepascal.org> > Cc: Lazarus mailing list <laza...@lazarus.freepascal.org> > Sent: Friday, December 16, 2011 2:53 PM > Subject: Re: [fpc-pascal] JSON Dataset in FCL-DB. > > > > On Fri, 16 Dec 2011, Leonardo M. Ramé wrote: > >> From: Michael Van Canneyt <mich...@freepascal.org> >>> To: FPC mailing list <fpc-pascal@lists.freepascal.org>; Lazarus > mailing list <laza...@lazarus.freepascal.org> >>> Sent: Friday, December 16, 2011 1:37 PM >>> Subject: [fpc-pascal] JSON Dataset in FCL-DB. >>> >>> >>> Hello, >>> >>> I just committed a JSON dataset in fcl-db. >>> >>> This is a dataset which stores its data in JSON objects (as in fpjson) > in memory. The records are in a JSON array, each record can be a JSON object > or > array. >>> (not mixed) >>> >>> The dataset is read-write. It can be used to create JSON data from > scratch: just add definitions to the fielddefs properties, and call > 'Open'. At the end, call SaveToStream(). >>> >>> There are 2 descendents which read/write ExtJS JSON data packages > (Objects or Arrays) from streams but they are usable to handle any kind of > JSON > data. Currently, the dataset does not yet support propagating changes > (deltas) > back to a server. >>> >>> I would be glad to recieve feedback, comments. >>> >>> Michael. >> >> >> >> Does this allow executing selects against an sql database and traverse the > results using this JSON dataset? > > Yes. I use it as follows: > > Normally, Fcl-web server using the sql-db and fpwebdata sends JSON-Formatted > data to a browser. > > I have now a lazarus-written client app which sends a HTTP request to the > same > webserver, > reads the returned JSON, and then opens a dataset with the JSON as source of > the > data. > > Combined with the Ext.Direct RPC, I intend to use this for N-tier apps where > the > client > can be a native app or a browser. > > What is missing currently is the delta to update data on the server, but that > should be easily added. > > Michael.
Thanks. Btw. I've found this dependency related error when I tried to compile. ... PPU Loading /usr/local/lib/fpc/2.7.1/units/x86_64-linux/fcl-web/fpwebdata.ppu Recompiling fpwebdata, checksum changed for db Fatal: Can't find unit fpwebdata used by fpjsondataset ... -- Leonardo M. Ramé http://leonardorame.blogspot.com _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
