If a method creates an object ($no:=new object), the object is destroyed when the method ends? and if a method creates a new shared object ($nso:=new shared object), the object continues to exist after the method ends, but the reference to it is lost? Does 4D know to clear the object in this case?
Keith - CDI > On Oct 20, 2018, at 11:28 PM, Keisuke Miyako via 4D_Tech > <[email protected]> wrote: > > I prefer to explain it this way: > > when you pass a New object or New collection to a method (subroutine), > that object or collection is shared between the 2 methods, caller and callee, > because they are running in the same process. > > if you execute $1.foo:="bar" in the callee, > the object from the caller is also updated, > because they are in fact referenced to the same object. > > if you do the same across processes, > i.e. pass a New object or New collection to New process, CALL WORKER or CALL > FORM, > the object or collection is not shared between the 2 methods, caller and > callee, > because they are not running in the same process. > > the best way to share an object or collection between processes is to pass a > shared object or shared collection as a parameter. > there is no need to use Storage, there is no need to use interprocess > variables. > you just create a shared object or shared collection, and pass it as an > argument to another process or worker. > the received object is not a copy, it is a shared reference to the same > shared object. > > Storage is not mandatory, if you always pass shared objects using parameters, > which is good practice, according the law of Demeter. > > https://en.wikipedia.org/wiki/Law_of_Demeter > > the reason why Storage often pops up in the context of interprocess variables, > is because we recognise that in many applications, interprocess variables are > casually references all over the place. > it is provided as a last resort, a global shared object to which you can > attach all your shared objects > so that you can access them from anywhere in your code, without using > parameters. > >> 2018/10/21 13:11、lists via 4D_Tech <[email protected]>のメール: >> >> In order to share an object between processes without using an interprocess >> variable, you must use the "Storage" container/catalog. > > > > > ********************************************************************** > 4D Internet Users Group (4D iNUG) > Archive: http://lists.4d.com/archives.html > Options: https://lists.4d.com/mailman/options/4d_tech > Unsub: mailto:[email protected] > ********************************************************************** ********************************************************************** 4D Internet Users Group (4D iNUG) Archive: http://lists.4d.com/archives.html Options: https://lists.4d.com/mailman/options/4d_tech Unsub: mailto:[email protected] **********************************************************************
