On Mon, Apr 13, 2009 at 2:11 PM, mdipierro <[email protected]> wrote:
> > I agree that the syntax you propose is cleaner but why are we doing > this? > > For me the reason is move functionality out of T3. Ok. > In particular we need a way to store a model in another model (think > of a table of table descriptions) in order to be able to create models > on GAE without going through the local development environment. The > shorthand notation for me is just a bonus. > > Having the entire table represented as a single string accomplishes > this: > > for table in db(db.meta.id>0).select(): db.define_table > (table.shorthand) Ok - but you are still talking higher level functionality here (single string); What do you loose from this: for table in db(db.meta.id>0).select(): db.define_table(table.shorthand()) Nothing - it's just a matter of how much you push down into the core. Putting _too_ much higher level assumptions low just blocks other, similar (or unanticipated) uses. ['table_name', 'field_name:field_type:field default'] ==> "table_name; field_name:field_type:field default;" Put another way, you are pushing a particular persistent storage issue down into gluon (wanting a single string) - I question this. There are numerous ways to store, so being explicit about what _kinds_ of uses you are targetting is important. You have stated one (and until now, at least on this thread and in the code, it has been implicit; it's good to make it explicit). In any case, if you intend to write a single blob, it would be good exercise to implement a parser, and then think about where each piece belongs. (this actually looked interesting, as I scanned for parser generators: http://www.acooke.org/lepl/) <http://www.acooke.org/lepl/> > > Massimo > > > On Apr 13, 1:59 pm, Yarko Tymciurak <[email protected]> wrote: > > On Mon, Apr 13, 2009 at 1:53 PM, Yarko Tymciurak <[email protected]> > wrote: > > > On Mon, Apr 13, 2009 at 1:40 PM, Yarko Tymciurak <[email protected] > >wrote: > > > > >> I have a couple of immediate comments: > > >> [1] - with this syntax, you do not process and fields or migrate > > >> statements (but you _could_; suggest you do) > > >> [2] - the autofields() function seems to mash concerns in other ways > also: > > >> it handles tablename update (? why here) in addition to "autofields"; > for > > >> one thing, it does NOT do cleanup() (as define_table otherwise does) - > this > > >> is the beginnings of handling things differently in different > conditions > > >> (and a typical symptom of blurred boundaries of concerns). > > > > >> Suggest you DO table name handling in _one place_, and field > processing > > >> (as you have) in one place, and consider that you only ADD > "autofields" as a > > >> new syntax for defining fields. > > > > >> Having said that, it occurs to me that a comma separated text string > is > > >> just one layer of this, and it would be good to split this out, so > that > > >> web2py application developers could create things more automatically, > to > > >> wit: > > > > >> [3] in sql.autofields() ==> for field in fields.split(',') ---- I > would > > >> make this do NO MORE than call an individual field processing function > > >> (separate this functionality) > > > > >> [4] I would add / allow a list to be passed (that is, allow the > > >> application developer to _already_ have split the field definitions to > "the > > >> new text specification format") --- this will be much handier for > automated > > >> processing. There are a couple of ways you could handle this, one > being > > >> parsing *fields in define_table() to first split them out to string > (or > > >> list?) vs. function types, process all the string types by some > > >> autofields_parse() function, collect and pass the rest to > SQLTable(self, > > >> tablename, *fields)... > > > > > ... as I think of this, and of application developers I would ONLY > process > > > lists for the "new" syntax - there is no useful reason to have a string > that > > > the CORE then splits on ',' and only complicates the core.... this is > the > > > kind of niceity that better belongs at the application level - either > for > > > the app writer, or in an admin (or other higher level function). > > > > > So I now would prefer to see *fields argument to define_table() > handle > > > all field definitions, and based on type of ...field in fields'... I > would > > > collect them and process accordingly. If you _really_ want, you could > > > insist that the fields list passed to define table be already coalesced > > > (this would simplify core) - that is, all of one together, so that a > change > > > is assumed to apply to rest of fields (I think this is prefectly > > > reasonable).... > > > > > So you see what I am proposing, I would do something like: > > > > > db.define_table('mytable', > > > 'name', > > > 'birthday date', > > > SQLField( 'some_other_field', 'integer', default=foo()), > > > # and all the following are now assumed to be function calls > > > ) > > > > > or, alternatively: > > > > > dyna_fields= ['name', 'birthday date'] > > > > Note this also can free up other things: ":" can now be a separator (so > > spaces in validators can be used), e.g.: > > > > dyna_fields=['name', 'birthday: date', 'some_comment: text: default > string'] > > > > I think this opens the possibility for more "regular" processing, and > > broader ways of generating tables. > > > > What do you think? > > > > - Yarko (... still thinking about this...) > > > > db.define_table('mytable, *dyna_fields, > > > > > SQLField( # and so forth....) > > > ) > > > > > - Yarko > > > > >> Make sense? I think with a little finesse this could provide more > than a > > >> "nice syntax", rather a handy way to automatically generate tables > from > > >> descriptors. > > > > >> Regards, > > >> - Yarko > > > > >> 2009/4/13 mdipierro <[email protected]> > > > > >>> Try latest trunk. You can do: > > > > >>> db.define_table('friendship: person by name birthday notnull, dog by > > >>> name ') > > > > >>> mind that you cannot have both notnull and unique and you cannot have > > >>> a unique reference because I just realized we lack a validator to do > > >>> it. I will make one and extend this.. > > > > >>> Massimo > > > > >>> On Apr 13, 12:26 pm, mdipierro <[email protected]> wrote: > > >>> > Actually it does just > > > > >>> > db.define_table('friendship' > > >>> > ,SQLField('person_name') > > >>> > ) > > > > >>> > but I am about to follow your suggestion (with a slight change in > > >>> > notation) and do > > > > >>> > db.define_table('friendship: person by name birthday notnull, dog > by > > >>> > name ') > > > > >>> > generate: > > > > >>> > db.define_table('friendship' > > >>> > ,SQLField('person',requires=IS_IN_DB(db,'person.id','%(name) % > > >>> > (birthday)',notnull = True), > > >>> > ,SQLField('dog',requires=IS_NULL_OR(IS_IN_DB(db,'dog.id','% > > >>> > (name)')), > > >>> > ) > > > > >>> > Massimo > > > > >>> > On Apr 13, 11:13 am, DenesL <[email protected]> wrote: > > > > >>> > > Maybe too short to be useful, but when you get to references it > would > > >>> > > be nice to have: > > > > >>> > > db.define_table('friendship: person.name, dog.name') > > > > >>> > > But then, does this mean: > > > > >>> > > db.define_table('friendship' > > >>> > > ,SQLField('person_name' > > >>> > > ,db.person > > >>> > > ,requires=IS_IN_DB(db,db.person,'%(name)') > > >>> > > )... > > > > >>> > > or > > > > >>> > > ,SQLField('person_name' > > >>> > > ,db.person.name.type > > >>> > > ,db.person.name.length > > >>> > > ,requires=IS_IN_DB(db,db.person.name) > > >>> > > )... > > > > >>> > > On Apr 13, 2:16 am, mdipierro <[email protected]> wrote: > > > > >>> > > > In trunk you can now do > > > > >>> > > > db.define_table('person : Name, Birthday date, Telephone') > > >>> > > > db.define_table('dog: Name, Owner person, Picture upload') > > > > >>> > > > Is this useful? Look at the source. Is the syntax reasonable? > > > > >>> > > > Massimo > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "web2py Web Framework" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/web2py?hl=en -~----------~----~----~----~------~----~------~--~---
