Well more I read more I think there is a real need but we are all wrong so instead of fighting please help us finding a solution.
@Mark: priorities or ordinal are great while you completely own the app and its config + it is a single technical version. I guess you know it is not always (rarely?) The case in medium and big projects. A sample can be: v1 you configure an url with host, port propertkes and in v2 it is directly the url cause you added a path. Can be the same for datasource and business config etc... What I did in practise was to use a filter mecanism but it was an ugly hack. For such cases you can maybe use PropertySource translators or things like that to ensure the config is in the right format and then merge with ordinal. Now let take the case where you package together several sub apps coming with their config. How do you do? Some config can conflict and the selection is not ordinal based - let me guess it will be the same. Best is to have both property sources and merge them into a single one. Kind of Properties merge(Properties current, PropertySource next). I am not happy with these solutions but the needs are here and not something thought but really met - even if I dont have your experiences. Point is we cant assume config will be perfect so let our future users make errors and be able to fix it easily. Le 27 déc. 2014 14:50, "Mark Struberg" <[email protected]> a écrit : > > No Anatole, I DO get it, but I really think it is a bad idea. Because it adds way too much complexity or a very limited benefit. > > > Think about it in an analogy to the ExpressionLanguage ELResolver chain. Of course this is a sorted lookup chain. And this list is fixed! > > And at runtime you cannot change the order and the user also does not care! > All he cares is that #{user.name} does the right thing. He does not have to express an 'evaluator' and the chain ordering for each and every EL invocation. It just does not make any sense from a users perspective. > > > > LieGrue, > strub > > > > > On Saturday, 27 December 2014, 14:17, Anatole Tresch <[email protected]> wrote: > > > > > > > >Hi Mark > > > > > >2014-12-27 12:56 GMT+01:00 Mark Struberg <[email protected]>: > > > >> The mechanism is clumsy and implies > >>> constraints that are already known as of now not matching all use cases. > >> > >>Tell me some limitations. Never had one. So just enlist them here and now. > >> > >And I am working since decades as well in the industry. I will not argue about use cases. I gave you same examples. You have the stand my opinion, unless you feel your opinion counts more than mine. > > > >> On top of it the priority leaks into the PropertySource API > >> > >> > >>Because it IS part of the PropertySource! > >> > > > >But it shoud not. I want to have my property sources and I want to combine them they way I want it. I want the concern of assembly being separated from the source itself. > >It is like you write a Java program like this: > > > > > >2: { > >4: } > > > >3: System.out.println(); > >1: for(int i=0;i<10;i11) > > > > > > > >Shows pretty much the nonsense of your argumentation. For priorizing the loading of components in CDI priorities are great and sufficient, here they are not. > > > > > >> Finally functions is the > >> > >>> modern way of modelling such an operation. > >> > >>If you have a hammer... > >>I'm not interested in style if it doesn't add any real benefit. > >> > >> > >If the hammer is more elegant and powerful but still easy than you outstyled solution, let it be a hammer! > > > >>> different or > >> > >>> partial overridings (common in complex environments) > >> > >>Never came across this need and I did very complex projects. It's always a trade off between an easy straight forward algorigthm which are easy to understand but sometimes you have to bend em a bit or program your own (PropertySource). The other option is to have hugely complex base mechanism which noone can use in practice because it is 'too flexible' - means not clear and straight enough. > >> > >> > >>> you will never get one solution, which a special type of > >> > >>> overridings that matches all users. > >>Oh sure we do. By having the ConfigSource define their ordinal themselves and it being really easy for a programmer to add own ConfigSources we have all of that! > >> > >> > >> > >>> A solution should NEVER constraint users in doing the stuff > >>> they want!* > >> > >>Having the sorting via Ordinal doesn't impose any restriction on the user. Because he can easily overwrite those values. > >>We are talking about a simple straight forward config mechanism and not about alien rocket science and time travelling. > >> > >> > >>>You are not on green field here! > >> > >> > >>Oh boy, we are! We just need to fulfil user needs, that's all. > >I am not a boy. I am an adult with 44 years on track.... ! > >And BTW you seem to have lost every kind of reality contact. Do you really think companies will change their internal systems completely because just a few guys think they know > >how the world is rouling...? NO! > > > >> > >>> *Of course not! (despite the fact that is trivial for the ones used the > >>> functional style of Java 8). > >>Of course I know Map#merge, but what do you use it for? To me it seems like an overkill. > >Seems that your mindis still stick on Java 7.,,, > > > >> You can still provide a singleton with > >>> constants, where you* > >>> *provide the most common combinations, see AggregationPolicy in my the > >>> current tree.* > >> > >>Again: I don't see the benefit. If I'm in an EAR and like to get my "documentarchive.endpoint.url" then WHY would I like to manually change the aggregation? Makes no sense to me. And this increases the complexity quite impressively. > >> > > > > > >Perhaps one day you realize that we are talking about a general configuration soultion. EE is a sepcial case, not the other way round. It is NOT like Deltaspike, which benefits the mechanism provided by CDI. It is not and if it will, it gets Deltaspike 2, which is useless. There is already one, which for its purposes on this level, I agree, works well. But for a general solution it lacks so much on functionality- > > > > > >I personally really think you still do not get the difference! It drives me crazy. > > > >LieGrue, > >>strub > >> > >> > >> > >> > >>> On Saturday, 27 December 2014, 12:28, Anatole Tresch < [email protected]> wrote: > >>> > *See inline...* > >>> > >>> 2014-12-27 11:42 GMT+01:00 Mark Struberg <[email protected]>: > >>> > >>>> Hi! > >>>> > >>>> 1.1) > >>>> > >>>> I think we agree that having a PropertySource/ConfigSource SPI with MANY > >>>> implementations is the way to go? > >>>> Any objections? > >>>> > >>> *+1 The way to go.* > >>> > >>> > >>> 1.2) > >>>> > >>>> Where should it belong to? Is it an API or rather an SPI? > >>>> I think it's more the later. A end user just likes to get the > >>> 'final' > >>>> configured values and does NOT deal with the PropertySources himself. It is > >>>> really just for extending the system -> SPI. > >>>> > >>> *+1 for PropertySource being an SPI. Configuration must be the API.* > >>> > >>> > >>> 1.3) > >>>> Merging. > >>>> Option (1.3.a) Do we like to do 'implicit' merging (aka the > >>> ordinal > >>>> stuff). > >>>> > >>> *It's not a question of taste. The mechanism is clumsy and implies > >>> constraints that are already known as of now not matching all use cases. On > >>> top of it the priority leaks into the PropertySoiurce API (as an additional > >>> method, which is a very ugly mix of concerns), Finally functions is the > >>> modern way of modelling such an operation.* > >>> > >>> > >>>> Option (1.3.b) Or do we like 'explicit' (the merge function). What > >>> benefit > >>>> does this add in practice? > >>>> > >>> > >>> *See above and as outlined multiple times. Adding additional functionality > >>> for audit (e.g. logging of the configuration overriding), different or > >>> partial overridings (common in complex environments). Please stop > >>> discussion on this priority thing, it's simply not enough! By the way the > >>> priority thing can still be implemented, when the rest of the design is > >>> done in a modular way. My proposed solution gave you the abtrsaction of a > >>> ConfigProvider BTW, where you could do this easily, but also the other > >>> stuff. What you do depends on the use case, and to some extent your > >>> personal taste. A solution should NEVER constraint users in doing the stuff > >>> they want!* > >>> > >>> Ad 1.3.a 'explicit' merging: This is basically the DeltaSpike mode: EACH > >>>> ConfigSource (PropertySource) has an ordinal which it can set itself. The > >>>> higher the configuration ordinal of the ConfigSource, the more important it > >>>> is and it will override values from ConfigSources with lower ordinal. > >>>> > >>>> That way it is possible to have a kind of 'default configuration' > >>> e.g. in > >>>> a property file inside your project and later overwrite it via -Dxxx=yyy, > >>>> JNDI, or some container provided MyCountainerAdminConfigSource etc later. > >>>> > >>> *No Mark. The fact of having a default configuration does not interconnect > >>> how this is evaluated and composed. You are wrong! And on top, when I look > >>> at your ideas: you will never get one solution, which a special type of > >>> overridings that matches all users. You have to provide building blocks > >>> (one more) that helps the users (companies) to model their functionality > >>> with it. You are not on green field here!* > >>> > >>> Ad 1.3.b 'implicit' merging: Well, actually I don't got this. There > >>> was > >>>> merge(String key, PropertySource s1, s2), but that would mean that every > >>>> user needs to deal with that himself? Could you please elaborate on that > >>>> option? I didn't get it.. > >>> > >>> *Of course not! (despite the fact that is trivial for the ones used the > >>> functional style of Java 8). You can still provide a singleton with > >>> constants, where you* > >>> *provide the most common combinations, see AggregationPolicy in my the > >>> current tree.* > >>> > >>> *-Anatole* > >>> > >>> > >>>> > >>>> > >>> > >>>> LieGrue, > >>>> strub > >>>> > >>> > >>> > >>> > >>> -- > >>> *Anatole Tresch* > >>> Java Engineer & Architect, JSR Spec Lead > >>> Glärnischweg 10 > >>> CH - 8620 Wetzikon > >>> > >>> *Switzerland, Europe Zurich, GMT+1* > >>> *Twitter: @atsticks* > >>> *Blogs: **http://javaremarkables.blogspot.ch/ > >>> <http://javaremarkables.blogspot.ch/>* > >>> > >>> *Google: atsticksMobile +41-76 344 62 79* > >> > >>> > >> > > > > > > > > > >-- > > > >Anatole Tresch > >Java Engineer & Architect, JSR Spec Lead > >Glärnischweg 10 > >CH - 8620 Wetzikon > > > > > >Switzerland, Europe Zurich, GMT+1 > >Twitter: @atsticks > >Blogs: http://javaremarkables.blogspot.ch/ > >Google: atsticks > >Mobile +41-76 344 62 79 > > > >
