Re: DDD Implementation: Marker interfaces for all classes
"Niklas Mehner [email protected] [domaindrivendesign]" <[email protected]> Sat, 13 Aug 2016 20:53:35 +0200
| Newsgroups | gmane.comp.programming.domain-driven-design |
|---|---|
| Message-ID | <CANx61CUL9A60KsAnGG3pmAdFeaGJ=ftSyunt_M3SMwHzxVg-Qw@mail.gmail.com> |
--94eb2c05ad303585a00539f884a0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="UTF-8" Thank you for all your answers, but I seem to not have put this the right w= ay. This is not about a naming convention for classes, but about marking c= lasses with an interface (that is not a base class but only an empty interf= ace like Serializable in java). Similar to what Caleb described using the s= pring annotations only using interfaces. With the additional requirement t= hat each class HAS TO be assigned to a building block. And that is the part= I find problematic and wonder if anybody has done this (successfully) in a= ny project. To put this in perspective: People in this project are coming = from a 4GL background using a tool with very limited set of concepts/capabi= lities. The new development platform is JEE. Now they are concerned that th= ere will be chaotic code structures and want to limit this by only allowing= a defined set of building blocks and no classes that do not conform to the= se building blocks. I don't see how this could possibly work, but wanted t= o know if anybody has done anything like this before. I hope this explains= the issue a bit better. 2016-08-13 18:36 GMT+02:00 Paul Rayner paul@virtu= al-genius.com [domaindrivendesign] <[email protected]>: >= > > > > On Sat, Aug 13, 2016 at 12:28 AM, Niklas Mehner niklas.mehner@gmai= l.com > [domaindrivendesign] <[email protected]> wrote: > = >> >> >> Hello everyone, >> >> We are currently in a somewhat heated discus= sions about the design for a >> new software. >> >> One of the discussion p= oints is the use of marker interfaces. >> >> I am perfectly fine with using= marker interfaces like: >> >> SomeService implements DomainService { >> = ... >> } >> >> to make the architecture visible in the code and implement = some >> verification of code properties. >> >> But now some people want to = add the requirement to have assign each class >> to a building block (Entit= y/Value Object/Service/...). >> Has anybody ever successfully done this? Is= this even possible without >> some "GenericImplementationObject" building = block? >> > > Are you saying you want to have each class named according to= its building > block pattern name, or something like that? I can't think o= f any good > reason to do this. The building block patterns are *not* the i= mportant > concepts in your domain model, the ubiquitous language is. Focus= *first* > on the language of your domain model. The implementation pattern= s used to > represent the concepts are secondary concerns. > > > --94eb2c05ad303585a00539f884a0 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable <head> <style type=3D"text/css"> <!-- /* start of attachment style */ .ygrp-photo-title{ clear: both; font-size: smaller; height: 15px; overflow: hidden; text-align: center; width: 75px; } div.ygrp-photo{ background-position: center; background-repeat: no-repeat; background-color: white; border: 1px solid black; height: 62px; width: 62px; } div.photo-title=20 a, div.photo-title a:active, div.photo-title a:hover, div.photo-title a:visited { text-decoration: none;=20 } div.attach-table div.attach-row { clear: both; } div.attach-table div.attach-row div { float: left; /* margin: 2px;*/ } p { clear: both; padding: 15px 0 3px 0; overflow: hidden; } div.ygrp-file { width: 30px; valign: middle; } div.attach-table div.attach-row div div a { text-decoration: none; } div.attach-table div.attach-row div div span { font-weight: normal; } div.ygrp-file-title { font-weight: bold; } /* end of attachment style */ --> </style> </head> <html> <head> <style type=3D"text/css"> <!-- #ygrp-mkp { border: 1px solid #d8d8d8; font-family: Arial; margin: 10px 0; padding: 0 10px; } #ygrp-mkp hr { border: 1px solid #d8d8d8; } #ygrp-mkp #hd { color: #628c2a; font-size: 85%; font-weight: 700; line-height: 122%; margin: 10px 0; } #ygrp-mkp #ads { margin-bottom: 10px; } #ygrp-mkp .ad { padding: 0 0; } #ygrp-mkp .ad p { margin: 0; } #ygrp-mkp .ad a { color: #0000ff; text-decoration: none; } --> </style> </head> <body> <!-- |**|begin egp html banner|**| --> <br><br> <!-- |**|end egp html banner|**| --> <div dir=3D"ltr"><div><div><div><div><div>Thank you for all your answers, b= ut I seem to not have put this the right way.<br><br></div>This is not abou= t a naming convention for classes, but about marking classes with an interf= ace (that is not a base class but only an empty interface like Serializable= in java).<br></div>Similar to what Caleb described using the spring annota= tions only using interfaces.<br><br></div>With the additional requirement t= hat each class HAS TO be assigned to a building block. And that is the part= I find problematic and wonder if anybody has done this (successfully) in a= ny project.<br><br></div>To put this in perspective: People in this project= are coming from a 4GL background using a tool with very limited set of con= cepts/capabilities. The new development platform is JEE. Now they are conce= rned that there will be chaotic code structures and want to limit this by o= nly allowing a defined set of building blocks and no classes that do not co= nform to these building blocks. <br><br></div><div>I don't see how this= could possibly work, but wanted to know if anybody has done anything like = this before.<br><br></div><div>I hope this explains the issue a bit better.= <br></div><div><div><div><div><br><div><div><div class=3D"gmail_extra"><div= class=3D"gmail_quote">2016-08-13 18:36 GMT+02:00 Paul Rayner <a href=3D"ma= ilto:[email protected]">[email protected]</a> [domaindrivendesi= gn] <span dir=3D"ltr"><<a href=3D"mailto:domaindrivendesign@yahoogroups.= com" target=3D"_blank">[email protected]</a>></span>:<b= r><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;borde= r-left:1px solid rgb(204,204,204);padding-left:1ex"> <u></u> =20 <div style=3D"background-color:rgb(255,255,255)"> <span>=C2=A0</span> <div> <div> <div> =20=20=20=20=20=20 =20=20=20=20=20=20 <p></p><div dir=3D"ltr"><br><div class=3D"gmail_extra"><br><div class= =3D"gmail_quote"><span class=3D"">On Sat, Aug 13, 2016 at 12:28 AM, Niklas = Mehner <a href=3D"mailto:[email protected]" target=3D"_blank">niklas.= [email protected]</a> [domaindrivendesign] <span dir=3D"ltr"><<a href=3D"= mailto:[email protected]" target=3D"_blank">domaindrivende= sign@<wbr>yahoogroups.com</a>></span> wrote:<br><blockquote class=3D"gma= il_quote" style=3D"border-left:1px solid rgb(204,204,204)"> <u></u> =20 <div style=3D"background-color:rgb(255,255,255)"> <span>=C2=A0</span> <div> <div> <div> =20=20=20=20=20=20 =20=20=20=20=20=20 <p></p><div dir=3D"ltr"><div><div><div><div><div><div><div><div>Hello= everyone,<br><br></div>We are currently in a somewhat heated discussions a= bout the design for a new software.<br><br></div>One of the discussion poin= ts is the use of marker interfaces.<br><br></div>I am perfectly fine with u= sing marker interfaces like:<br><br></div>SomeService implements DomainServ= ice {<br>=C2=A0=C2=A0 ...<br>}<br><br></div><div>to make the architecture v= isible in the code and implement some verification of code properties.<br><= /div><div><br></div>But now some people want to add the requirement to have= assign each class to a building block (Entity/Value Object/Service/...).<b= r></div>Has anybody ever successfully done this? Is this even possible with= out some "GenericImplementationObject" building block?<br></div><= /div></div></div></div></div></div></blockquote><div><br></div></span><div>= Are you saying you want to have each class named according to its building = block pattern name, or something like that? I can't think of any good r= eason to do this. The building block patterns are <i>not</i> the important = concepts in your domain model, the ubiquitous language is. Focus <i>first</= i> on the language of your domain model. The implementation patterns used t= o represent the concepts are secondary concerns.</div></div></div></div> <p></p> </div> =20=20=20=20=20 =20=20=20=20 <div style=3D"color:rgb(255,255,255);min-height:0px"></div> </div> =20=20 </blockquote></div><br></div></div></div></div></div></div></div></div> <!-- |**|begin egp html banner|**| --> <br> <br> <!-- |**|end egp html banner|**| --> <div width=3D"1" style=3D"color: white; clear: both;"/>__._,_.___</div> =20=20=20=20=20=20 =20=20 =20=20=20=20 <div id=3D"fromDMARC" style=3D"clear:both; margin-top: 10px;"> <hr style=3D"height:2px ; border-width:0; color:#E3E3E3; backgroun= d-color:#E3E3E3;"> Posted by: Niklas Mehner <[email protected]> <= hr style=3D"height:2px ; border-width:0; color:#E3E3E3; background-color:#E= 3E3E3;"> </div> <!-- Start Recommendations --> <!-- End Recommendations --> <!-- |**|begin egp html banner|**| --> <img src=3D"http://geo.yahoo.com/serv?s=3D97476590/grpId=3D8116923/grpspI= d=3D1705007181/msgId=3D24788/stime=3D1471123418" width=3D"1" height=3D"1"> = <br> <!-- |**|end egp html banner|**| --> =20=20 <!-- |**|begin egp html banner|**| --> <br> =20=20=20 =20=20=20=20=20 =20 <!-- |**|begin egp html banner|**| --> <div id=3D"ygrp-vital" style=3D"background-color: #f2f2f2; font-fam= ily: Verdana; font-size: 10px; margin-bottom: 10px; padding: 10px;"> <span id=3D"vithd" style=3D"font-weight: bold; color: #333; text-tr= ansform: uppercase; "><a href=3D"https://groups.yahoo.com/neo/groups/domain= drivendesign/info;_ylc=3DX3oDMTJlc3NyZzBkBF9TAzk3MzU5NzE0BGdycElkAzgxMTY5Mj= MEZ3Jwc3BJZAMxNzA1MDA3MTgxBHNlYwN2dGwEc2xrA3ZnaHAEc3RpbWUDMTQ3MTEyMzQxNw--"= style=3D"text-decoration: none;">Visit Your Group</a></span> <ul style=3D"list-style-type: none; margin: 0; padding: 0; display: in= line;"> <li style=3D"border-right: 1px solid #000; font-weight: 700; di= splay: inline; padding: 0 5px; margin-left: 0;"> <span class=3D"cat"><a href=3D"https://groups.yahoo.com/neo/groups/do= maindrivendesign/members/all;_ylc=3DX3oDMTJmN3ByNTQ0BF9TAzk3MzU5NzE0BGdycEl= kAzgxMTY5MjMEZ3Jwc3BJZAMxNzA1MDA3MTgxBHNlYwN2dGwEc2xrA3ZtYnJzBHN0aW1lAzE0Nz= ExMjM0MTc-" style=3D"text-decoration: none;">New Members</a></span> <span class=3D"ct" style=3D"color: #ff7900;">2</span> </li> </ul> </div> <div id=3D"ft" style=3D"font-family: Arial; font-size: 11px; margin-top: 5p= x; padding: 0 2px 0 0; clear: both;"> <a href=3D"https://groups.yahoo.com/neo;_ylc=3DX3oDMTJkbTZrcXI1BF9TAzk3ND= c2NTkwBGdycElkAzgxMTY5MjMEZ3Jwc3BJZAMxNzA1MDA3MTgxBHNlYwNmdHIEc2xrA2dmcARzd= GltZQMxNDcxMTIzNDE4" style=3D"float: left;"><img src=3D"http://l.yimg.com/r= u/static/images/yg/img/email/new_logo/logo-groups-137x15.png" height=3D"15"= width=3D"137" alt=3D"Yahoo! 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