Re: DDD Implementation: Marker interfaces for all classes
"Niklas Mehner [email protected] [domaindrivendesign]" <[email protected]> Sun, 14 Aug 2016 21:49:26 +0200
| Newsgroups | gmane.comp.programming.domain-driven-design |
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| Message-ID | <CANx61CUvY3-enfcXHRRvSfq09cpv6z-VLicjpu3a_+QHkQSOYQ@mail.gmail.com> |
--f403045cb0e4cdc586053a0d690d Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="UTF-8" There is of course nothing wrong with using annotations. But the core of th= e issue for me is to have to assign every class to a building block at all.= If you do this by adding a marker interface or an annotation is then only = the technical means of achieving this. 2016-08-13 23:52 GMT+02:00 Caleb Cu= shing [email protected] [domaindrivendesign] <domaindrivendesign@yaho= ogroups.com>: > > > ok, so it's JEE what's wrong with using annotations li= ke Spring Does? even > if you're not using Spring CDI allows you to make yo= ur own annotations. > Arguably marker interfaces are a mistake in java and = lead to no end of > issues. > > On Sat, Aug 13, 2016 at 4:29 PM Niklas Mehn= er [email protected] > [domaindrivendesign] <domaindrivendesign@yahoo= groups.com> wrote: > >> >> >> Thank you for all your answers, but I seem to= not have put this the right >> way. >> >> This is not about a naming conve= ntion for classes, but about marking >> classes with an interface (that is = not a base class but only an empty >> interface like Serializable in java).= >> Similar to what Caleb described using the spring annotations only using= >> interfaces. >> >> With the additional requirement that each class HAS T= O be assigned to a >> building block. And that is the part I find problemat= ic and wonder if >> anybody has done this (successfully) in any project. >>= >> To put this in perspective: People in this project are coming from a 4G= L >> background using a tool with very limited set of concepts/capabilities= . The >> new development platform is JEE. Now they are concerned that there= 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 = these building >> blocks. >> >> I don't see how this could possibly work, b= ut wanted to know if anybody >> has done anything like this before. >> >> I= hope this explains the issue a bit better. >> >> 2016-08-13 18:36 GMT+02:0= 0 Paul Rayner [email protected] >> [domaindrivendesign] <domaindriven= [email protected]>: >> >>> >>> >>> >>> >>> On Sat, Aug 13, 2016 at 12:= 28 AM, Niklas Mehner [email protected] >>> [domaindrivendesign] <doma= [email protected]> wrote: >>> >>>> >>>> >>>> Hello everyone, >= >>> >>>> We are currently in a somewhat heated discussions about the design= for >>>> a new software. >>>> >>>> One of the discussion points is the use= of marker interfaces. >>>> >>>> I am perfectly fine with using marker inte= rfaces like: >>>> >>>> SomeService implements DomainService { >>>> ... >= >>> } >>>> >>>> to make the architecture visible in the code and implement = some >>>> verification of code properties. >>>> >>>> But now some people wa= nt to add the requirement to have assign each >>>> class to a building bloc= k (Entity/Value Object/Service/...). >>>> Has anybody ever successfully don= e this? Is this even possible without >>>> some "GenericImplementationObjec= t" building block? >>>> >>> >>> Are you saying you want to have each class = named according to its >>> building block pattern name, or something like t= hat? I can't think of any >>> good reason to do this. The building block pa= tterns are *not* the >>> important concepts in your domain model, the ubiqu= itous language is. Focus >>> *first* on the language of your domain model. = The implementation >>> patterns used to represent the concepts are secondar= y concerns. >>> >>> >> >> >> -- > Caleb Cushing > > http://xenoterracide.co= m > > > --f403045cb0e4cdc586053a0d690d 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">There is of course nothing wrong with using annotations. B= ut the core of the issue for me is to have to assign every class to a build= ing block at all. If you do this by adding a marker interface or an annotat= ion is then only the technical means of achieving this.<br><div class=3D"gm= ail_extra"><br><div class=3D"gmail_quote">2016-08-13 23:52 GMT+02:00 Caleb = Cushing <a href=3D"mailto:[email protected]" target=3D"_blank">xenote= [email protected]</a> [domaindrivendesign] <span dir=3D"ltr"><<a href=3D= "mailto:[email protected]" target=3D"_blank">domaindrivend= esign@<wbr>yahoogroups.com</a>></span>:<br><blockquote class=3D"gmail_qu= ote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex= "> <u></u> =20 <div style=3D"background-color:#fff"> <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">ok, so it's JEE what's wrong with usi= ng annotations like Spring Does? even if you're not using Spring CDI al= lows you to make your own annotations. Arguably marker interfaces are a mis= take in java and lead to no end of issues.</div><span><br><div class=3D"gma= il_quote"><div dir=3D"ltr">On Sat, Aug 13, 2016 at 4:29 PM Niklas Mehner <a= href=3D"mailto:[email protected]" target=3D"_blank">niklas.mehner@gm= ail.com</a> [domaindrivendesign] <<a href=3D"mailto:domaindrivendesign@y= ahoogroups.com" target=3D"_blank">domaindrivendesign@yahoogroup<wbr>s.com</= a>> wrote:<br></div><blockquote class=3D"gmail_quote" style=3D"border-le= ft:1px #ccc solid"> =20=20=20=20=20=20=20=20 <div> <br><br> <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 dir=3D"ltr"><div><div><div><div><br><div><d= iv><div class=3D"gmail_extra"><div class=3D"gmail_quote">2016-08-13 18:36 G= MT+02:00 Paul Rayner <a href=3D"mailto:[email protected]" target=3D"_= blank">[email protected]</a> [domaindrivendesign] <span dir=3D"ltr">&= lt;<a href=3D"mailto:[email protected]" target=3D"_blank">= domaindrivendesign@yahoogroup<wbr>s.com</a>></span>:<br><blockquote clas= s=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid r= gb(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"><br><div class=3D"gmail_extra"><br><div class= =3D"gmail_quote"><span>On Sat, Aug 13, 2016 at 12:28 AM, Niklas Mehner <a h= ref=3D"mailto:[email protected]" target=3D"_blank">niklas.mehner@gmai= l.com</a> [domaindrivendesign] <span dir=3D"ltr"><<a href=3D"mailto:doma= [email protected]" target=3D"_blank">domaindrivendesign@yahoog= roup<wbr>s.com</a>></span> wrote:<br><blockquote class=3D"gmail_quote" s= tyle=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 </div></div></blockquote></div><br></div></div></div></div></div></div></di= v></div></div><div><div dir=3D"ltr"></div> <br> <br> <div width=3D"1" style=3D"color:white"></div> </div></blockquote></div></span><span><div dir=3D"ltr">-- <br></div><div da= ta=3D"https://ci4.googleusercontent.com/proxy/CpYzkcDKjPf-NqFCSu4GBqoQ_5P1d= DkfTMWPGDqglo-e-uanL4gIS02e2U0=3Ds0-d-e1-ft#http://gmail_signature"><div di= r=3D"ltr">Caleb Cushing<div><br></div><div><a href=3D"http://xenoterracide.= com" target=3D"_blank">http://xenoterracide.com</a></div></div></div> </span><p></p> </div> =20=20=20=20=20 =20=20=20=20 <div style=3D"color:#fff;min-height:0"></div> </div> =20=20 </blockquote></div><br></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=3D24792/stime=3D1471232961" 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=3DX3oDMTJlMXY0cG1wBF9TAzk3MzU5NzE0BGdycElkAzgxMTY5Mj= MEZ3Jwc3BJZAMxNzA1MDA3MTgxBHNlYwN2dGwEc2xrA3ZnaHAEc3RpbWUDMTQ3MTIzMjk2MQ--"= 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=3DX3oDMTJmbG0wcXFhBF9TAzk3MzU5NzE0BGdycEl= kAzgxMTY5MjMEZ3Jwc3BJZAMxNzA1MDA3MTgxBHNlYwN2dGwEc2xrA3ZtYnJzBHN0aW1lAzE0Nz= EyMzI5NjE-" 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=3DX3oDMTJkNW85NjFvBF9TAzk3ND= c2NTkwBGdycElkAzgxMTY5MjMEZ3Jwc3BJZAMxNzA1MDA3MTgxBHNlYwNmdHIEc2xrA2dmcARzd= GltZQMxNDcxMjMyOTYx" 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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