All very interesting! Over the years I tried numerous modelling tools and only the low-tech ones stayed: drawing on a whiteboard, using coloured index cards [1] (learned from Dan) or using a simple online tool like yUML [2]. And I only use them to communicate the broad picture or for explorative purposes.
I gave up on code generators: I always ended up fighting the generated code. And the impression that they support rapid application development proved wrong: at the point where you had to work on more advanced stuff velocity came to a halt. If an application is built on lots of repeating code snippets then my conclusion is that the underlying framework is not good enough. I love source code that tells the story of the application. Where everything that could be left out of the code is eliminated. Very DRY, convention over code. This has drawn me to Naked Objects and made me decide to spend my time on Apache Isis. As you imagine by now I would not take the route from diagram to code. For me the code editor is the sole canvas to express your ideas. And I think that if we keep improving Apache Isis on a few points there will never be a need for an additional tool: 1) Reduce boilerplate and make writing an application skeleton as easy as the easiest modelling tool. This has the advantage that a software architect can sketch the application and leave it to his developers to fill in details. But everyone is working on the same code base using the same tools. In this area we started using Lombok. Also Dan had an idea to make it possible to create your own custom annotations which can combine multiple annotations. 2) Visualise the meta model. With contributions and mixins the application logic can come from anywhere. This is architecturally sane but makes an application hard to grasp. It would love to see a maven plugin that generates appealing documentation from the meta model of an Isis application. 3) When taking the visualisation concept a bit further it would be very powerful to explore and navigate the meta model within the IDE. Any plugin developers here? That's just my two cents. Cheers, Jeroen On 15 November 2015 at 21:01, David Tildesley <davo...@yahoo.co.nz> wrote: > > > > > > On Sunday, 15 November 2015 5:37 AM, Dan Haywood < > d...@haywood-associates.co.uk> wrote: > > Thanks for this James. > > > My observation re: using the (relational) data model as the initial input > > though is that this is likely to lead to rather coupled code, ultimately > > not maintainable. > > Couldn't agree more. > > > > So, while going from the database up to the domain is fine for a single > > module of 10 or so entities, any app that is bigger than this really > should > > be modelled from the domain down to the database. > > Quite right. Any business app that is non trivial should be domain > modelled. > > David. > > > Dan > > > > > > On 14 November 2015 at 15:00, James Agada <james.ag...@cwg-plc.com> wrote: > > > I actually tested out using Telosys to generate an isis app from database > > definition. It did work but of course it meant i did the ER first. I used > > MySQL, did the ER modelling on the workbench, forward engineered into the > > database and then used telosys scripts to generate a functional Isis > > application. Did it as a PoC but we will come back to it later. > > James Agada > > Chief Technology Officer > > > > > > On 14 Nov 2015, at 3:49 PM, Óscar Bou - GOVERTIS <o....@govertis.com> > > wrote: > > > > Many thanks, Stephen for this detailed explanation. > > > > The problem I’m facing is that I intent to communicate the developers > > what’s the model to implement. > > > > And I usually don’t find big mistakes in action code, but what mostly > > forces us to refactor is miscommunication regarding the Domain Entities, > > attributes and actions names, including typos (think my team speak > Spanish > > but they’re modeling in English) or wrong or missing relationships > between > > those entities. > > > > All that could be avoided by firstly agree in a common UML Class Diagram. > > > > If it can potentially generate automatically the Java skeleton with > Apache > > Isis annotations is a big plus, as it will avoid mistakes when moving > from > > design to implementation. > > > > And if it could potentially reverse engineer Java (incl. Apache Isis > > idioms) a really good feature. > > > > Any ideas about what tools could best adapt to the workflow (that could > be > > potentially customized to cover the last 2 whishes) ? > > > > > > Thanks, > > > > Oscar > > > > > > > > > > El 14 nov 2015, a las 2:03, Stephen Cameron <steve.cameron...@gmail.com> > > escribió: > > > > Hi Oscar, > > > > In a qualified way I think your idea has merit. I have never used UML for > > design, but a few years ago I decided to take a good look at it and see > it > > if was useful. The idea of being able to draw a diagram and generate code > > from it seemed sensible, after all that is what is done by most other > > 'design' professions, such as building architects and engineers. > > > > To cut a long story short I realised after some reading that it was not > > that simple, and that OO languages themselves are really all that are > > needed for the process of designing a system. This is "the code is the > > design" school of thought, mainly attributed to Jack Reeves [1]. > > > > I found that keeping code and UML diagrams in sync in a top-down 'UML to > > code' design process will always be problematic (maybe why there are > > apparently no open-source tools that claim to do this). Then I read about > > Domain Driven Design which seemed to agree with this premise, and from > > there found Apache Isis via Dan's book. > > > > So now for me UML class diagrams do have an after the fact use for > > documentation purposes and if a solution implement was capable of that > > reverse generation of diagrams from code it would be a good thing to > have. > > Entity Framework can do this, its their "code first" approach. > > > > Given that the-code-is-the-design is true, I think that UML class > diagrams > > real main value is as a data model, the question then is why not use a > > purely data-modeling tool and generate Java classes off it. Then the > > diagrams 'designed' could have a usefulness to programmers and to system > > users, something like those created SchemaSpy [2] for example. > > > > There are already useful and free Java class generation (binding) tools > > from off data-models, of one sort or another, such as JAXB, DataNucleus' > > schemaGen[3], even CAM [4]. > > > > Here is my vision of what I think would be really useful: to have a > design > > tool that can be used by non-programmers to create a simple data-model, > and > > then to have that create a working Apache Isis based CRUD system. This > > could serve your purpose (I guess) and also find a wider use. > > > > The means of achieving this would I think, require something like the > > "dynamic classes" in available in the Moxy framework [5], that is, map > > based so that no Java class compilation is needed. Instead, a data-model > > configuration file (a schema) is read-in to configure the system. This is > > not a strange idea, in fact its the data-driven programming paradigm that > > is the basis of the original browser concept (before it was turned into > OO > > application framework via addition of Javascript). In the browser the > data > > is HTML that is turned into an in-memory Document Object Model (DOM) for > > rendering. > > > > As a blended solution between Apache Isis as it is currently (heavily > > influence by naked objects, an OO modelling based approach for creating > > custom *behavioural* applications) and this additional mainly data > focused > > approach, I think a programmer developing a business application would > > start off with these dymanic classes and then in time 'harden' the design > > by generating and compiling real Java classes from off the model. [A > > non-programmer wouldn't get past the first design 'phase' usually, but > > still end up with a useable UI.] > > > > In addition, by having separate abstract model-generated classes, that > can > > be overwritten if the data-model changes, and concrete implementation > > classes, where you put all your behavioural code and that are never > > overwritten, you get close to the 'round-tripping' that would seem to me > to > > be the only valid way to use UML *for design*. I think this is how the > > Eclipse Ecore models work, that there are model classes and > implementation > > classes that extend the model classes. The IDE will often warn you when > > these two sub-models have inconsistencies. This duality also offers an > > alternative means to achieving the goals of Lombok it would seem. > > > > Of course, sitting in the middle of all this is a meta-model, that > creates > > the dynamic classes, generates and compiles the 'hardened' model classes > > (when used) and maps either of these means to a UI 'viewer'. > > > > For such data-management frameworks, the complicated aspect isn't so much > > going from the designed data-model to Java, there are lots of examples of > > that, instead its being able to have also, a dynamic query capability. So > > that a person unfamiliar with the dataset, can, via its data-model, start > > querying it (and also maybe integrating it in real-time with other online > > resources, the idea of a data-browser appeals!). > > > > In the science domain, where I worked for a few years building > > data-management infrastructure, there are highly advanced systems for > > online data access and querying e.g. [6], but at the same time a common > > tool used for small databases is still Microsoft Access. Access has many > > strengths as a desktop database, including form generation and also > dynamic > > query-by-form, but the problems arise when you want to make such data > > publicly available, in the sense of being findable and searchable in real > > time. You might as well have used a web-based system from the start and > > then been able to easily open it to the world at the appropriate time. > > > > Having though about this problem for a number of years and spent alot of > > time working on a XForms based solution as well. I'd be very interested > to > > see Apache Isis broaden its scope to offer what I have described, in fact > > its doesn't seem to need very much more than what is already present in > the > > Isis meta-model and Wicket viewer. The Restful objects support already > > provides a generic 'generated' web programming interface. > > > > In summary I know that there are some Java projects that make very > > effective use of a Model Driven Architecture approach (e.g [7]), but I am > > now not sure that UML is the 'be-all-and-end-all' basis of that. > Actually I > > think that data-models are the basis of most of MDAs efficiency dividends > > and that there are other approaches, specifically that conceptual models > > offer more versatility in terms of who and how you can make use of them. > > This thinking goes way back, such as Sowa's Conceptual Graphs [8] and > even > > to Codd [9]. A modern expression of Sowa's thoughts (I gather) is the W3C > > semantic web, but he was thinking of database design and query way back. > > > > Apart from some additions to Isis, another interesting aspect is looking > at > > the mapping to data-stores, using a graph database of one sort or another > > to avoid the complexity of ORM is a simple answer to that I feel. Again, > > the hardening of a design might mean manually adding a few overrides of > > default ORM mapping rules into some behavioural-model classes, that > extend > > generated data-model classes (getters and setters only). > > > > > > [1]http://www.developerdotstar.com/mag/articles/reeves_design_main.html > > [2]http://schemaspy.sourceforge.net/sample/relationships.html > > [3] > > > > > http://www.datanucleus.org/products/accessplatform_2_1/rdbms/schematool.html > > [4]http://camprocessor.sourceforge.net/wiki/index.php/Main_Page > > [5]https://wiki.eclipse.org/EclipseLink/Examples/MOXy/Dynamic > > [6]http://www.opendap.org/ > > [7]http://www.opencrx.org/ > > [8]https://en.wikipedia.org/wiki/Conceptual_graph > > [9]https://en.wikipedia.org/wiki/Relational_Model/Tasmania > > > > > > > > On Fri, Nov 13, 2015 at 8:45 PM, Óscar Bou - GOVERTIS < > o....@govertis.com> > > wrote: > > > > > > Hi all. > > > > I’m considering re-introducing UML Class diagrams in our workflow mainly > > for: > > - graphically design the domain entities. > > - modeling relationships. > > - agree with names of properties, collections and actions needed. > > > > It would be wonderful if the UML solution could also be “integrated” with > > Apache Isis or Java, automating at least the entities Java skeleton > > generation. > > > > I’ve worked extensively with Rational Rose and Sparx EnterpriseArchitect, > > but was thinking about an Eclipse-based solution that could “potentially” > > be adapted to generate the Java entities with Isis annotations. > > > > Before joining the Apache Isis community I developed [1] for Enterprise > > Architect for automatically generating Spring Roo-based classes, but Isis > > was better suited for our project and I abandoned it. > > > > > > Any ideas? > > > > Thanks, > > > > Oscar > > > > > > [1] http://roomodeler.com > > > > > > > > > > > > > > This email and any attachment thereto are confidential and priviledged. > if > > you have received it in error, please delete immediately and notify the > > sender. 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