ParameterCatalogs.html

<ul>
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<p>Concepts: features, resources, perspectives, views, editors</p>
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<p>Opening perspectives and views</p>
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<p>Installing new software manually</p>
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<p>Team support with Git</p>
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<p>Learn how to use the Ecore diagram editor</p>
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<p>Launch the Eclipse Marketplace</p>
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<div class="paragraph">
<p>For now, you can dismiss the welcome screen. It can be opened anytime by executing <code>Help &#8594; Welcome</code></p>
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<div class="sect2">
<h3 id="truemodeling-parameter-catalogs-for-simulation-with-ecore"><a class="anchor" href="#truemodeling-parameter-catalogs-for-simulation-with-ecore"></a>Modeling Parameter Catalogs for Simulation with Ecore</h3>
<div class="paragraph">
<p>Now you should see the initial layout of Eclipse with <em>Model Explorer</em> and <em>Outline</em> on the left and a big empty editing area with <em>Properties</em> view below to the right.</p>
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<p>Since we will use Ecore diagrams for data modeling, create your first Ecore modeling project now:</p>
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<p>Execute <code>File &#8594; New &#8594; Ecore Modeling Project</code> from main menu&#8201;&#8212;&#8201;not <code>Modeling Project</code>!</p>
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<p>Name it <code>demo.catalog</code> and click <code>Next &gt;</code></p>
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<p>Uncheck <code>Use Default Location</code> so that the new project is <strong>not</strong> stored in workspace, but a different directory you create/choose, then click <code>Next &gt;</code></p>
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<p>Provide <code>democatalog</code> as main Java package name and click <code>Finish</code>.</p>
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<p>Eclipse should look like below with an new empty graphical Ecore diagram editor opened.
The diagram is automatically named <code>democatalog</code> after the package name for the Java classes that will be generated from it (provided above).
The <em>Model Explorer</em> shows the contents of the new Ecore modeling project.</p>
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<img src="ParameterCatalogs2Images/DemoCatalogEmpty.png" alt="DemoCatalogEmpty">
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<div class="title">Figure 3. New Ecore Modeling Project</div>
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<p>To get your feet wet, do this:</p>
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<p>Drag a <em>Class</em> from the palette on the right onto the editor&#8217;s canvas: it will materialize as a rectangle labeled <code>NewEClass1</code>.</p>
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<p>The class symbol should be selected initially, so you can see its attributes in the <em>Properties</em> view.</p>
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<p>In there replace <code>NewEClass1</code> by <code>EnergyComponentsCatalog</code> to rename the class.</p>
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<p>Click anywhere on the canvas and notice that the class symbol is deselected and the toolbar at the top adapts accordingly.</p>
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<p>In the toolbar change <code>100%</code> to <code>75%</code> to scale diagram.</p>
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<p>Execute <code>File &#8594; Save</code> to save model and diagram on disk.</p>
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<p>Close diagram editor <code>democatalog</code> by closing its tab.</p>
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<p>Reopen saved diagram by double click on entry <code>democatalog</code> in <em>Model Explorer</em>.</p>
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<p>Technically, everything is in place now to begin modeling the data that the projected catalog shall contain.
Except &#8230;&#8203; understanding the basics of object-oriented modeling would be helpful.
This is why developers should support domain experts at this stage.</p>
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<div class="title">Model Data with Class Diagrams</div>
<p>Ecore diagrams are simplified UML class diagrams.
Here some resources on what this is all about:</p>
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<ul>
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<p><a href="http://www.cs.toronto.edu/~sme/CSC340F/slides/11-objects.pdf">Toronto Lecture on Object Oriented Modeling</a></p>
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<p><a href="http://agilemodeling.com/artifacts/classDiagram.htm">UML 2 Class Diagrams: An Agile Introduction</a></p>
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<p><a href="https://www.amazon.de/UML-Classroom-Einführung-objektorientierte-Modellierung-ebook/dp/B00AIBE1QA/ref=sr_1_2?__mk_de_DE=ÅMÅŽÕÑ&amp;dchild=1&amp;keywords=UML&amp;qid=1585854599&amp;sr=8-2">UML @ Classroom: Eine Einführung in die objektorientierte Modellierung (German Book)</a></p>
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</ul>
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<p>Beginners are strongly encouraged to read the first two resources.
The first one contains a gentle introduction, especially suited for domain experts.
The second one can also serve as reference.</p>
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<p>We will touch central object-oriented concepts <em>Class</em>, <em>Object</em>, <em>Attribute</em>, <em>Association</em>, <em>Composition</em>, and <em>Multiplicity</em> in an example below, but work through above sources to get a deeper understanding and to enhance your modeling skills.</p>
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<div class="paragraph">
<p>Note that above sources differentiate between <em>conceptual</em> and <em>detailed</em> models.
All in all we go for detailed models, since only these contain enough information to generate code.
Having said this, it is usually a good idea to have two or three conceptual iterations at a white board to agree on the broad approach before going too much into detail.
But even if one starts with Ecore models right away, these also can be adapted any time to follow a new train of thought.</p>
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<div class="paragraph">
<p>See here the essential and typical structure of a parameter catalog in a class diagram.
Instead of artificial example classes like <em>Foo</em> and <em>Bar</em> it shows classes from an existing catalog, albeit in very condensed form.</p>
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<img src="http://localhost:56397/afx/cache/8068a4d732d1847a062d97696687b38f.png" alt="8068a4d732d1847a062d97696687b38f">
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<div class="title">Figure 4. Principle Structure of a Parameter Catalog</div>
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<p>The diagram models four types of technical components whose data shall be stored in the catalog, e.g. for parameterization of simulation models later: <em>Boiler</em>, <em>CombinedHeatPower</em>, <em>SolarPanel</em>, and <em>Inverter</em>.</p>
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<p>The catalog itself is represented by class <em>EnergyComponentsCatalog</em>.
Unlike dozens, hundreds, or even thousands of objects to be cataloged&#8201;&#8212;&#8201;Boilers, Inverters etc.&#8201;&#8212;&#8201;there will be just exactly <strong>one</strong> catalog object in the data representing the catalog itself.
Its "singularity" is not visible in the class diagram, but an <em>Ecore</em> convention requires that all objects must form a composition hierarchy with only one root object.</p>
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<div class="paragraph">
<div class="title">Composition</div>
<p>If, in the domain, one object is composed of others, this is expressed by a special kind of association called <em>composition</em>.
Compositions are depicted as a link with a diamond shape attached to the containing object. In the <em>Boiler</em> case said link translates to: The <em>EnergyComponentsCatalog</em> contains&#8201;&#8212;&#8201;or is composed of&#8201;&#8212;&#8201;zero or more (<code>0..*</code>) boiler objects stored in a list named <code>boilers</code>.</p>
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<p>Note that class names&#8201;&#8212;&#8201;despite the fact that they model a set of similar objects&#8201;&#8212;&#8201;are always written in <em>singular</em>! They are written in <a href="https://en.wikipedia.org/wiki/Camel_case">Camel case notation</a> starting with an upper case letter. Associations and attributes are written the same way, but starting with a lower case letter. Names for list-like associations and attributes usually are written in plural form.</p>
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<div class="title">Inheritance</div>
<p>Besides composition of <strong>objects</strong>, the model above shows another, completely different, kind of hierarchy: the inheritance hierarchy between <strong>classes</strong>.
Whenever classes of objects share the same attributes or associations, we don&#8217;t like to repeat ourselves by adding that attribute or relation to all classes again and again.
Instead, we add a <em>super class</em> to define common attributes and associations and connect it to <em>sub classes</em> that will automatically <em>inherit</em> all the features of their super class.</p>
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<p>In our example above, common to all four energy components are attributes <code>modelName</code> and <code>revisionYear</code>, thus these are modeled by class <code>EnergyComponent</code> that is directly or indirectly a super class of <em>Boiler</em>, <em>CombinedHeatPower</em>, <em>SolarPanel</em>, and <em>Inverter</em>.
Similar, <em>Boiler</em> and <em>CombinedHeatPower</em> share attribute <code>installedThermalPower</code> factored out by class <em>ChemicalEnergyDevice</em>.</p>
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<div class="title">Associations</div>
<p>You probably noticed a fifth type of objects contained in the catalog, namely <code>Manufacturer</code> objects stored in list <code>manufactureres</code>.
How come? Ok, here is the story:</p>
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<div class="title">Domain Expert Meets Developer</div>
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<p><em>Exp</em>: &#8220;I&#8217;d like to store a component&#8217;s manufacturer. Shall I add a String attribute <code>manufacturerName</code> to all classes like <em>Boiler</em>, <em>Inverter</em> and so on to store the manufacturer&#8217;s name?&#8221;</p>
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<p><em>Dev</em> shudders: &#8220;Well, what do you mean by "&#8230;&#8203; and so on"?&#8221;</p>
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<p><em>Exp</em>: &#8220;Basically, I mean all energy components.&#8221;</p>
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<p><em>Dev</em>: &#8220;Fine. We already have a class representing all those energy components, brilliantly named <em>EnergyComponent</em>. Thus, we can define <code>manfacturerName</code> there, following one of Developer&#8217;s holy principles: "<em>DRY</em>&#8201;&#8212;&#8201;Don&#8217;t repeat yourself!"
By the way: Is the name all you want to know about manufacturers?&#8221;</p>
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<p><em>Exp</em>: &#8220;Mhm, maybe we need to know if they are still in business &#8230;&#8203;&#8221;</p>
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<p><em>Dev</em>: &#8220;&#8230;&#8203; or even since when they were out of business, if at all &#8230;&#8203;&#8221;</p>
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<p><em>Exp</em>: &#8220;&#8230;&#8203; and the country or region they are active.&#8221;</p>
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<p><em>Dev</em>: &#8220;Ok, so it&#8217;s not just the name&#8201;&#8212;&#8201;we need a class <code>Manufacturer</code> to model all these information.&#8221;</p>
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<p><em>Exp</em> sighs.</p>
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<p><em>Dev</em>: &#8220;Come on, its not that hard to add a class to our data model, isn&#8217;t it?&#8221;</p>
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<p><em>Exp</em>: &#8220;Ok, but how can we express what components a manufacturer produces?&#8221;</p>
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<p><em>Dev</em>: &#8220;Wasn&#8217;t it the other way around? I thought, you just wanted to know the manufacturer of a component?&#8221;</p>
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<p><em>Exp</em>: &#8220;What is the difference?&#8221;</p>
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<p><em>Dev</em>: &#8220;In data modeling, it is the difference between a uni-directional and a bi-directional association.&#8221;</p>
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<p><em>Exp</em>: &#8220;&#8230;&#8203;?&#8221;</p>
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<p><em>Dev</em>: &#8220;Let&#8217;s put it that way: The difference between a link with an arrow on one side or on both sides.&#8221;</p>
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<p><em>Exp</em>: &#8220;Ok. We don&#8217;t need a list of components per manufacturer, but simply a reference from the component to its manufacturer.&#8221;</p>
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<p><em>Dev</em>: &#8220;Fine, then in Ecore please create a simple reference from class <code>EnergyComponent</code> to class <code>Manufacturer</code>, maybe named <code>producedBy</code>.&#8221;</p>
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<p><em>Exp</em>: &#8220;I will try this and get back to you.&#8221;</p>
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<p><em>Dev</em>: &#8220;Fine &#8230;&#8203; good meeting.&#8221;</p>
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<p>Observe in our data model, reference <code>producedBy</code> points <em>from</em> <code>EnergyComponent</code> <em>to</em> <code>Manufacturer</code> making it uni-directional reference.
One can simply query the manufacturer of a product, but not so the other way around.
With a bi-directional reference both queries would be available.</p>
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<p>Observe also the annotations <code>0..*</code> and <code>1..1</code> near class <code>Manufacturer</code>.
These are <em>multiplicities</em> of associations: An <code>EnergyComponentsCatalog</code> contains zero, one, or many objects of class <code>Manufacturer</code> and an <code>EnergyComponent</code> must reference exactly one manufacturer&#8201;&#8212;&#8201;not less, not more.</p>
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<img src="ParameterCatalogs2Images/EcoreRelations.gif" alt="EcoreRelations" width="200">
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<div class="title">Figure 5. Ecore Relations</div>
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<p>To recapitulate: Our example parameter catalog already exhibits all four types of relations provided by Ecore.
You find these in the Ecore editor&#8217;s palette shown here.
To create a relation between a sub class and a super class use tool <code>SuperType</code>.
Use the other tools to create an association between classes, may it be a simple (uni-directional) reference, a bi-directional reference, or a composition.</p>
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<div class="title">Attributes and Enumerations</div>
<p>Obviously, attributes are central in data modeling.
Create one by dragging it from the palette onto our one and only class so far: <code>EnergyComponentsCatalog</code>.
The class symbol will turn red to indicate an error.
Hover with the mouse pointer over the new attribute and a tooltip with a more or less helpful error message will appear.
Current error is caused by that no data type was set for the new attribute.
Data types for attributes can be integer or floating point numbers, strings, dates, booleans, and more.
To get rid of the error:</p>
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<p>If not already selected, select new attribute by clicking at it in the editor.</p>
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<p>In view <em>Properties</em> find <code>EType</code> and click button <code>&#8230;&#8203;</code> to see a quite long list of available data types.</p>
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<p>Choose <code>EString [java.lang:String]</code> from the list and the error is gone.</p>
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<img src="ParameterCatalogs2Images/EcoreClassWithAttribute.png" alt="EcoreClassWithAttribute" width="200">
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<div class="title">Figure 6. Class with Attribute</div>
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<p>Change the attribute&#8217;s name to <code>author</code> and the class should look like shown here.</p>
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<p>Most data types to choose from begin with letter <strong>E</strong> like in <strong>E</strong>core.
These are just Ecore enabled variants of the respective Java types, thus, choose EInt for an int, EFloat for a 32 bit floating point number, EDouble for a 64 bit one, and so on.</p>
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<p>Ecore allows to introduce new data types.
We employ this feature later to enable data models with physical units and quantities.</p>
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<p>There exists one other means to define the values an attribute can take, namely enumerations of distinct literals. Take <em>Monday</em>, <em>Tuesday</em>, <em>Wednesday</em>, &#8230;&#8203; as a typical example for representing weekdays.
In our example data model you&#8217;ll find one <em>Enumeration</em> named <code>BoilerType</code> with values <code>LowTemperature</code> and <code>Condensing</code>.</p>
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<div class="title">Homework</div>
<p>The next section deals with generation of Java code from data models. To have more to play with, please implement our example model in Ecore now.</p>
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<img src="ParameterCatalogs2Images/EcoreClassifier.png" alt="EcoreClassifier" width="200">
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<div class="title">Figure 7. Abstract Class</div>
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<p>To do this, there is one more thing to know about classes: the difference between ordinary classes and abstract classes.
'Ordinary class' doesn&#8217;t sound nice, therefore, classes that are not abstract are called <em>concrete</em> classes.
Our example diagram depicts abstract classes with letter <strong>A</strong> while concrete classes are labeled with <strong>C</strong>. You add abstract classes to a model with a special palette tool shown here.</p>
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<p>The thing is: Objects can be created for concrete classes only!</p>
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<p>In our example, it makes no sense to create an object from class <em>EnergyComponent</em>, because there is not such a thing like an energy component <em>per se</em>.
Therefore, this class is <em>abstract</em>.
It is true that an inverter <em>is</em> an energy component, thus inheriting all its features, but it was <em>created</em> as <em>Inverter</em>, not as <em>EnergyComponent</em>.</p>
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<p>Super classes will be abstract most of the time.
So my advice is: Model a super class as abstract class unless you convince yourself that there exist real objects in the domain that belong to the super class but, at the same time, do not belong to any of its sub classes.
In the Ecore editor properties view, you can specify if a class is abstract or not, simply by toggling check box <code>Abstract</code>.</p>
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<p>Two more tips and you are ready to rock and roll!&#8201;&#8212;&#8201;At least with your homework.</p>
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<p>An exhaustive user manual for Ecore diagram editor is available. Execute <code>Help &#8594; Welcome</code> and follow link <code>Learn how to use the diagram editor</code>.</p>
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<p>If Ecore models get bigger, you may find it more convenient to work with a form based UI instead of, or in addition to, the diagram editor.
Open this kind of editor via command <code>Open With &#8594; Ecore Editor</code> from the context menu over entry <code>democatalog.ecore</code> in the <em>Model Explorer</em> view.
Note that Eclipse synchronizes different editors of the same content automatically.</p>
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<h3 id="truegeneration-of-java-code-from-data-model"><a class="anchor" href="#truegeneration-of-java-code-from-data-model"></a>Generation of Java Code from Data Model</h3>
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<p>By now, your Ecore model should look like this:</p>
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<div class="title">Figure 8. Example Model (Homework)</div>
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<p>Let us bring the model to life, that is, generate code from it that creates, reads, updates, and deletes concrete data objects of modeled classes in computers.
I would like to tell you that this is done with just one click but, actually, you need two or three:</p>
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<p>Make sure all files are saved (<code>File &#8594; Save All</code>)</p>
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<p>Execute <code>Generate &#8594; Model Code</code> from context menu over <code>democatalog.ecore</code></p>
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<p>Execute <code>Generate &#8594; Edit Code</code> from context menu over <code>democatalog.ecore</code></p>
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<p>Please do <strong>not</strong> execute <code>Generate &#8594; All</code> or <code>Generate &#8594; Editor Code</code>.</p>
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<img src="ParameterCatalogs2Images/GenerateMenu.png" alt="GeneratedClasses" width="260">
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<p>This would create code for a simple user interface, but we use more advanced EMF Forms for that later.
If, by mistake, project <code>demo.catalog.editor</code> was created, just delete it from <em>Model Explorer</em> and do not forget to check <code>Delete project contents on disk</code> in confirmation dialog.</p>
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<div class="title">Figure 9. Generated Classes</div>
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<p><code>Generate &#8594; Model Code</code> creates classes that represent the modeled data in code. These classes are located in three packages under directory <code>src-gen</code> in <code>demo.catalog</code>.</p>
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<p><code>Generate &#8594; Edit Code</code> creates a whole new Eclipse project named <code>demo.catalog.edit</code>, again with generated classes under directory <code>src-gen</code>.</p>
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<p>You may have a look at some Java classes for curiosity by double clicking at them in <em>Model Explorer</em>. There is no point in trying to understand the code in detail, but observe token <code>@generated</code> present in the comments of all classes, fields and methods. Classes, fields and methods marked with this token are (re)generated whenever above commands are executed.</p>
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<p>Sometimes it maybe required to manually adapt generated code&#8201;&#8212;&#8201;after all our concern is "low code", not "no code" development. In that case, we will replace <code>@generated</code> by <code>@generated NOT</code> to prevent code regeneration.</p>
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<p>After code generation, you may have noticed some warnings showed up in view <em>Problems</em>.</p>
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<img src="ParameterCatalogs2Images/Warnings.gif" alt="Warnings" width="500">
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<div class="title">Figure 10. Warnings</div>
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<p>In general, it is highly recommended to resolve warnings, and errors of course, but we will make an exception from the rule, since the warnings are uncritical and would reappear each time code is regenerated.</p>
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<h3 id="truegeneration-and-tweaking-of-user-interface"><a class="anchor" href="#truegeneration-and-tweaking-of-user-interface"></a>Generation and Tweaking of User Interface</h3>
<div class="paragraph">
<p>In this section you will learn how to generate and tweak a CRUD user interface based on Ecore data model and Java classes created for our demo parameters catalog above. Topics described here are discussed in more detail in tutorial <a href="https://eclipsesource.com/blogs/tutorials/getting-started-with-EMF-Forms/">Getting started with EMF Forms</a>.
To find out what user interface controls and layouts are provided by this framework have a look at <a href="https://eclipsesource.com/blogs/tutorials/emf-forms-view-model-elements/">EMF Forms – View Model Elements</a>. <em>EMF Forms</em> is already part of package <em>Eclipse Modeling Tools</em>, so we can create a third Eclipse project/plugin that implements a user interface for editing catalog data without further ado:</p>
</div>
<div class="olist arabic">
<ol class="arabic">
<li>
<p>From context menu over <code>democatalog.ecore</code> execute <code>EMF Forms &#8594; Create View Model Project</code></p>
</li>
<li>
<p>Leave project name <code>demo.catalog.viewmodel</code> as is but uncheck <code>Use default location</code>&#8201;&#8212;&#8201;as we always do&#8201;&#8212;&#8201;and browse to the directory containing <code>demo.catalog</code></p>
</li>
<li>
<p>Click <code>Next &gt;</code> and select <code>EnergyComponentsCatalog</code> as data element we want to create a user interface for</p>
</li>
<li>
<p>Leave <code>Fill view model with default layout</code> checked and click <code>Finish</code>.</p>
</li>
</ol>
</div>
<div class="paragraph">
<p>According to these inputs a new project is created with file <code>EnergyComponentsCatalog.view</code> under directory <code>view models</code>.
This file opens automatically in a special <em>View Editor</em>.</p>
</div>
<div class="imageblock thumb">
<div class="content">
<img src="ParameterCatalogs2Images/ViewModel.png" alt="ViewModel1">
</div>
<div class="title">Figure 11. New View Model</div>
</div>
<div class="paragraph">
<p>Like the <strong>data</strong> of our catalog are modeled as Ecore file using a dedicated graphical editor, so will our catalog’s <strong>user interface</strong> be modeled in <code>.view</code> files, again using a special editor.</p>
</div>
<div class="paragraph">
<p>Since we opted for <code>Fill view model with default layout</code> the catalog&#8217;s UI is filled initially with default controls for all data items assigned to Ecore type <code>EnergyComponentsCatalog</code> like a string control for <code>author</code> or list controls for <code>boilers</code>, <code>chps</code>, and so on.</p>
</div>
<div class="paragraph">
<p>See red arrow in the above screen-shot?
It points to a button that opens a functional preview of the modeled user interface.</p>
</div>
<div class="imageblock thumb">
<div class="content">
<img src="ParameterCatalogs2Images/ViewEditorPreview.png" alt="ViewModel1" width="500">
</div>
<div class="title">Figure 12. User Interface Preview</div>
</div>
<div class="admonitionblock tip">
<table>
<tr>
<td class="icon">
<i class="fa icon-tip" title="Tip"></i>
</td>
<td class="content">
<div class="paragraph">
<p>Double click on tab <em>EMF Forms Preview</em> to enlarge view for better handling&#8201;&#8212;&#8201;double click again to get back.</p>
</div>
<div class="paragraph">
<p>Enable auto refresh mode <span class="image"><img src="ParameterCatalogs2Images/ViewModelAutomaticRefresh.gif" alt="ViewModelAutomaticRefresh" width="40"></span> to let each change in the view model instantly be reflected in the preview.</p>
</div>
<div class="paragraph">
<p>Given your screen is big enough, you may want to dock-out the preview by dragging tab <em>EMF Forms Preview</em> out of Eclipse&#8217;s main window.
Seeing editor and preview side by side is a great way to explore the possibilities of view models.</p>
</div>
</td>
</tr>
</table>
</div>
<div class="paragraph">
<p>Red input field and exclamation mark in the preview signal missing or inconsistent data.
Ecore data model specifies attribute <code>author</code> with a lower bound of one, meaning it is a mandatory attribute.
As soon as an author&#8217;s name is provided, the error indication disappears.
This is what <em>functional</em> preview means.
You can even create new boilers or other objects in lists provided, with all forms created "automagically" with respect to our underlying Ecore data model.</p>
</div>
<div class="paragraph">
<p>Of course, such automatic approach has its limits.
In our case, to have a long list of lists is not very user-friendly, because one has to scroll up and down to find a specific list.
Also, no specific object data are shown in the list and data can only be edited in a pop-up form (no inline editing).</p>
</div>
<div class="paragraph">
<p>How should a better UI look and feel like?</p>
</div>
<div class="paragraph">
<p>If there are many lists (types) of entities&#8201;&#8212;&#8201;the normal case for parameter catalogs&#8201;&#8212;&#8201;users should select what list they want to work with by selecting it from a list or tree view that is always visible, the <em>master view</em>.
Once a type is selected in the master view, a table with all objects of this list/type shall appear sidelong in a <em>detail view</em>, ready for editing.</p>
</div>
<div class="paragraph">
<p>In <em>EMF Forms</em> master-detail-views can be modeled either with <em>Categorization</em> or <em>Tree Master Detail</em> UI components.
The latter not only allows to edit information displayed in the detail view, but also the tree of elements in the master view.
Opposed to that, a <em>Categorization</em> presents a fixed hierarchy of elements to choose from.
This is exactly what we need as there are only a fixed number of types of objects to be edited in a parameters catalog.</p>
</div>
<div class="sect3">
<h4 id="trueadding-tables-to-the-ui"><a class="anchor" href="#trueadding-tables-to-the-ui"></a>Adding Tables to the UI</h4>
<div class="openblock float-group">
<div class="content">
<div class="imageblock right thumb">
<div class="content">
<img src="ParameterCatalogs2Images/ViewModelDeleteControls.gif" alt="ViewModelDeleteControls" width="300">
</div>
<div class="title">Figure 13. Delete default list controls</div>
</div>
<div class="paragraph">
<p>But first, we replace the default controls for lists of boilers, chps, and so on by tables. As shown here, select all list controls in the view model and execute <code>Delete</code> from context menu. Refresh <em>View Editor Preview</em> to verify that only field <code>Author*</code> is left.</p>
</div>
</div>
</div>
<div class="openblock float-group">
<div class="content">
<div class="imageblock right thumb">
<div class="content">
<img src="ParameterCatalogs2Images/ViewModelCreateTable.gif" alt="ViewModelCreateTable" width="300">
</div>
<div class="title">Figure 14. Create Table Control</div>
</div>
<div class="paragraph">
<p>Next, create a table that shall display all boilers in a catalog:
Select <code>EnergyComponentsCatalog</code>, activate context menu and choose <code>TableControl</code> from the list of available UI elements.
(EnergyComponentsCatalog represents the root view of the UI and, as such, accepts quite a lot of different UI components as child components.)</p>
</div>
<div class="paragraph">
<p>Entry <code>TableControl</code> was inserted into the list of interface elements below <code>Control author</code>.
Checking updated preview reveals no table but a message basically saying that a reference to the domain model is missing, in other words: <em>EMF Forms</em> does not know yet what data to present in table.
Click on entry <code>TableControl</code> to see its details.
A red exclamation mark indicates the missing <code>Domain Model Reference*</code>.
Click on <span class="image"><img src="ParameterCatalogs2Images/ButtonLinkPlus.gif" alt="ButtonLinkPlus" width="40"></span> and be ready to chase a sequence of dialogs:</p>
</div>
</div>
</div>
<div class="olist arabic">
<ol class="arabic">
<li>
<p>Click on another <span class="image"><img src="ParameterCatalogs2Images/ButtonLinkPlus.gif" alt="ButtonLinkPlus" width="40"></span> in dialog <code>Configure TableDomainModelReference</code></p>
</li>
<li>
<p>In wizard <code>New Reference Element</code> select <code>model &#8594; FeaturePathDomainModelReference</code> and click <code>Next &gt;</code></p>
</li>
<li>
<p>Click <code>Link Domain Model EFeature</code> and in appearing pop-up list choose reference to list of objects you want to edit in the table, e.g. <code>boilers</code>; confirm with <code>OK</code> safely ignoring warning about missing <code>PropertyDescriptor</code>.</p>
</li>
<li>
<p><code>Finish</code> wizard <code>New Reference Element</code></p>
</li>
<li>
<p><code>Finish</code> dialog <code>Configure TableDomainModelReference</code>.</p>
</li>
</ol>
</div>
<div class="paragraph">
<p>This was some work, but as reward we get a fully specified table control in <em>View Editor</em> that "translates" into a preview where we can create, read, update, and delete boilers.</p>
</div>
<div class="imageblock thumb">
<div class="content">
<img src="ParameterCatalogs2Images/ViewModelWithTable.gif" alt="ViewModelWithTable.gif">
</div>
<div class="title">Figure 15. Table for Boilers</div>
</div>
<div class="paragraph">
<p>Moreover, clicking at a table header sorts all objects in it (rows) according to the values in this column.
Column widths can adapted, too.</p>
</div>
<div class="openblock float-group">
<div class="content">
<div class="imageblock right thumb">
<div class="content">
<img src="ParameterCatalogs2Images/ViewModelTweakTable.gif" alt="ViewModelTweakTable" width="300">
</div>
<div class="title">Figure 16. Modify Table Control</div>
</div>
<div class="paragraph">
<p>Table UIs can be tweaked in many ways, e.g. selection and sequence of columns can be declared via list <code>Column Domain Model References</code>. To fill this list with defaults, execute <code>Generate Columns</code> from table control&#8217;s context menu. Reorder them as you like or delete columns that are not important to the user.</p>
</div>
<div class="paragraph">
<p>Notice here an important overall feature of <em>EMF Forms</em>: If something is left unspecified, be it the view model for an Ecore object type or the specification of table columns, <em>EMF Forms</em> will always find a default solution! Applied to columns specification this means we get default columns automatically back in the moment the last column is removed from list <code>Column Domain Model References</code>.</p>
</div>
<div class="paragraph">
<p>If explicit column specifications are present further configurations can be added to a table control from its context menu, e.g. initial column widths or read-only status of columns. See <a href="https://eclipsesource.com/de/blogs/2018/01/31/emf-forms-1-15-0-feature-enhanced-table-renderer/">here</a> for details.</p>
</div>
</div>
</div>
<div class="paragraph">
<p>By default only attributes are displayed and directly editable in tables while references to other objects&#8201;&#8212;&#8201;in our case the reference to a manufacturer&#8201;&#8212;&#8201;are not.</p>
</div>
<div class="openblock float-group">
<div class="content">
<div class="imageblock right thumb">
<div class="content">
<img src="ParameterCatalogs2Images/ViewModelWithPanel.gif" alt="ViewModelWithPanel" width="300">
</div>
<div class="title">Figure 17. Default  Panel for Boilers</div>
</div>
<div class="paragraph">
<p>To get the default (<em>sic!</em>) editing panel for an selected table row, in <em>View Editor</em> just set <code>Detail Editing*</code> from <code>None</code> to <code>WithPanel</code>, <strong>press <em>Tab</em></strong>, and save. For boilers, <em>EMF Forms</em> will create the editing panel shown here. Regardless wether users edit data in the panel or directly in the table&#8201;&#8212;&#8201;both will stay in sync any time.</p>
</div>
</div>
</div>
<div class="admonitionblock warning">
<table>
<tr>
<td class="icon">
<i class="fa icon-warning" title="Warning"></i>
</td>
<td class="content">
<div class="paragraph">
<p><em>View editor</em> exhibits an irritating behavior: With preview auto-refresh turned on, any change in the details view is reflected instantly in the preview, even without saving the form or leaving the edited field.</p>
</div>
<div class="paragraph">
<p>On the other hand, <strong>saving</strong> an updated view editor only takes into account edited fields after they have lost focus, e.g. by pressing <em>Tab</em> key or clicking with the mouse into another field.
So, saving a form before the focus has shifted from the last edited field won&#8217;t honor this edit, that is you won&#8217;t necessarily get what you see.</p>
</div>
</td>
</tr>
</table>
</div>
<div class="paragraph">
<p>One last thing: Enter <code>boilers</code> as name for the table control so we can distinguish it from the other four table controls to come.</p>
</div>
<div class="paragraph">
<p>Yes! &#8230;&#8203; Please repeat above procedure to create table controls for chps, solar panels, inverters and manufacturers, too. I did this in about 3 minutes. ;-)</p>
</div>
</div>
<div class="sect3">
<h4 id="truemaster-detail-view-with-categories"><a class="anchor" href="#truemaster-detail-view-with-categories"></a>Master-Detail View with Categories</h4>
<div class="paragraph">
<p>In last section we improved our catalog&#8217;s UI by replacing simple object lists by tables that can be sorted, customized and edited inline as well as in an associated panel.
Alas, instead a list of lists we have got an even bigger list of tables.</p>
</div>
<div class="paragraph">
<p>High time to introduce a master-detail view that presents categories of object types in a master view and, after one is selected, the according object table as detail.</p>
</div>
<div class="openblock float-group">
<div class="content">
<div class="imageblock right thumb">
<div class="content">
<img src="ParameterCatalogs2Images/ViewModelCatgorization1.gif" alt="ViewModelCatgorization1" width="180">
</div>
<div class="title">Figure 18. Category Tree</div>
</div>
<div class="paragraph">
<p>Add a <em>Categorization</em> view to the list of UI elements in <em>View Editor</em> by selecting <code>EnergyComponentsCatalog</code> and choose <code>Categorization</code> from its contect menu.</p>
</div>
<div class="paragraph">
<p>Now add two <code>Composite Category</code> elements and one <code>Leaf Category</code> to <code>Categorization</code> from according context menu. This gives us three top level entries in the hierarchy.</p>
</div>
<div class="paragraph">
<p>In the same way add two <code>Leaf Category</code> elements to each <code>Composite Category</code> resulting in the hierarchy depicted here.</p>
</div>
</div>
</div>
<div class="openblock float-group">
<div class="content">
<div class="imageblock right thumb">
<div class="content">
<img src="ParameterCatalogs2Images/ViewModelCatgorization2.gif" alt="ViewModelCatgorization2" width="260">
</div>
<div class="title">Figure 19. Completed View Model</div>
</div>
<div class="paragraph">
<p>This screen shot shows the view model of our UI when finished. To get there:</p>
</div>
<div class="olist arabic">
<ol class="arabic">
<li>
<p>Select UI element <code>Categorization</code> and rename it to <code>Categories</code></p>
</li>
<li>
<p>Rename composite and leaf categories as depicted here</p>
</li>
<li>
<p>Drag all table controls one by one into the suited leaf category</p>
</li>
<li>
<p>Confirm master-detail view works as expected in the preview.</p>
</li>
</ol>
</div>
</div>
</div>
<div class="admonitionblock important">
<table>
<tr>
<td class="icon">
<i class="fa icon-important" title="Important"></i>
</td>
<td class="content">
<div class="paragraph">
<p>The UI hierarchy to access tables for entity types is independent, and usually will differ, from aggregation and inheritance hierarchies present in Ecore data model (compare fig. <a href="#fig-example-model">Example Model</a>).</p>
</div>
</td>
</tr>
</table>
</div>
<div class="paragraph">
<p>Note that <em>EMF Forms Preview</em> provides these buttons <span class="image"><img src="ParameterCatalogs2Images/ViewModelPersistence.gif" alt="PreviewPersistanceButtons" width="68"></span> to clear, load and store edited data.
In fact, this feature gives us a fully functional prototype.
At least during refinement of model and UI, data sets can be created, edited, and tested for usability without the need to built a full blown, deployable application&#8201;&#8212;&#8201;see parts <em>Accessing and Using Parameter Catalogs</em> and <em>Build (Parameter Catalog) Applications with Eclipse Tycho</em> below.</p>
</div>
<div class="paragraph">
<p>Be aware that in some cases the view model must adapt to changes in the data model, e.g. a new leaf category and table component has to be created for a new catalog object type.
Other changes are automatically reflected in the generated UI, at least for default forms and other UI elements.
To our convenience, view model specifications incompatible with data model are indicated by error badges in the <em>View Editor</em>.</p>
</div>
<div class="paragraph">
<p>Changes in data model also can make existing XML data incompatible. There are tools for data migration, but for now, recreation of test data or manual editing of XML file is the way to go.</p>
</div>
</div>
<div class="sect3">
<h4 id="truesummary"><a class="anchor" href="#truesummary"></a>Summary</h4>
<div class="paragraph">
<p>What have we achieved so far?</p>
</div>
<div class="paragraph">
<p>We created a graphical Ecore data model with a catalog class and five classes/types of objects therein.
Classes have been defined by name, attributes, and relations between, often with cardinalities.
Whenever classes shared some attributes or references we factored these out into super classes.
An enumeration introduced a new attribute type from a set of named values.</p>
</div>
<div class="paragraph">
<p>From this data model, we issued commands to create matching Java code for representing the data in memory as well as to store and retrieve them on and from disk. Methods to create, read, update and delete data objects (CRUD) were generated, too.</p>
</div>
<div class="paragraph">
<p>Lastly, we thought about a good user interface for this data and used <em>EMF Forms</em> to model and prototype it.</p>
</div>
</div>
</div>
<div class="sect2">
<h3 id="truebonus-solutions-for-specific-modeling-problems"><a class="anchor" href="#truebonus-solutions-for-specific-modeling-problems"></a>Bonus: Solutions for Specific Modeling Problems</h3>
<div class="sect3">
<h4 id="trueadd-units-to-the-mix"><a class="anchor" href="#trueadd-units-to-the-mix"></a>Add Units to the Mix</h4>
<div class="paragraph">
<p><strong>TBD</strong></p>
</div>
<div class="paragraph">
<p>As mentioned earlier, parameter catalogs for simulations should be able to represent quantities, not just bare integer and real numbers.</p>
</div>
<div class="paragraph">
<p>using Indrya, the reference implementation for Units of Measurement in Java (JSR 385)</p>
</div>
<div class="paragraph">
<p>To this end, the author has created two Eclipse plug-in projects providing this feature to be used by Ecore and EMF Forms.</p>
</div>
<div class="paragraph">
<p>Third-party libraries like Indrya, usually, are not distributed as plug-ins, but <em>Tycho</em> can wrap them automatically as OSGi plug-ins that can added directly to our application.</p>
</div>
<div class="paragraph">
<p>Another plug-in, created by the author connects the Ecore and Indrya. We will compile it from source code, simply by importing the projects.</p>
</div>
<div class="olist arabic">
<ol class="arabic">
<li>
<p>Copy to file system &#8230;&#8203;</p>
</li>
<li>
<p>Import project but <strong>not</strong> copying it in the workspace (just linking)</p>
</li>
</ol>
</div>
</div>
<div class="sect3">
<h4 id="truerepresent-functions-in-a-parameter-catalog"><a class="anchor" href="#truerepresent-functions-in-a-parameter-catalog"></a>Represent Functions in a Parameter Catalog</h4>
<div class="paragraph">
<p><strong>TBD</strong></p>
</div>
<div class="paragraph">
<p>for creating custom UI labels:</p>
</div>
<div class="ulist">
<ul>
<li>
<p><code>ExponentialFunctionItemProvider.java</code></p>
</li>
<li>
<p><code>LinearFunctionItemProvider.java</code></p>
</li>
<li>
<p><code>TableFunctionItemProvider.java</code></p>
</li>
</ul>
</div>
<div class="paragraph">
<p>Custom code marked with <code>@generated NOT</code> in <code>de.hftstuttgart.energycomponents.provider</code> in project <code>de.hftstuttgart.energycomponents.edit</code></p>
</div>
</div>
<div class="sect3">
<h4 id="truehow-to-model-derived-references-and-attributes"><a class="anchor" href="#truehow-to-model-derived-references-and-attributes"></a>How to Model Derived References and Attributes</h4>
<div class="paragraph">
<p><strong>TBD</strong></p>
</div>
<div class="paragraph">
<p>We haven&#8217;t used derived references or attributes by now. But if one has to implement some by providing a getter, it is necessary to return an unmodifiable list like BasicEList.UnmodifiableEList or EcoreUtil.unmodifiableList(&#8230;&#8203;) instead of EList as described here: <a href="https://www.ntnu.no/wiki/plugins/servlet/mobile?contentId=112269388#content/view/112269388" class="bare">https://www.ntnu.no/wiki/plugins/servlet/mobile?contentId=112269388#content/view/112269388</a> .</p>
</div>
<div style="page-break-after: always;"></div>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="trueaccessing-and-using-parameter-catalogs"><a class="anchor" href="#trueaccessing-and-using-parameter-catalogs"></a>Accessing and Using Parameter Catalogs</h2>
<div class="sectionbody">
<div class="sect2">
<h3 id="trueaccessing-xml-catalogs"><a class="anchor" href="#trueaccessing-xml-catalogs"></a>Accessing XML-Catalogs</h3>
<div class="paragraph">
<div class="title">Add Ecore data model to a third-party Java application</div>
<p><strong>TBD</strong></p>
</div>
<div class="literalblock">
<div class="content">
<pre>import java.util.Collection;
import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.ResourceSet;
import org.eclipse.emf.ecore.resource.impl.ResourceSetImpl;
import org.eclipse.emf.ecore.util.EcoreUtil;
import de.hftstuttgart.energycomponents.EnCompPackage;
import de.hftstuttgart.energycomponents.HeatPump;</pre>
</div>
</div>
<div class="literalblock">
<div class="content">
<pre>ResourceSet resSet = new ResourceSetImpl();
Resource resource = resSet.getResource(URI.createURI("catalog.xml"), true);
Collection&lt;HeatPump&gt; allHeatPumps = EcoreUtil.getObjectsByType(
		resource.getContents(), EnCompPackage.eINSTANCE.getHeatPump());</pre>
</div>
</div>
<div class="paragraph">
<p>catalog.xml muss durch den richtigen Pfad zum XML-Katalog ersetzt werden.</p>
</div>
<div class="paragraph">
<div class="title">Load XML Data Catalog and Access Corresponding Java Objects in Code</div>
<p><strong>TBD</strong></p>
</div>
<div class="paragraph">
<div class="title">Access from Python?</div>
<p><strong>TBD</strong></p>
</div>
</div>
<div class="sect2">
<h3 id="truecreate-insel-models-with-handlebars-templates"><a class="anchor" href="#truecreate-insel-models-with-handlebars-templates"></a>Create Insel Models with Handlebars Templates</h3>
<div class="paragraph">
<p>Handlebar templates to access data catalogs and create/parameterize textual simulation models.</p>
</div>
<div class="paragraph">
<div class="title">Parameterization of blocks</div>
<p><strong>TBD</strong></p>
</div>
<div class="paragraph">
<div class="title">Creation of submodels, e.g. computing parameterized functions</div>
<p><strong>TBD</strong></p>
</div>
<div style="page-break-after: always;"></div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="truebuild-parameter-catalog-applications-with-eclipse-tycho"><a class="anchor" href="#truebuild-parameter-catalog-applications-with-eclipse-tycho"></a>Build (Parameter Catalog) Applications with Eclipse Tycho</h2>
<div class="sectionbody">
<div class="paragraph">
<p>Three plugins so for for the content and UI.</p>
</div>
<div class="paragraph">
<p>Missing: Deployable application and inclusion to third party libraries.</p>
</div>
<div class="paragraph">
<p>Building an application "around" the three plugins for Ecore data model and UI specification model.</p>
</div>
<div class="paragraph">
<p>See template.</p>
</div>
<div class="sect2">
<h3 id="truecreate-an-eclipse-application"><a class="anchor" href="#truecreate-an-eclipse-application"></a>Create an Eclipse Application</h3>
<div class="paragraph">
<p><strong>TBD</strong></p>
</div>
</div>
<div class="sect2">
<h3 id="trueuse-maven-and-tycho-as-build-system"><a class="anchor" href="#trueuse-maven-and-tycho-as-build-system"></a>Use Maven and Tycho as Build System</h3>
<div class="paragraph">
<div class="title">Install Maven Support</div>
<p>We are going to create a complete Eclipse desktop application from generated code.
We also want to deploy this application for Linux, macOS and Windows operating systems.
Eclipse offers several approaches for compiling and deploying such an application, traditionally with <em>Ant</em> scripts.</p>
</div>
<div class="paragraph">
<p>Creation and maintenance of these scripts turned out to be tedious and error prone.
For quite some years now, the proposed&#8201;&#8212;&#8201;and mostly supported&#8201;&#8212;&#8201;method for building Eclipse applications is to use <em>Maven</em> build system, more specifically, a couple of Maven plug-ins, subsumed under the name <em>Tycho</em>.</p>
</div>
<div class="paragraph">
<p>Many Eclipse platforms have Maven support <a href="https://www.eclipse.org/m2e/"><em>M2Eclipse</em></a> already built in, not so our <em>Eclipse Modeling Tools</em>.
But don&#8217;t worry: Installation of required Eclipse feature is easy and straight forward.
And, by the way, you will acquire the indispensable skill of how to install new plug-ins/features to Eclipse.</p>
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<p>First, tell your Eclipse installation where to look for the new software.
Execute <code>Help &#8594; Install new Software&#8230;&#8203;</code> to invoke dialog <em>Available Software</em> and press <code>Add&#8230;&#8203;</code>.
Sub-dialog <code>Add Repository</code> pops up.</p>
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<img src="ParameterCatalogs2Images/InstallMaven1.gif" alt="InstallMaven1">
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<div class="title">Figure 20. Add update site m2e</div>
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<p>In there provide <code>m2e</code> as name and</p>
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<div class="content">
<pre>http://download.eclipse.org/technology/m2e/releases</pre>
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