This repository contains instructions on how to install Eclipse and Xtext as well as how to create a new Xtext project. Moreover, it contains the source code of two exemplary domain-specific modeling languages implemented with the Eclipse Xtext language workbench: Entity DSL and State Machine DSL.
First, download Eclipse Epsilon distribution from the Eclipse Epsilon website and follow the installation instructions.
Secondly, once Eclipse is installed, the Xtext framework needs to be installed through the Install New Software... dialog. Select the Eclipse Photon repository at the Work with: drop-down menu and type "xtext" in the search field. Finally, select the checkbox for "Xtext Complete SDK", click Next >, accept the terms, and select Finish to complete the installation (Eclipse restart required).
First, right-click in the Package Explorer view and select Import....
Secondly, select Existing Projects into Workspace.
Then, use the Browse... button located on the right-hand side of the Select root directory: text-field to choose the location of your Xtext projects. Finally, click Finish to import the projects into your workspace.
First, a launch configuration needs to be created to launch an Eclipse Application.
Secondly, make sure that enabled plugins do not cause validation problems by selecting the plug-ins tab and clicking Validate Plug-ins. In case you encounter validation problems, select plugins selected below only in the Launch with: drop-down menu followed by de-selecting plug-ins that cause validation problems.
Next, run the created launch-configuration (a new Eclipse instance will start) and create a new (empty) project by using the Eclipse creation wizard. Finally, create a new (empty) file inside the created project that exactly matches the file-extension that your Xtext DSL specifies. If you are unsure about the file extension that your Xtext DSL defines, take a look at the fileExtensions attribute value in the *.mwe2 file.
To check if the dedicated editor for your Xtext DSL has been loaded properly, press CTRL + Space on your keyboard to open content-assist window. If it has been loaded correctly, it will suggest content that appears in the definition of your DSL.
Once Xtext is installed (a restart of Eclipse is required), the Eclipse creation wizard will show two entries for Xtext: Xtext Project and Xtext Project From Existing Ecore Models.
Before creating a new Xtext project from an existing Ecore, make sure the intended metamodel is registered beforehand. If the intended metamodel is registered successfully, it will appear in the Eclipse View named EPackage Registry.
To open the EPackage Registry, select Window > Show View > Other... followed by selecting Epsilon > EPackage Registry.
Then, refresh the state of the EPackage registry by clicking on the Refresh symbol (i.e. denoted by two yellow arrows) at the top-right of the EPackage Registry window.
If a package with the same Name and Ns URI as depicted in your Ecore metamodel exists in the EPackage Registry, then the intended Ecore metamodel has already been registered.
If not, register the Ecore metamodel by right-clicking on the Ecore metamodel file in the Eclipse Package Explorer view followed by selection of Register EPackages.
Once you have seen the intended metamodel in the EPackage Registry, use the Eclipse wizard to create a Xtext Project From Existing Ecore Models.
Then, use the Add button to add the *.genmodel of your DSL to the wizard for selection.
Select the Entry Rule for your grammar and finalize the wizard by clicking the Finish button. As a result, you will see a set of new projects appearing the in Package Explorer. If the project that contains the *.xtext file, i.e. the grammar of your DSL, appears as erroneous, right-click on your *.ecore file and select Register EPackages; if any change is made to the *.xtext file that allows it to be saved, the errors will disappear (try adding an empty line at the bottom and saving the file).
At this point in time you may edit your grammar and once you are satisfied with its state, you can trigger the MWE2 workflow to auto-generate the components of your DSL by right-clicking on the *.mwe2 file and selecting Run As > MWE2 Workflow and finally launch your editor as described above (see *How to run your Xtext DSL editor).
