Camunda Modeler Template Generator

This project provides a simple Maven plugin to automatically generate template files for the Camunda Modeler based on code annotations. To do this, it uses ClassGraph to scan the classpath for specific annotations. It automatically validates the generated template files against the Camunda schema based on the specified version that should be used.

Features

The main goal of this project is to provide a simple to use Maven plugin that generates template files for the Camunda Modeler without having to write the manually. There are annotations included that can be used in the Java code and which serves as a basis for the generation process. The content of the annotations as well as annotated fields are then scanned with the use of the ClassGraph library that scans the classpath. It is also possible to specify a package to speed up the scanning process. The analyzed annotations are then processed into a Java Object Model which is used to serialize into a JSON format using the Gson library. The generated JSON Strings are validate against the Camunda element-templates-json-schema. The Generator plugin allows to specify a version for the generated template files to use. This version will also be used to validate against. If there is no version provided it will automatically use the latest version available.

Getting started

Installation

To use this Maven plugin in your project, you simply have to add the following code to your pom.xml file.

<plugin>
   <groupId>org.camunda.community.template.generator</groupId>
   <artifactId>template-generator-maven-plugin</artifactId>
   <version>1.0.1</version>
   <executions>
      <execution>
         <goals>
            <goal>template-generator</goal>
         </goals>
      </execution>
   </executions>
   <configuration>
      <schemaVersion>0.10.1</schemaVersion>
      <outputDir>example-output-directory</outputDir>
      <scanPackages>com.mypackage</scanPackages>
      <skipValidation>false</skipValidation>
   </configuration>
</plugin>

The plugin accepts the following arguments to be set in the configuration section:

• schemaVersion: The schema version to use for the generated files and for the validation process.
• outputDir: The directory to save the generated files to.
• scanPackages: The java package to scan for annotations (scans all packages by default).
• skipValidation: Whether the JSON schema validation should be skipped (default is false).

Usage

The plugin provides two basic Java annotations that can be used in the code. These annotations will then be scanned by the plugin to generate the template files. There will be one file for each Java class that contains annotations.

@TemplateProperty This annotation can be used to annotate fields and represents one property in a Template in the Modeler. The following matrix gives an overview about the arguments for this annotation:

Name	Type	Default value	Optional	Description
label	String	""	✔️	The label that will be displayed in the Modeler.
type	String		❌	The property type, e.g. String, Hidden, Dropdown.
value	String	""	✔️	The default value selected in the Modeler.
choices	@Choice[]	{}	✔️	An array containing the choices available in a Dropdown menu.
description	String	""	✔️	The description that is shown at the entry in the Modeler.
documentationRef	String	""	✔️	A URL pointing to documentation.
parameterType	String	"input"	✔️	The parameter type of the property, available options are: "input", "output", "property".
bindingName	String	""	✔️	The binding name that is used together with the parameter type.
scriptFormat	String	""	✔️	The script format to use within the binding.
notEmpty	boolean	false	✔️	Option to say whether an input can be empty or not.
isEditable	boolean	true	✔️	Option to say whether an input can be edited by the user or not.

@Template The Template annotation can be used to annotate methods. This annotation is absolutely necessary because only classes that contain this annotation will be scanned. It represents a Template in the Modeler and contains the corresponding properties which are read from fields of the same class hierarchy annotated with TemplateProperty. Since there might be several activities in one Java class which rely on different properties the Template annotation can optionally contain a list of multiple TemplateProperty annotations that will be included exclusively in the corresponding Template. The following matrix gives an overview about the arguments for this annotation:

Name	Type	Default value	Optional	Description
name	String		❌	The name of the Template shown in the Modeler.
id	String		❌	The id of the Template, e.g. "com.example.Template".
description	String	""	✔️	The description that is shown at the entry in the Modeler.
documentationRef	String	""	✔️	A URL pointing to documentation.
appliesTo	String[]		❌	What this Template should apply to.
function	String	""	✔️	The name of the function that should be called.
functionNameProperty	String	""	✔️	The binding name of the function that should be called.
templateProperties	@TemplateProperty[]	{}	✔️	An optional additional array of TemplateProperty annotations.
entriesVisible	boolean	true	✔️	Option to say if the properties should be visible in the Modeler.

@Choice This annotation should only be used in the choices field of the TemplateProperty annotation. It represents one entry of a dropdown menu.

Name	Type	Default value	Optional	Description
name	String		❌	The name of the dropdown menu entry.
value	String		❌	The value of the dropdown menu entry.

Example 1

 @TemplateProperty(label = "Input",
            description = "Some example input.",
            parameterType = "input",
            type = "String",
            notEmpty = true)

Example 2

 @Template(name = "Example",
            id = "com.example.Example",
            description = "Example Template",
            appliesTo = { "bpmn:Task" },
            templateProperties = {
                    @TemplateProperty(label = "Example Additional Property",
                            description = "Example of an additional property",
                            parameterType = "input",
                            type = "String",
                            value = "example",
                            bindingName = "exampleAdditionalProperty") })

License

Apache License, Version 2.0