Blueprints for Helio components

Blueprints for developing new Helio components (use java 11 or above):

1. import the blueprints dependency

	<dependency>
		<groupId>io.github.helio-ecosystem</groupId>
		<artifactId>helio-blueprints</artifactId>
		<version>0.4.21</version>
	</dependency>

2. Add some logging

It is also strongly recommended to add log traces in the component, for this purpose we suggest to add the following dependencies although any log tracker can be used

	<!-- Loggin -->
	<dependency>
		<groupId>org.slf4j</groupId>
		<artifactId>slf4j-api</artifactId>
		<version>${slf4jVersion}</version>
	</dependency>
	<!-- Binding for System.out -->
	<dependency>
		<groupId>org.slf4j</groupId>
		<artifactId>slf4j-simple</artifactId>
		<version>${slf4jVersion}</version>
	</dependency>

3. add plugins for buillding jars that contain all the third-party dependencies

The output jar of the component must include all the third-party dependencies. For this purpose we recommend to add the following excerpt in the pom, more information about how to build a fat jar can be found in this article.

	<build>
		<plugins>
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-assembly-plugin</artifactId>
				<version>3.1.1</version>
				<configuration>
					<descriptorRefs>
						<descriptorRef>jar-with-dependencies</descriptorRef>
					</descriptorRefs>
				</configuration>
				<executions>
					<execution>
						<id>make-assembly</id>
						<phase>package</phase>
						<goals>
							<goal>single</goal>
						</goals>
					</execution>
				</executions>
			</plugin>
		</plugins>
	</build>

4. Putting all together

	<properties>
		<maven.compiler.target>11</maven.compiler.target>
		<maven.compiler.source>11</maven.compiler.source>
		<maven.compiler.release>11</maven.compiler.release>
		<slf4jVersion>1.6.1</slf4jVersion>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
	</properties>

	<dependencies>
		<dependency>
			<groupId>io.github.helio-ecosystem</groupId>
			<artifactId>helio-blueprints</artifactId>
			<version>0.4.21</version>
		</dependency>
		<!-- Loggin -->
		<dependency>
			<groupId>org.slf4j</groupId>
			<artifactId>slf4j-api</artifactId>
			<version>${slf4jVersion}</version>
		</dependency>
		<!-- Binding for System.out -->
		<dependency>
			<groupId>org.slf4j</groupId>
			<artifactId>slf4j-simple</artifactId>
			<version>${slf4jVersion}</version>
		</dependency>

	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-assembly-plugin</artifactId>
				<version>3.1.1</version>
				<configuration>
					<descriptorRefs>
						<descriptorRef>jar-with-dependencies</descriptorRef>
					</descriptorRefs>
				</configuration>
				<executions>
					<execution>
						<id>make-assembly</id>
						<phase>package</phase>
						<goals>
							<goal>single</goal>
						</goals>
					</execution>
				</executions>
			</plugin>
		</plugins>
	</build>

Publishing the new component

Using the component in Helio

Developing a new Mapping Processor

use $ref.get('[VAR]') for enclosing data references in the velocity template, e.g., $ref.get('$.values.[*].measure')

jucanbe/helio-blueprints