m2e not picking up generated web resources

I’ve been trying for a few days to get frontend-maven-plugin integrated to our web application build. I quickly got the pom.xml working to process a LESS file into CSS as part of building a WAR.

I added the plugin configured this way:

    <plugin>
        <groupId>com.github.eirslett</groupId>
        <artifactId>frontend-maven-plugin</artifactId>
        <version>1.0</version>

        <installDirectory>target</installDirectory>

        <executions>

            <execution>
                <id>install node and npm</id>
                <goals>
                    <goal>install-node-and-npm</goal>
                </goals>
                <configuration>
                        <nodeVersion>v6.3.0</nodeVersion>
                        <npmVersion>2.15.8</npmVersion>
                </configuration>
            </execution>

            <execution>
                <id>install js packages</id>
                <goals>
                    <goal>npm</goal>
                </goals>
            </execution>

            <execution>
                <id>compile less</id>
                <goals>
                    <goal>gulp</goal>
                </goals>
                <configuration>
                    <srcdir>${basedir}/src/main/less</srcdir>
                    <outputdir>${project.build.directory}/generated-web-resources</outputdir>
                    <arguments>less</arguments>
                </configuration>
            </execution>
        </executions>
    </plugin>

I modified the maven-war-plugin to define additional web resources:

    <webResources combine.children="append">
        <resource>
            <directory>${project.build.directory}/generated-web-resources</directory>
        </resource>
    </webResources>

I’m struggling to get m2e integration to work; when I change the source LESS file, a build is triggered in Eclipse and the resulting CSS file gets written to ./target/generated-web-resources as expected. At this point, I expect the m2e integration to copy the file into the ./target/m2e-wtp/web-resources path, but it takes no action.

If I modify the generated CSS file and save, m2e picks up the change and copies the file to its location in ./target/m2e-wtp/web-resources.

Is there something I need to do in order to have m2e to pick up that there are newly generated files which it should be copying into its resources?

[rtack]

@mriehema how does your comment address the problem. I’ve got the same issue as the others above. m2e-wtp picks up manual changes to the generated resources but does not pick up the files generated and refreshed by the frontend plugin

[stephanpelikan]

You have to declare the directory as a webResource:

			<properties>
				<outputDirectory>${project.build.directory}/generated-web-resources</outputDirectory>
			</properties>
...
				<plugin>
					<groupId>org.apache.maven.plugins</groupId>
					<artifactId>maven-war-plugin</artifactId>
					<version>3.2.0</version>
					<configuration>
						<webResources>
							<resource>
								<directory>${outputDirectory}</directory>
							</resource>
						</webResources>
					</configuration>
				</plugin>
...
					<plugin>
						<groupId>com.github.eirslett</groupId>
						<artifactId>frontend-maven-plugin</artifactId>
						<executions>
...
							<execution>
								<id>webpack build</id>
								<goals>
									<goal>webpack</goal>
								</goals>
								<configuration>
									<arguments>
										-d
										--env.outputDirectory=${outputDirectory}
										--display-error-details
										--config ./webpack.dev.config.js
									</arguments>
									<outputdir>${outputDirectory}</outputdir>
								</configuration>
							</execution>
						</executions>
					</plugin>

Stephan