Blackboard Building Block Logging Utilities

A Java library containing utility classes to assist with logging in Blackboard. At the moment it only contains two classes, both are Logback PropertyDefiners used to get your Building Block's logs or config directory.

Building

The build tool used is called Gradle. It will do all the work to build the library, including downloading dependencies, compiling java classes and zipping up the JAR. This is all done with a single command - no installation necessary. From the root of the project execute the following command:

Windows: gradlew build

GNU/Linux & Mac OSX: ./gradlew build

The built file will be output to the build/libs/b2-logging-utils-[version].jar location.

Cleaning

If you want to clean the build artifacts execute this command:

Windows: gradlew clean

GNU/Linux & Mac OSX: ./gradlew clean

Using Logback to write to your Building Block's log directory

(This assumes you are already using Logback in your project.)

• Add the JAR as a dependency in your project. The steps to do this will vary depending upon your build tool. In gradle, this can be done by adding the following line to the dependencies:

compile files('path/to/jar/b2-logging-utils-[version].jar)

• Add the following XML to your logback configuration file:

<define name="pluginLogDir" class="com.alltheducks.logging.logback.BbPluginLogDirPropertyDefiner">
    <vendorId>me</vendorId>
    <handle>myplugin</handle>
</define>

• Add the following XML to your B2 permissions in the bb-manifest.xml (unfortunately, at this time, write permissions are required to the plugins directory simply so that Logback can create the subdirectory for your plugin.):

<permission type="java.io.FilePermission" name="BB_HOME/logs/plugins/-" actions="write" />

• Now you can use the ${pluginLogDir} property to configure your appenders how ever you like. Blackboard has a prescribed format for logging in their SaaS environment. It probably also a good idea to have a new log file each day. Here is an example which brings this all together:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>

    <define name="pluginLogDir" class="com.alltheducks.logging.logback.BbPluginLogDirPropertyDefiner">
        <vendorId>me</vendorId>
        <handle>myplugin</handle>
    </define>

    <appender name="default" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>${pluginLogDir}/me-myplugin.log</file>
        <append>true</append>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>${pluginLogDir}/me-myplugin.%d{yyyy-MM-dd}.log</fileNamePattern>
        </rollingPolicy>
        <encoder>
            <!-- This pattern ensures logging will work in Learn SaaS -->
            <pattern>%date{yyyy-MM-dd HH:mm:ss} | %-5level | %-45(%L:%logger{40}) | %m%n%ex{10}</pattern>
        </encoder>
    </appender>
    <logger name="com.alltheducks.myplugin" level="DEBUG"/>
    <root level="WARN">
        <appender-ref ref="default"/>
    </root>
</configuration>

Writing to your Building Block's config directory:

Occasionally, you may wish to write some logs to your Building Block's config directory. This is rare and should be thought through beforehand, but if you want to achieve this use the com.alltheducks.logging.logback.BbPluginConfigDirPropertyDefiner instead.