Plugin repeater maven plugin

Summary
Simple Example
Default Variable Groups
Conditional Inclusion

Summary

The plugin repeater maven plugin allows you to follow the DRY principal when writing your POM files.

If you've ever had to write a very similar plugin execution dozens of times then this is the plugin for you.

The plugin repeater plugin lets you repeat a plugin execution with different variables substituted.

All the examples in this README assume that we have a fictional plugin, adder-maven-plugin, that adds numbers. Anywhere you see  means that we've left out the plugin GAV as well as any tags that aren't necessary. This may mean it is in the contentPlugin section of a repeater plugin configuration or a plugin inside a pom's plugins section. The context should provide that information for you.

Simple Example

Say we wanted to add 5 sets of two numbers. Normally you'd have to write something like this:

<plugin>
    <groupId>fake.plugin.group</groupId>
    <artifactId>adder-maven-plugin</artifactId>
    <version>0.0.0</version>
    <executions>
        <execution>
            <id>first-number-add</id>
            <goals>
                <goal>add</goal>
            </goals>
            <configuration>
                <numberOne>1</numberOne>
                <numberTwo>2</numberTwo>
            </configuration>
        </execution>
        <execution>
            <id>second-number-add</id>
            <goals>
                <goal>add</goal>
            </goals>
            <configuration>
                <numberOne>3</numberOne>
                <numberTwo>4</numberTwo>
            </configuration>
        </execution>
        <execution>
            <id>third-number-add</id>
            <goals>
                <goal>add</goal>
            </goals>
            <configuration>
                <numberOne>5</numberOne>
                <numberTwo>6</numberTwo>
            </configuration>
        </execution>
        <execution>
            <id>four-number-add</id>
            <goals>
                <goal>add</goal>
            </goals>
            <configuration>
                <numberOne>7</numberOne>
                <numberTwo>8</numberTwo>
            </configuration>
        </execution>
        <execution>
            <id>fifth-number-add</id>
            <goals>
                <goal>add</goal>
            </goals>
            <configuration>
                <numberOne>9</numberOne>
                <numberTwo>10</numberTwo>
            </configuration>
        </execution>
    </executions>
</plugin>

With the plugin repeater maven plugin you can just write:

<plugin>
    <groupId>com.nlocketz.plugins</groupId>
    <artifactId>plugin-repeater-maven-plugin</artifactId>
    <!-- Check maven central for latest version -->
    <version>LATEST</version>
    <executions>
        <execution>
            <id>run-addings</id>
            <goals>
                <goal>repeat</goal>
            </goals>
            <configuration>
                <repetitions>
                    <!-- Each repetition corresponds to a single run of contentPlugin -->
                    <!-- The values mapped in the repetition are subbed in @ surrounded tags -->
                    <repetition>
                        <nOne>1</nOne>
                        <nTwo>2</nTwo>
                    </repetition>
                    <repetition>
                        <nOne>3</nOne>
                        <nTwo>4</nTwo>
                    </repetition>
                    <repetition>
                        <nOne>5</nOne>
                        <nTwo>6</nTwo>
                    </repetition>
                    <repetition>
                        <nOne>7</nOne>
                        <nTwo>8</nTwo>
                    </repetition>
                    <repetition>
                        <nOne>9</nOne>
                        <nTwo>10</nTwo>
                    </repetition>
                </repetitions>
                <contentPlugin>
                    <groupId>fake.plugin.group</groupId>
                    <artifactId>adder-maven-plugin</artifactId>
                    <version>0.0.0</version>
                    <executions>
                        <execution>
                            <id>repeat-add</id>
                            <goals>
                                <!-- Every goal will be run. -->
                                <!-- the adder-maven-plugin only has one goal -->
                                <goal>add</goal>
                            </goals>
                            <!-- NOTE: Due to a limitation of the maven plugin API -->
                            <!-- this doesn't support the phase tag. All the executions -->
                            <!-- are run in the same phase as your plugin-repeator-maven-plugin -->
                            <configuration>
                                <!-- These @ surrounded variables are replaced with their -->
                                <!-- corresponding values during each repetition. -->
                                <numberOne>@nOne@</numberOne>
                                <numberTwo>@nTwo@</numberTwo>
                            </configuration>
                        </execution>
                    </executions>
                </contentPlugin>
            </configuration>
        </execution>
    </executions>
</plugin>

Default Variable Groups

If you have some repetitions that all use a certain variable with a certain value, except 1, you'd have to repeat that variable in the repetitions (violating the DRY principal). Fear not! We have thought of this, and added a feature called repetitionGroups that allow you to set defaults for certain repetitions, and override it for others.

Here is an example:

<!-- Boilerplate omitted -->
<execution>
    <id>run-addings</id>
    <goals>
        <goal>repeat</goal>
    </goals>
    <configuration>
        <repetitions>
            <repetitionGroup>
                <!-- Here we set a default for 'nOne'. -->
                <!-- If any repetitions nested inside this repetitionGroup -->
                <!-- *don't* declare 'nOne', it will be supplied by the most recent default. -->
                <!-- In this case that is the top level repetition group, and 2. -->
                <nOne>2</nOne>
                <repetition>
                    <nTwo>2</nTwo>
                </repetition>
                <repetition>
                    <nTwo>3</nTwo>
                </repetition>
                <repetition>
                    <nTwo>4</nTwo>
                    <nOne>4</nOne>
                </repetition>
            </repetitionGroup>
        </repetitions>
        ...
        <!-- Same as before ... -->
        ...
    </configuration>
</execution>

which is equivalent to:

<!-- Boilerplate omitted -->
<executions>
    <execution>
        <!-- NOTE: even though these have the same execution ID -->
        <!-- they will all be run inside the plugin-repeater-maven-plugin -->
        <id>repeat-add</id>
        <goals>
            <goal>add</goal>
        </goals>
        <configuration>
            <numberOne>2</numberOne>
            <numberTwo>2</numberTwo>
        </configuration>
    </execution>
    <execution>
        <id>repeat-add</id>
        <goals>
            <goal>add</goal>
        </goals>
        <configuration>
            <numberOne>2</numberOne>
            <numberTwo>3</numberTwo>
        </configuration>
    </execution>
    <execution>
        <id>repeat-add</id>
        <goals>
            <goal>add</goal>
        </goals>
        <configuration>
            <numberOne>4</numberOne>
            <numberTwo>4</numberTwo>
        </configuration>
    </execution>
</executions>

You can even nest these as deeply as you want!

<!-- Boilerplate omitted -->
<execution>
    <id>run-addings</id>
    <goals>
        <goal>repeat</goal>
    </goals>
    <configuration>
        <repetitions>
            <repetitionGroup>
                <nOne>2</nOne>
                <repetitionGroup>
                    <nTwo>2</nTwo>
                    <repetition>
                        <nOne>10</nOne>
                    </repetition>
                </repetitionGroup>
                <repetition>
                    <nTwo>-1</nTwo>
                </repetition>
            </repetitionGroup>
        </repetitions>
        ...
        <!-- Same as before ... -->
        ...
    </configuration>
</execution>

is equivalent to:

<!-- Boilerplate omitted -->
<executions>
    <execution>
        <id>repeat-add</id>
        <goals>
            <goal>add</goal>
        </goals>
        <configuration>
            <numberOne>10</numberOne>
            <numberTwo>2</numberTwo>
        </configuration>
    </execution>
    <execution>
        <id>repeat-add</id>
        <goals>
            <goal>add</goal>
        </goals>
        <configuration>
            <numberOne>2</numberOne>
            <numberTwo>-1</numberTwo>
        </configuration>
    </execution>
<executions>

Small gotcha

Due to limitations on maven's XML, you cannot currently do something like this:

<!-- Boilerplate omitted -->
<execution>
    <id>run-addings</id>
    <goals>
        <goal>repeat</goal>
    </goals>
    <configuration>
        <repetitions>
            <repetitionGroup>
                <nOne>2</nOne>
                <repetitionGroup>
                    <nTwo>2</nTwo>
                    <!-- neither of the following tags will be recognized! -->
                    <!-- Even though they are unambiguous in terms of their intention -->
                    <repetition/>
                    <repetition>
                    </repetition>
                </repetitionGroup>
            </repetitionGroup>
        </repetitions>
        ...
        <!-- Same as before ... -->
        ...
    </configuration>
</execution>

Conditional XML Inclusion

The plugin-repeater-maven-plugin also supports conditional inclusion of XML for content plugins. Currently you can only make the decision based on whether a filter variable is defined for the current repetition or not.

In order to conditionally include a tag, myTag inside the configuration of your content plugin you can do the following:

<configuration>
    <myTag if="myVar">@myVar@</myTag>
</configuration>

This includes <myTag>myVarValue</myTag> if myVar has a definition for the current repetition. An important note for this is that a failed condition excludes everything within the failing tag. Any nested XML tags will also be excluded as well as any attributes or string contents.

The plugin-repeater-maven-plugin also supports the unless attribute.

Here is a toy usage:

<!-- Boilerplate omitted -->
<execution>
    <id>run-addings</id>
    <goals>
        <goal>repeat</goal>
    </goals>
    <configuration>
        <repetitions>
            <repetition>
                <nOne>1</nOne>
                <nTwo>2</nTwo>
            </repetition>
            <repetition>
                <nTwo>5</nTwo>
            </repetition>
        </repetitions>
        <contentPlugin>
            <groupId>fake.plugin.group</groupId>
            <artifactId>adder-maven-plugin</artifactId>
            <version>0.0.0</version>
            <executions>
                <execution>
                    <id>repeat-add</id>
                    <goals>
                        <goal>add</goal>
                    </goals>
                    <configuration>
                        <numberOne if="nOne">@nOne@</numberOne>
                        <numberOne unless="nOne">0</numberOne>
                        <numberTwo>@nTwo@</numberTwo>
                    </configuration>
                </execution>
            </executions>
        </contentPlugin>
    </execution>
</executions>

which equivalent to:

<!-- Boilerplate omitted -->
<executions>
    <execution>
        <id>repeat-add</id>
        <goals>
            <goal>add</goal>
        </goals>
        <configuration>
            <numberOne>1</numberOne>
            <numberTwo>2</numberTwo>
        </configuration>
    </execution>
    <execution>
        <id>repeat-add</id>
        <goals>
            <goal>add</goal>
        </goals>
        <configuration>
            <numberOne>0</numberOne>
            <numberTwo>5</numberTwo>
        </configuration>
    </execution>
<executions>

com.nlocketz.plugins:plugin-repeater-maven-plugin
Release 0.0.13

Release 0.0.13

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0.0.4

0.0.3

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0.0.1

Documentation

Plugin repeater maven plugin

Table of contents

Summary

Simple Example

Default Variable Groups

Small gotcha

Conditional XML Inclusion

Stats

Development practices

Releases

Contributors

com.nlocketz.plugins:plugin-repeater-maven-plugin Release 0.0.13

Release 0.0.13 Toggle Dropdown 0.0.13 0.0.7 0.0.6 0.0.5 0.0.4 0.0.3 0.0.2 0.0.1

Documentation

Plugin repeater maven plugin

Table of contents

Summary

Simple Example

Default Variable Groups

Small gotcha

Conditional XML Inclusion

Stats

Development practices

Releases

Contributors

com.nlocketz.plugins:plugin-repeater-maven-plugin
Release 0.0.13

Release 0.0.13

0.0.13

0.0.7

0.0.6

0.0.5

0.0.4

0.0.3

0.0.2

0.0.1