In this tutorial, we will follow the guideline for developing a plugin to develop our Slack Webhook Tool plugin. Please also refer to the very first tutorial How to develop a Bean Shell Hash Variable for more details steps.
1. What is the problem?
We want to send message to Slack when something is completed in Joget Workflow.
2. How to solve the problem?
We will develop a Process Tool & Post Form Submission Processing Plugin to send message to Slack.
3. What is the input needed for your plugin?
To develop a Slack Webhook Tool plugin, we will consider providing the parameters available in Slack Incoming Webhook as our plugin input.
4. What is the output and expected outcome of your plugin?
When the tool is execute, a message will send to Slack based on the configuration.
5. Are there any resources/API that can be reused?
We can use slack-webhook library to integrate with Slack.
6. Prepare your development environment
We need to always have our Joget Workflow Source Code ready and builded by following this guideline.
The following tutorial is prepared with a Macbook Pro and the Joget Source Code is version 5.0.1. Please refer to the Guideline for developing a plugin article for other platform commands.
Let's say our folder directory is as follows.
The "plugins" directory is the folder we will create and store all our plugins and the "jw-community" directory is where the Joget Workflow Source code is stored.
Run the following command to create a maven project in "plugins" directory.
Then, the shell script will ask us to key in a version number for the plugin and ask us for a confirmation before it generates the maven project.
We should get a "BUILD SUCCESS" message shown in our terminal and a "slack_webhook" folder created in the "plugins" folder.
Open the maven project with your favourite IDE. I will be using NetBeans.
7. Just code it!
a. Extending the abstract class of a plugin type
Create a "SlackWebhookTool" class under "org.joget" package. Then, extend the class with org.joget.plugin.base.DefaultApplicationPlugin abstract class. Please refer to Process Tool & Post Form Submission Processing Plugin. We will need to implement org.joget.plugin.base.PluginWebSupport interface class as well to provide a send test message button in plugin properties page. Please refer to Web Service Plugin.
b. Implement all the abstract methods
As usual, we have to implement all the abstract methods. We will using AppPluginUtil.getMessage method to support i18n and using constant variable MESSAGE_PATH for message resource bundle directory.
Now, we have to create a UI for admin user to provide inputs for our plugin. In getPropertyOptions method, we already specify our Plugin Properties Options definition file is located at "/properties/slackWebhookTool.json". Let us create a directory "resources/properties" under "slack_webhook/src/main" directory. After creating the directory, create a file named "slackWebhookTool.json" in the "properties" folder.
In the properties definition options file, we will need to provide options as below. Please note that we can use "@@message.key@@" syntax to support i18n in our properties options.
After completing the properties option to collect input, we can work on the main methods of the plugin which is execute method.
In our plugin properties, we have a button to send test message. Let implement the webService method to provide an API to send test message.
c. Manage the dependency libraries of your plugin
We need to include "jsp-api" and "slack-webhook" libraries in our POM file.
d. Make your plugin internationalization (i18n) ready
We are using i18n message key in getLabel and getDescription method. We will use i18n message key in our properties options definition as well. Then, we will need to create a message resource bundle properties file for our plugin.Create a directory, "resources/message", under "slack_webhook/src/main" directory. Then, create a "SlackWebhookTool.properties" file in the folder. In the properties file, add all the message keys and its label as below.
e. Register your plugin to the Felix Framework
Next, we will have to register our plugin class in the Activator class (Auto generated in the same class package) to tell the Felix Framework that this is a plugin.
f. Build it and test
Let's build our plugin. Once the building process is done, we will find a "slack_webhook-5.0.0.jar" file created under "slack_webhook/target" directory.
Then, let's upload the plugin jar to Manage Plugins. After uploading the jar file, double check that the plugin is uploaded and activated correctly.
Check the Slack Webhook Tool is available in process tool mapping.
Now, let us configure the Incoming Webhooks in Slack platform.
Go to your_team.slack.com/services/new.
Search for Incoming WebHook and click in
Choose Channel to Post and press
Add Incoming WebHooks Integration
Into Setup Instructions, you've a WebHook URL. This is the argument will use for the "Webhook URL" later. Then, copy it.
Configure the Slack Webhook Tool.
The message is received in Slack.
8. Take a step further, share it or sell it
You can download the source code from slack_webhook_src.zip.
To download the ready-to-use plugin jar, please find it in http://marketplace.joget.org/. (Coming Soon)