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package org.joget.tutorial;
import org.joget.apps.app.model.DefaultHashVariablePlugin;
import org.joget.apps.app.service.AppPluginUtil;
public class BeanShellHashVariable extends DefaultHashVariablePlugin {
private final static String MESSAGE_PATH = "messagemessages/BeanShellHashVariable";
public String getName() {
return "BeanShellHashVariable";
}
public String getVersion() {
return "5.0.0";
}
public String getClassName() {
return getClass().getName();
}
public String getLabel() {
//support i18n
return AppPluginUtil.getMessage("org.joget.tutorial.BeanShellHashVariable.pluginLabel", getClassName(), MESSAGE_PATH);
}
public String getDescription() {
//support i18n
return AppPluginUtil.getMessage("org.joget.tutorial.BeanShellHashVariable.pluginDesc", getClassName(), MESSAGE_PATH);
}
public String getPropertyOptions() {
//Hash variable plugin do not support property options
return "";
}
public String getPrefix() {
return "beanshell";
}
public String processHashVariable(String variableKey) {
throw new UnsupportedOperationException("Not supported yet.");
}
} |
Now, let focus on the main method of our Hash Variable plugin which is processHashVariable.
We will refer to the source code of Environment Variable Hash Variable plugin on how to retrieve the Environment variable. Then, refer to the source code of Bean Shell Form Binder on how to execute a bean shell script.
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public String processHashVariable(String variableKey) {
try {
String environmentVariableKey = variableKey;
//first check and retrieve parameters passed in with URL query parameters syntax wrapped in square bracket []
String queryParams = null;
if (variableKey.contains("[") && variableKey.contains("]")) {
queryParams = variableKey.substring(variableKey.indexOf("[") + 1, variableKey.indexOf("]"));
environmentVariableKey = variableKey.substring(0, variableKey.indexOf("["));
}
//Parse the query parameters to a map
Map<String, String[]> parameters = null;
if (queryParams != null && !queryParams.isEmpty()) {
parameters = StringUtil.getUrlParams(queryParams);
//put all parameters to plugin properties
getProperties().putAll(parameters);
}
//Retrieve the environment variable based on environmentVariableKey
AppDefinition appDef = (AppDefinition) getProperty("appDefinition");
if (appDef != null) {
ApplicationContext appContext = AppUtil.getApplicationContext();
EnvironmentVariableDao environmentVariableDao = (EnvironmentVariableDao) appContext.getBean("environmentVariableDao");
EnvironmentVariable env = environmentVariableDao.loadById(environmentVariableKey, appDef);
if (env != null) {
String script = env.getValue();
//execute the script with all plugin properties
return executeScript(script, getProperties());
} else {
//environment variable not found, return empty value
return "";
}
}
} catch (Exception e) {
//log the exception using LogUtil
LogUtil.error(getClassName(), e, "#beanshell."+variableKey+"# fail to parse.");
}
//return null to by pass the replacing
return null;
}
protected String executeScript(String script, Map properties) throws Exception {
Interpreter interpreter = new Interpreter();
interpreter.setClassLoader(getClass().getClassLoader());
for (Object key : properties.keySet()) {
interpreter.set(key.toString(), properties.get(key));
}
LogUtil.debug(getClass().getName(), "Executing script " + script);
return (String) interpreter.eval(script);
} |
c. Manage the dependency libraries of your plugin
Our plugin class cannot resolve "bsh.Interpreter". So, we will have to add bean shell library to our POM file.
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<!-- Change plugin specific dependencies here -->
<dependency>
<groupId>org.beanshell</groupId>
<artifactId>bsh</artifactId>
<version>2.0b4</version>
</dependency>
<!-- End change plugin specific dependencies here --> |
d. Make your plugin internationalization (i18n) ready
We are using AppPluginUtil.getMessage method to display i18n value for our getLabel and getDescription method. We will have to create a message resource bundle properties file for it. Create directory "resources/messages" under "beanshell_hash_variable/src/main" directory. Then, create a "BeanShellHashVariable.properties" file in it.
In our properties file, we will need to add the key we had used.
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org.joget.tutorial.BeanShellHashVariable.pluginLabel=Bean Shell Hash Variable
org.joget.tutorial.BeanShellHashVariable.pluginDesc=Using environment variable to execute bean shell script. |
e. Register your plugin to Felix Framework
We will have to register our plugin class in Activator class to tell Felix Framework that this is a plugin.
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public void start(BundleContext context) {
registrationList = new ArrayList<ServiceRegistration>();
//Register plugin here
registrationList.add(context.registerService(BeanShellHashVariable.class.getName(), new BeanShellHashVariable(), null));
} |
f. Build it and testing
Let build our plugin. Once the building process is done, we will found a "beanshell_hash_variable-5.0.0.jar" file is created under "beanshell_hash_variable/target" directory.
Then, let upload the plugin jar to Manage Plugins. After upload the jar file, double check the plugin is uploaded and activated correctly.
Now, let test our plugin.
Let assume we have a HTML menu page in userview want to display the following line to logged in user. Normally, we will use "Welcome #currentUser,username#," to display a welcome message.
But, this way has a problem, which is shown "Welcome ," without an username when the user is an anonymous.
Now, change the whole message to our Bean Shell Hash Variable and create an environment variable to put our script.
Change the following
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Welcome #currentUser.username#, |
to the following. We we need to pass the current user's username as one of our parameters and do not forget to escape it as url.
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#beanshell.welcome[username={currentUser.username?url}]?html# |
Then, we can create an environment variable with ID "welcome" and use the following script. Due to we are using getUrlParams method from StringUtil to parse the parameters, all value from parameters are String array.
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//all parameters passed in from Beanshell Hash Variable will converted to String array
if (username != null && username.length == 1 && !username[0].isEmpty()) {
return "Welcome " + username[0] + ",";
} else {
return "";
} |
Let go back to our HTML menu page to see the result.
When user is logged in, it shown the message.
When no user is logged in, it did not show the welcome message.
8. Take a step further, share it or sell it
You can download the source code from beanshell_hash_variable.zip.
To download the ready-to-use plugin jar, please find it in http://marketplace.joget.org/.