How to filter incoming messages#

Installation#

Before you begin, you need to install the library and configure the bot; this process is described in detail here: How to import the library and configure your bot.

How to filter incoming messages and process notification bodies#

Filtering by webhook type occurs automatically by overriding the necessary methods, as described in paragraph: How to receive other notifications, but how to filter by post type?

Since each notification is automatically converted to a java object, you can filter messages by any field yourself. A description of the structure of notification objects can be found at this link: Documentation

For convenience, all java objects and fields are named similarly to the documentation:

You can independently check whether the notification has the type you need and cast the incoming webhook to its class, receiving all its fields.

Link to example: MediaStartScene.java.

public class MediaStartScene extends Scene {
     @Override
     public State processIncomingMessage(MessageWebhook incomingMessage, State currentState) {
         if (incomingMessage instanceof ContactMessageWebhook) {
             answerWithText(incomingMessage, "This is a contact message");

         } else if (incomingMessage instanceof LocationMessageWebhook) {
             answerWithText(incomingMessage, "This is location message");

         } else if (incomingMessage instanceof FileMessageWebhook) {
             answerWithText(incomingMessage, "This is a message with a file");
         }

         return currentState;
     }
}

You can also filter messages by text using the methods of the Scene class. Methods that begin with answerWith... are overloaded, they have the most built-in popular filters based on the text of an incoming message. Examples of using methods of this class will be described below. If you want to set a condition without executing methods class Scene, you can use the methods of the Filter class of this library, which return a boolean value:

Example of using built-in filters#

In this example, the bot will send a message and a file in response to the rates command. Sending a message using the answerWithText() method is triggered only in response to the rates command due to the fact that the third parameter to the answerWithText method the string "rates" is passed. This mechanism is implemented in all methods of the Scene class. If you want to answer everything messages, no filter, just don't specify the third parameter. You can also pass a regex pattern as the third parameter instead of a string.

Uploading a file using the answerWithUploadFile() method is triggered only in response to the rates command due to the fact that the method is located in the if block in the condition of which the method is executed Filter.isMessageTextExpected(incomingMessage, "rates").

Link to example: FiltersStartScene.java.

public class FiltersStartScene extends Scene {
     @Override
     public State processIncomingMessage(MessageWebhook incomingMessage, State currentState) {

         answerWithText(incomingMessage, "You see this because you wrote \"rates\"", "rates"); //filtering by overloaded method

         if (Filter.isMessageTextExpected(incomingMessage, "rates")) { //filtering using the Filter class method
             answerWithUploadFile(incomingMessage, new File("src/main/resources/data/rates.png"));
         }

         return currentState;
     }
}

Full list of scene methods:#

In the overloaded version, message response methods may contain additional expectedMessage parameters and regexPattern, if the text of the incoming message matches the condition, the method will be executed and return the method response according to the documentation; if not, the method will return null.

List of examples#