Create Apex Handlers for Slack Apps

Use these Apex classes to create handlers for Slack actions, commands, shortcuts, and events.

ActionDispatcher Class

The Slack.ActionDispatcher class enables you to invoke an action handler such as in response to a form submission.

Usage

Extend the ActionDispatcher class and override the invoke() method.

1public class MyActionDispatcher extends Slack.ActionDispatcher {
2
3    public override Slack.ActionHandler invoke(Map<String, Object> parameters, Slack.RequestContext context) {
4        return Slack.ActionHandler.modal(new Handler(context));
5    }
6}

Examples

This example uses ActionDispatcher to handle a form submission.

1public class ExampleFormSubmissionDispatcher extends Slack.ActionDispatcher {
2
3    public override Slack.ActionHandler invoke(Map<String, Object> parameters, Slack.RequestContext context) {
4        return Slack.ActionHandler.modal(new Handler(context));
5    }
6
7    public class Handler implements Slack.ModalHandler {
8        Slack.RequestContext context;
9        public Handler (Slack.RequestContext context){
10            this.context = context;
11        }
12        public Slack.ModalView call () {
13            Map <String, Object> formData = context.getFormData();
14            Slack.ViewReference viewReference = Slack.View.message_modal.get();
15            viewReference.setParameter('title', 'Form Field Value');
16            viewReference.setParameter('message', (String) formData.get('FormFieldName'));
17            Slack.ModalView modalView = new Slack.ModalView.builder()
18                .viewReference(viewReference)
19                .build();
20            return modalView;
21        }
22    }
23}

This example uses ActionDispatcher to display a view.

1public class createOpportunity extends Slack.ActionDispatcher {
2    public override Slack.ActionHandler invoke(Map<String, Object> parameters, Slack.RequestContext context) {
3        return Slack.ActionHandler.modal(new Handler(parameters, context));
4    }
5    public class Handler implements Slack.ModalHandler {
6        Map<String, Object> parameters;
7        Slack.RequestContext context;
8        public Handler (Map<String, Object> parameters, Slack.RequestContext context){
9            this.parameters = parameters;
10            this.context = context;
11        }
12        public Slack.ModalView call () {
13            Slack.ViewReference viewReference = Slack.View.create_opportunity.get();
14            viewReference.setParameter('title', 'Record Created');
15            viewReference.setParameter('message', 'Your opportunity was created');
16            Slack.ModalView modalView = new Slack.ModalView.builder()
17                .viewReference(viewReference)
18                .build();
19            return modalView;
20        }
21    }

You can close the modal and optionally clear the view stack by using clearModal(). To close the modal without clearing the view stack, use ack(handler) instead.

1public class ExampleViewSubmissionDispatcher extends Slack.ActionDispatcher {
2
3    public override Slack.ActionHandler invoke(Map<String, Object> parameters, Slack.RequestContext context) {
4        // Tell the framework how to respond first
5
6        // Close the modal and clear the whole stack
7        return Slack.ActionHandler.clearModal(new Handler(parameters, context));
8    }
9
10    public class Handler implements Slack.ModalHandler {
11
12        Map<String, Object> parameters;
13        Slack.RequestContext context;
14
15        public Handler (Map<String, Object> parameters, Slack.RequestContext context) {
16            this.parameters = parameters;
17            this.context = context;
18        }
19
20        public void run () {
21            // Process the request (e.g. context.getFormData())
22        }
23    }
24}

For an example of invoking an action handler on the App Home page, such as with SlashCommandDispatcher, see ChatPostMessageRequest.

Tip

ActionDispatcher Methods

These methods are for ActionDispatcher.

allowUnauthenticatedUsers()

Signature

1public Boolean allowUnauthenticatedUsers()

Return Value

Type: Boolean

invoke(parameters, context)

Invokes the action handler.

Signature

1public Slack.ActionHandler invoke(
2  Map<String, Object> parameters,
3  Slack.RequestContext context
4);

Parameters

parameters

Type: Map<String, Object>

The action parameters or other parameters of EventParameters, ShortcutParameters, or SlashCommandParameters type.

context

Type: Slack.RequestContext

Describes the context in which a Slack action is invoked.

Return Value

Type: Slack.ActionHandler

Usage

To access the Slack context, use the invoke() method. This method is passed in by an instance of RequestContext. It exposes information about the source of the action in Slack, performs custom logic, and obtains the correct Slack client to respond to Slack based on the request.

Each action type receives different information in its RequestContext.

ActionHandler Class

The Slack.ActionHandler class provides methods that control how Slack actions are handled. The handler processes a single request.

Usage

With the ActionHandler methods, you can work with modals. By responding to Slack actions with a modal you can display dynamic and interactive information. Before opening a modal, compose a view object to define the layout of the initial view.

A modal can hold up to three views simultaneously in a view stack. Only one view is visible each time. But the view stack can retain previous views and return to them with their prior state in place. An app can push new views onto a modal’s view stack or update an existing view within that stack, including the currently visible view.

To use this Apex class, specify the Slack namespace when creating an instance of this class. Override the invoke() method returning a Slack.ActionHandler.

Examples

This example pushes a modal onto the modal view stack.

1public class createRecord extends Slack.ActionDispatcher {
2
3    public override Slack.ActionHandler invoke(Map<String, Object> parameters, Slack.RequestContext context) {
4        // the slack action handler is returned immediately
5        return Slack.ActionHandler.pushModal(new Handler(parameters, context));
6    }
7
8    public class Handler implements Slack.ModalHandler {
9
10        Map<String, Object> parameters;
11        Slack.RequestContext context;
12
13        public Handler (Map<String, Object> parameters, Slack.RequestContext context) {
14            this.parameters = parameters;
15            this.context = context;
16        }
17
18        public Slack.ModalView call () {
19            Slack.ViewReference viewReference = Slack.View.message_modal.get();
20            viewReference.setParameter('title', 'Title');
21            viewReference.setParameter('message', 'Message');
22            Slack.ModalView modalView = new Slack.ModalView.builder()
23                .viewReference(viewReference)
24                .build();
25            return modalView;
26        }
27
28    }
29}

The message_modal.view file looks like this.

1description: "This is a simple component that displays a message in a modal"
2schema:
3  properties:
4    title:
5      type: string
6      required: true
7    message:
8      type: string
9      required: true
10components:
11  - definition: modal
12    properties:
13      title: "{!view.properties.title}"
14    components:
15      - definition: section
16        properties:
17          text: "{!view.properties.message}"

ActionHandler Methods

The following are methods for ActionHandler.

ack(handler)

Acknowledge the payload back to Slack to avoid the 3-second timeout. After running this method, you can perform Slack Client API calls such as to post messages and publish to app home. For example, you can listen to the app_home_opened event and publish a new view to the user’s Home tab. ack() takes care of responding back to Slack immediately to avoid the 3-second timeout.

We don’t recommend using ack() for displaying modals subject to the trigger_id timeouts because doing so can cause your code to fail intermittently, depending on the environment.

To create, update, or push a modal view, use pushModal(), modal(), or updateModal() instead. These methods ack back to Slack within 3 seconds so that the trigger_id from Slack doesn’t expire using a staging modal. Using these methods, your Handler must return a ModalView for Slack to display. See Create an Apex Handler.

Signature

1public static Slack.ActionHandler ack(Slack.RunnableHandler handler)

Parameters

handler

Type: Slack.RunnableHandler

The handler that clears the modal from the view stack.

Return Value

Type: Slack.ActionHandler

clearModal(handler)

Clears the full stack of modals. By default, Slack pops one modal off the top of the stack.

Signature

1public static Slack.ActionHandler clearModal(RunnableHandler handler)

Parameters

handler

Type: RunnableHandler

The handler that clears the modal from the view stack.

Return Value

Type: Slack.ActionHandler

modal(handler)

Displays a Loading modal with automatic staging to satisfy the 3-second timeout rule.

Signature

1public static Slack.ActionHandler modal(Slack.ModalHandler handler)

Parameters

handler

Type: Slack.ModalHandler

The handler for the modal.

Return Value

Type: Slack.ActionHandler

Window(handler, stagedModalTitle)

Displays a Loading modal with a title. The modal has automatic staging to satisfy the 3-second timeout rule.

Signature

1public static Slack.ActionHandler modal(
2  Slack.ModalHandler handler,
3  String stagedModalTitle
4)

Parameters

handler

Type: Slack.ModalHandler

The handler for the modal.

stagedModalTitle

Type: String

The title to display on the modal in Slack.

Return Value

Type: Slack.ActionHandler

pushModal(handler)

Pushes another modal to the view stack with automatic staging to satisfy the 3-second timeout.

Signature

1public static Slack.ActionHandler pushModal(Slack.ModalHandler handler)

Parameters

handler

Type: Slack.ModalHandler

The handler that pushes the modal to the view stack.

Return Value

Type: Slack.ActionHandler

pushModal(handler, stagedModalTitle)

Push another modal to the view stack with a different title.

Signature

1public static Slack.ActionHandler pushModal(
2  Slack.ModalHandler handler,
3  String stagedModalTitle
4)

Parameters

handler

Type: Slack.ModalHandler

The handler that pushes the modal to the view stack.

stagedModalTitle

Type: String

The title to display on the modal in Slack.

Return Value

Type: Slack.ActionHandler

updateModal(handler)

Updates a modal. This update can happen if the view is visible within the modals’s view stack.

Signature

1public static Slack.ActionHandler updateModal(Slack.ModalHandler handler)

Parameters

handler

Type: Slack.ModalHandler

The handler that updates the modals.

Return Value

Type: Slack.ActionHandler

updateModal(handler, stagedModalTitle)

Updates a modals with a different title. This update can happen whether the view is visible within the modal’s view stack.

Signature

1public static Slack.ActionHandler updateModal(
2  Slack.ModalHandler handler,
3  String stagedModalTitle
4)

Parameters

handler

Type: Slack.ModalHandler

The handler that updates the modal.

stagedModalTitle

Type: String

The title to display on the modal in Slack.

Return Value

Type: Slack.ActionHandler

ActionPayload Class

Contains the name and values associated with the block element that triggered the action.

Usage

Use the ActionPayload class to register an event, such as an onchange or onclick event, and associate the event to an action. You can retrieve the value from the payload to display it in the view or use the value to perform a query and so on.

Specify your action payload in the run() callback method.

1// Set the context using Slack.RequestContext
2Slack.ActionPayload actionPayload = context.getActionPayload();
3    if (actionPayload != null) {
4        String name = actionPayload.getName();
5        // do something with the payload
6    }

See ChatPostMessageRequest for an example that retrieves the value of the payload and publish it to a view.

ActionPayload Methods

The following are methods for ActionPayload.

getName()

Returns the name of the block element.

Signature

1public String getName()

Return Value

Type: String

getType()

Returns the type of the block element.

Signature

1public String getType()

Return Value

Type: String

getValue()

Returns the value of the block element.

Signature

1public Object getValue()

Return Value

Type: Object

ActionPayload.Builder Class

Contains methods to build an instance of the Slack.ActionPayload class.

A Builder object is obtained by invoking one of the ActionPayload.Builder methods defined by the ActionPayload class.

ActionPayload.Builder Methods

The following are methods for ActionPayload.Builder.

build()

Returns an instance of the Slack.ActionPayload object.

Signature

1public Slack.ActionPayload build()

Return Value

Type: Slack.ActionPayload

name(name)

Signature

1public Slack.ActionPayload.Builder name(String name)

Parameters

type

Type: String

Return Value

Type: Slack.ActionPayload.Builder

type(type)

Signature

1public Slack.ActionPayload.Builder type(String type)

Parameters

type

Type: String

Return Value

Type: Slack.ActionPayload.Builder

value(value)

Signature

1public Slack.ActionPayload.Builder value(Object value)

Parameters

value

Type: Object

Return Value

Type: Slack.ActionPayload.Builder

Beta Feature

This feature is not generally available. It is not part of your purchased Services. This feature is subject to change, may be discontinued with no notice at any time in SFDC’s sole discretion, and SFDC may never make this feature generally available. Make your purchase decisions only on the basis of generally available products and features. This feature is made available on an AS IS basis and use of this feature is at your sole risk.