The Vapid Public key can be retrieved by loading a prime256v1 EC Private Key PEM file using PRIM_CAP.PrivateKey. After loading, you can retrieve the VapidPublicKey, which returns an encoded string that can be passed to the web application.
Mthroutine Name(GetVapidKey)
Define_Map For(*RESULT) Class(#Prim_dc.UnicodeString) Name(#result)
#xPushManagerPrivateKeyPath := *TEMP_DIR + 'PrivateKeys' + *PATHDELIM + 'ECPrivatekey.pem'
If (#PrivateKey.LoadPemFile( #xPushManagerPrivateKeyPath ))
#result := #PrivateKey.VapidPublicKey
Endif
Endroutine
The Push Manager is defined inside of a web component and gives access to properties, methods, and events for maintaining a user’s push notifications.
Define_Com Class(#PRIM_WEB.PushManager) Name(#PushManager)
The Query asks the service worker to find the permission status of the push notifications for the user, the feature status of push notifications, the subscription reference to the user's subscription, and the notification history, a list of messages previously received by the user in the browser. This process will trigger the changes event which will be used to gather the appropriate properties.
Mthroutine Name(CheckSubscription)
#PushManager.Query
Endroutine
Subscribes a user to receive push notifications. Once the subscription is completed in the service worker, the push manager changed event will be triggered.
Evtroutine Handling(#ButtonSubscribe.Click)
#Subscribing := True
#PushManager.Subscribe( #xPushManagerVapidPublicKey )
Endroutine
Stops the user from receiving push notifications. Once the unsubscription is completed in the service worker, the push manager changed event will be triggered.
Evtroutine Handling(#ButtonUnsubscribe.Click)
#UnSubscribing := True
#PushManager.Unsubscribe
Endroutine
The change event is triggered to show a change in the push notification status or that all subscription details have been received. This means that the derived properties from the service worker will be up to date.
Evtroutine Handling(#PushManager.Changed)
#xPushManagerFeatureStatus := #PushManager.FeatureStatus
#xPushManagerPermissionsStatus := #PushManager.PermissionStatus
#xPushSubscriptionObject #xPushSubscriptionEndpoint := ""
If ((#xPushManagerFeatureStatus = 'Subscribed') *And (#xPushManagerPermissionsStatus = 'Granted'))
#xPushSubscriptionObject := #PushManager.Subscription.SubscriptionObject
#xPushSubscriptionEndpoint := #PushManager.Subscription.Endpoint
#ButtonSubscribe.Enabled := False
#ButtonUnsubscribe.Enabled := true
If (#Subscribing)
#com_self.SendSusbscription
#Subscribing := False
Endif
Else
If (#UnSubscribing)
#com_self.UnsubscribeUser
#UnSubscribing := False
Endif
#ButtonSubscribe.Enabled := (#PushManager.FeatureStatus <> Unsupported) *And (#PushManager.FeatureStatus <> Failed) *And (#PushManager.PermissionStatus <> Denied)
#ButtonUnsubscribe.Enabled := False
Endif
Endroutine
Returns an enumeration based on the permission to receive push notifications for that web app. Values and meanings are:
Unknown – Details of notification permissions have not or could not be retrieved.
Granted – The user has granted permission to receive push notifications.
Denied - The user has denied the request to receive push notifications from this application.
Prompt - The user needs to grant permission.
Failed - The retrieval of the notifications status has failed.
#PushNotificationFeatureStatus := #PushManager.FeatureStatus
#PushNotificationPermissionsStatus := #PushManager.PermissionStatus
The feature status returns an enumeration based on the web applications service worker and its status for receiving push notifications, the values, and their meanings are:
Unsupported - The browser the user is using does not support push notifications and/or the web application is not a PWA.
NotSubscribed – The application supports notifications but the user has yet to subscribe.
Subscribed - The user is subscribed to receive push notifications.
Pending - The service worker is still processing a subscription.
Failed - An error occurred in creating push notification subscription.
#PushNotificationFeatureStatus := #PushManager.FeatureStatus
#PushNotificationPermissionsStatus := #PushManager.PermissionStatus
Returns a reference to a user’s subscription. See the PushManager Subscription for more details.
Returns an iterator containing previously received push notifications and values for their content. These values are badge, body, icon, image, tag, timestamp, title, and URL.
The push manager subscription holds the details of a user subscription in two properties: SubscriptionObject and Endpoint.
The SubscriptionObject is an encoded string that returns a user's subscription detail. The subscription object should not be altered when setting it for sending the push notification.
The SubscriptionEndpoint is a unique URL that points to a user agent that then forwards the notification to the service worker.
Manages the building, encrypting, and sending of push notifications.
Define_Com Class(#Prim_srvm.HttpPushMessage) Name(#Push)
Specifies the email address of the application administrator for use in the JWT Claim. Group emails are preferred over individual email accounts.
Specifies how long the JWT Claim will be valid in seconds. Values must be between 1 and 86,400.
Returns the HTTP Response from the PushSend method.
Specifies the image to be used as the badge of a push notification, the badge is displayed when there is not enough space to show the content of a notification, such as in smartphone notification centres.
Specifies the content of the message body to be displayed.
Specifies the direction of the enumeration values and meanings are: Auto – Text direction be determined from the iso language used. RightToLeft – Text will be displayed from right to left LeftToRight – Text will be displayed from left to right.
Specifies the image to be used as the icon of a push notification.
PushMessageImageUrl specifies the image to be used as the image of a push notification. It is not supported by all browsers.
Specifies the ISO language of the push notification content in ISO format.
Specifies the whether a user should be renotified.
Specifies if the message is persistent on the screen until a user interacts with it or will only be displayed for several seconds.
Specifies an identifier for a message.
Specifies the timestamp to set for the push message.
Specifies the title to display on the notifications.
Specifies a URL that will be navigated to upon clicking the notification. This can be either a relative path or an explicit path but must exist within the web application. By default, if no URL is set it will navigate to the application root URL.
Specifies the encoded subscription string returned from the user subscribing to the push notifications.
Specifies the delay between the push message being sent and the push notification being displayed to the end user in seconds.
Specifies the priority of the message. When an inactive user comes online notifications are displayed in order of priority and then time sent.
Returns a value if the push notification fails any validations with details of the failure.
Uses the properties to construct a push notification, encrypt it, and send it via HTTP. This requires the Private Key used to create the Vapid Public key as an input parameter.
There are also mandatory properties to be set before sending the notification. These are: SubscriptionObject, ClaimsSubject, ClaimsExpiry, and PushMessageTitle.
Mthroutine Name(Send)
Define_Map For(*INPUT) Class(#xPushManagerSubscriptionStatus) Name(#iStatus) Mandatory(*SQLNULL)
Define_Com Class(#prim_Capi.PrivateKey) Name(#PushPrivateKey)
If (#PushPrivateKey.LoadPemFile( #COM_SELF.GetPrivateKeyPath ))
#Push.PushMessageBadgeUrl := #xPushMessageBadge
#Push.PushMessageBody := #xPushMessageBody
#Push.PushMessageDirection := #xPushMessageDirection
#Push.PushMessageIconUrl := #xPushMessageIcon
#Push.PushMessageImageUrl := #xPushMessageImage
#Push.PushMessageLang := #xPushMessageLanguage
#Push.PushMessageRenotify := #xPushMessageRenotify
#Push.PushMessageRequireAction := #xPushMessageRequireAction
#Push.PushMessageTag := #xPushMessageTag
#Push.PushMessageTimestamp := #xPushMessageTimestamp
#Push.PushMessageTitle := #xPushMessageTitle
#Push.PushMessageUrl := #xPushMessageData
#Push.ClaimsTokenTimespan := #xPushMessageClaimsExpiry
#Push.ClaimsSubject := #xPushMessageClaimsSubject.LowerCase
#Push.SubscriptionObject := #xPushSubscriptionObject
#Push.Urgency := #xPushMessageUrgency
#Push.TimeToLive := #xPushMessageTimeToLive
Select Fields(#xPushSubscriptionObject) From_File(xPushSubscriptions)
#Push.SubscriptionObject := #xPushSubscriptionObject
If (#Push.SendPush( #PushPrivateKey ))
#PushNotificationHttpIsSuccessfulRequest := #Push.HttpResponse.IsSuccessfulRequest
#PushNotificationHttpResponseCode := #Push.HttpResponse.HttpStatusCode
If (#PushNotificationHttpIsSuccessfulRequest.not)
#PushNotificationHttpErrorCode := #Push.HttpResponse.ErrorCode
#PushNotificationHttpErrorMessage := #Push.HttpResponse.ErrorMessage
Endif
Else
#PushNotificationHttpErrorMessage := #Push.ValidationMessage
Endif
Endselect
Endif
Endroutine
The result of applying the features in your PWA is the following: