PKG -- [transport-http] Add Event DataProvider

packages/transport-http/src/subscribe/handlers/events.ts

@@ -0,0 +1,104 @@
+import {SdkTransport} from "@onflow/typedefs"
+import {createSubscriptionHandler} from "./types"
+
+type EventsArgs =
+  SdkTransport.SubscriptionArguments<SdkTransport.SubscriptionTopic.EVENTS>
+
+type EventsData =
+  SdkTransport.SubscriptionData<SdkTransport.SubscriptionTopic.EVENTS>
+
+export type EventsArgsDto = (
+  | {
+      start_block_id: string
+    }
+  | {
+      start_block_height: number
+    }
+  | {}
+) & {
+  event_types?: string[]
+  addresses?: string[]
+  contracts?: string[]
+}
+
+type EventsDataDto = {
+  block_id: string
+  block_height: number
+  block_timestamp: string
+  type: string
+  transaction_id: string
+  transaction_index: number
+  event_index: number
+  payload: string
+}
+
+export const eventsHandler = createSubscriptionHandler<{
+  Topic: SdkTransport.SubscriptionTopic.EVENTS
+  Args: EventsArgs
+  Data: EventsData
+  ArgsDto: EventsArgsDto
+  DataDto: EventsDataDto
+}>({
+  topic: SdkTransport.SubscriptionTopic.EVENTS,
+  createSubscriber: (initialArgs, onData, onError) => {
+    let resumeArgs: EventsArgs = {
+      ...initialArgs,
+    }
+
+    return {
+      onData(rawData: EventsDataDto) {
+        // Parse the raw data
+        const result: EventsData = {
+          event: {
+            blockId: rawData.block_id,
+            blockHeight: rawData.block_height,
+            blockTimestamp: rawData.block_timestamp,
+            type: rawData.type,
+            transactionId: rawData.transaction_id,
+            transactionIndex: rawData.transaction_index,
+            eventIndex: rawData.event_index,
+            payload: rawData.payload,
+          },
+        }
+
+        // Update the resume args
+        resumeArgs = {
+          ...resumeArgs,
+          startBlockHeight: result.event.blockHeight + 1,
+          startBlockId: undefined,
+        }
+
+        onData(result)
+      },
+      onError(error: Error) {
+        onError(error)
+      },
+      argsToDto(args: EventsArgs) {
+        let encodedArgs: EventsArgsDto = {
+          event_types: args.filter?.eventTypes,
+          addresses: args.filter?.addresses,
+          contracts: args.filter?.contracts,
+        }
+
+        if ("startBlockHeight" in args) {
+          return {
+            ...encodedArgs,
+            start_block_height: args.startBlockHeight,
+          }
+        }
+
+        if ("startBlockId" in args) {
+          return {
+            ...encodedArgs,
+            start_block_id: args.startBlockId,
+          }
+        }
+
+        return encodedArgs
+      },
+      get connectionArgs() {
+        return resumeArgs
+      },
+    }
+  },
+})

packages/transport-http/src/subscribe/subscribe.ts

@@ -2,8 +2,13 @@ import {SdkTransport} from "@onflow/typedefs"
 import {SubscriptionManager} from "./subscription-manager"
 import {blocksHandler} from "./handlers/blocks"
 import {blockDigestsHandler} from "./handlers/block-digests"
+import {eventsHandler} from "./handlers/events"
 
-const SUBSCRIPTION_HANDLERS = [blocksHandler, blockDigestsHandler]
+const SUBSCRIPTION_HANDLERS = [
+  blocksHandler,
+  blockDigestsHandler,
+  eventsHandler,
+]
 
 // Map of SubscriptionManager instances by access node URL
 let subscriptionManagerMap: Map<

packages/typedefs/src/sdk-transport/subscriptions.ts

@@ -1,4 +1,4 @@
-import {Block, BlockDigest} from ".."
+import {Block, BlockDigest, Event, EventFilter} from ".."
 
 export type SubscriptionSchema = {
   [SubscriptionTopic.BLOCKS]: SchemaItem<
@@ -13,11 +13,31 @@ export type SubscriptionSchema = {
       blockDigest: BlockDigest
     }
   >
+  [SubscriptionTopic.EVENTS]: SchemaItem<
+    // TODO: We do not know the data model types yet
+    (
+      | {
+          startBlockId: string
+        }
+      | {
+          startBlockHeight: number
+        }
+      | {}
+    ) & {
+      filter: EventFilter
+    },
+    {
+      event: Omit<Event, "data"> & {
+        payload: string
+      }
+    }
+  >
 }
 
 export enum SubscriptionTopic {
   BLOCKS = "blocks",
   BLOCK_DIGESTS = "block_digests",
+  EVENTS = "events",
 }
 
 type BlockArgs =