Resolve the DDO using the service endpoint on registration event.

src/aquarius/Aquarius.ts

@@ -178,11 +178,16 @@ export class Aquarius extends Instantiable {
 
     /**
      * Retrieves a DDO by DID.
-     * @param  {DID} did DID of the asset.
+     * @param  {DID | string} did DID of the asset.
      * @return {Promise<DDO>} DDO of the asset.
      */
-    public async retrieveDDO(did: DID): Promise<DDO> {
+    public async retrieveDDO(
-        const fullUrl = `${this.url}${apiPath}/${did.getDid()}`
+        did: DID | string,
+        metadataServiceEndpoint?: string
+    ): Promise<DDO> {
+        did = did && DID.parse(did)
+        const fullUrl =
+            metadataServiceEndpoint || `${this.url}${apiPath}/${did.getDid()}`
         const result = await this.ocean.utils.fetch
             .get(fullUrl)
             .then((response: any) => {
@@ -208,6 +213,10 @@ export class Aquarius extends Instantiable {
         return result
     }
 
+    public async retrieveDDOByUrl(metadataServiceEndpoint?: string) {
+        return this.retrieveDDO(undefined, metadataServiceEndpoint)
+    }
+
     public getServiceEndpoint(did: DID) {
         return `${this.url}/api/v1/aquarius/assets/ddo/did:op:${did.getId()}`
     }

src/keeper/contracts/DIDRegistry.ts

@@ -1,6 +1,6 @@
 import Web3Provider from '../Web3Provider'
 import ContractBase from './ContractBase'
-import { zeroX, didPrefixed } from '../../utils'
+import { zeroX, didPrefixed, didZeroX } from '../../utils'
 import { InstantiableConfig } from '../../Instantiable.abstract'
 
 export default class DIDRegistry extends ContractBase {
@@ -42,4 +42,24 @@ export default class DIDRegistry extends ContractBase {
             .map(({ returnValues }) => returnValues._did)
             .map(didPrefixed)
     }
+
+    public async getAttributesByDid(
+        did: string
+    ): Promise<{ did: string; serviceEndpoint: string; checksum: string }> {
+        return (await this.getPastEvents('DIDAttributeRegistered', {
+            _did: didZeroX(did)
+        })).map(
+            ({
+                returnValues: {
+                    _did,
+                    _checksum: checksum,
+                    _value: serviceEndpoint
+                }
+            }) => ({
+                did: didPrefixed(_did),
+                serviceEndpoint,
+                checksum
+            })
+        )[0]
+    }
 }

src/ocean/DID.ts

@@ -11,7 +11,10 @@ export default class DID {
      * @param  {string} didString DID in string.
      * @return {DID}
      */
-    public static parse(didString: string): DID {
+    public static parse(didString: string | DID): DID {
+        if (didString instanceof DID) {
+            didString = didString.getDid()
+        }
         let did: DID
         const didMatch = didString.match(/^did:op:([a-f0-9]{64})$/i)
 

src/ocean/OceanAssets.ts

@@ -53,8 +53,10 @@ export class OceanAssets extends Instantiable {
      * @return {Promise<DDO>}
      */
     public async resolve(did: string): Promise<DDO> {
-        const d: DID = DID.parse(did)
+        const {
-        return this.ocean.aquarius.retrieveDDO(d)
+            serviceEndpoint
+        } = await this.ocean.keeper.didRegistry.getAttributesByDid(did)
+        return this.ocean.aquarius.retrieveDDOByUrl(serviceEndpoint)
     }
 
     /**