5.4.3.17 Chaincode and block event notification API

This interface is implemented on the off-BSN system side. When the PCN gateway receives the notification of a triggered event, it uses this interface to notify the off-BSN system about the execution result.

After receiving the notification successfully, the off-BSN system returns a string containing “success”, otherwise, the gateway will send the notification again at 3, 12, 27, and 48 seconds respectively, for a total of five times.

1. Call method: POST

2. Signature algorithm: required and refer to Section 5.4.3.1

3. Call parameters

No. Field name Field Type Required Remarks
1 Header header Map Y
2 Body body Map N
3 Signature Value mac String Y
header
1 user unique ID userCode String Y
2 DApp unique ID appCode String Y
body
1 Chaincode ID chainCode String N Null when the block event notification
2 PCN ID orgCode String Y
3 Registered Event key eventKey String N
4 Registered Event ID eventId String Y
5 Registered Event parameters attachArgs String N Additional parameters entered during registration
6 Monitored event key eventName String N The event name in the chaincode, null when the block event notification
7 Current Chaincode transaction Id txId String N Null when the block event notification
8 Monitored event value payload String N
9 Current Block Height blockNumber Long Y
10 Response random string nonceStr String Y Off-BSN system uses this value to judge if the notification is already received. This string remains the same at the repeated notifications.
11 Previous hash previousHash String N Null when chaincode event notification

Example:

Chaincode event nofitication
{"header":{"userCode":"lessing","appCode":"CL20191107112252"},"body":{"chainCode":"cc_bsn_test_00","orgCode":"ORG1571365934172","eventKey":"test:\\S{32}","eventId":"2964a0f60b3e460f834618b3664af2da","attachArgs":"abc=123211","eventName":"test:12345678123456781234567812345678","txId":"32fc105681820fa556b8a460efc1e43a47daa864b959ea1753abb4640f2dce49","payload":"","blockNumber":74,"nonceStr":"522c8061b5e84837bad72ca08c6a353f"},"mac":"MEQCIDU4tROyjLtvD1b8TTbWWAlCPuUbmdPAEUXwRRgVn7kIAiA58je5u/7xDuRPcgeUWL3nB9mouUGQ6dGKJMmD7Jm08g=="}
Block event notification
{"header":{"userCode":"USER0001202007101641243516163","appCode":"app0001202101191411238426266"},"body":{"orgCode":"ORG2020041114171692360","eventId":"8746bb9a1e854c9f8b3710f5a63f7c59","attachArgs":"a=1","previousHash":"022281f6089e3684501251775166b6b0afd18a176ec98a835cb5d09aff0d4950","blockNumber":12,"nonceStr":"79a7baa26c854caeb2e2e7abc0b7f07e"},"mac":"MEUCIQDiZrwf8fKG/3fuaVrsfTN3BKmLx+qnnEuuSaHfvIBbMQIgS+1qHKXeVR24WXwOGu3Nze/tLLziQ0LkjXaueYu0ctM="}

4. The payload parameter in the message is not passed in Fabric 1.4.3, please refer to https://github.com/hyperledger/fabric/blob/v1.4.3/core/peer/deliverevents.go#L251

For the specific code, if you need to use the payload parameter, you can get it as follows:

1) store the content to be passed through the event to the chain in the form of “key-value”.

2) pass the event name and the key splice in 1 as eventName, e.g.: eventkey_key.

3) register the event with a regular registration, e.g. : eventkey_[\s\S]*.

4) after receiving the event, parse the key according to the event name and call a query to get the value.

5) if the amount of payload data to be passed is not large, it can be directly spliced to enevtName, which has no length limitation.

© 2019-2021 Red Date (Hong Kong) Technology Limited. all right reserved,powered by GitbookFile Modify: 2022-05-05 15:59:00

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