Historian for a particular participant - node.js

Question

Is there any way in which I can get Historian for a particular participant in hyperledger-composer using node API?
I am developing an application based on hyperledger-composer using Node APIs.I want to show the history of transaction of a particular participant in his/her profile. I have created the permission.acl for that and that is working fine in playground. But when i am accessing the historian from node API it is giving complete historian of the network. I don't know how to filter that for a participant.

Answer 1

you can return results from REST API calls since v0.20 to the calling client application, so something like the following would work (not tested, but you get the idea). NOTE: You could just call the REST API end (/GET Trader) direct via REST with your parameter (or whatever endpoints you create for your own business network - the example below is trade-network), rather than the example of using 'READ-ONLY' Transaction processor Endpoint described below, for returning larger result sets to your client application. See more on this in the docs
NODE JS Client using APIs:
const BusinessNetworkConnection = require('composer-client').BusinessNetworkConnection;
const rp = require('request-promise');
this.bizNetworkConnection = new BusinessNetworkConnection();
this.cardName ='admin#mynet';
this.businessNetworkIdentifier = 'mynet';
this.bizNetworkConnection.connect(this.cardName)
.then((result) => {
//You can do ANYTHING HERE eg.
})
.catch((error) => {
throw error;
});
// set up my read only transaction object - find the history of a particular Participant - note it could equally be an Asset instead !
var obj = {
"$class": "org.example.trading.MyPartHistory",
"tradeId": "P1"
};
async function callPartHistory() {
var options = {
method: 'POST',
uri: 'http://localhost:3000/api/MyPartHistory',
body: obj,
json: true
};
let results = await rp(options);
// console.log("Return value from REST API is " + results);
console.log(" ");
console.log(`PARTICIPANT HISTORY for Asset ID: ${results[0].tradeId} is: `);
console.log("=============================================");
for (const part of results) {
console.log(`${part.tradeId} ${part.name}` );
}
}
// Main
callPartHistory();
//
MODEL FILE
#commit(false)
#returns(Trader[])
transaction MyPartHistory {
o String tradeId
}
READ-ONLY TRANSACTION PROCESSOR CODE (in 'logic.js') :
/**
* Sample read-only transaction
* #param {org.example.trading.MyPartHistory} tx
* #returns {org.example.trading.Trader[]} All trxns
* #transaction
*/
async function participantHistory(tx) {
const partId = tx.tradeid;
const nativeSupport = tx.nativeSupport;
// const partRegistry = await getParticipantRegistry('org.example.trading.Trader')
const nativeKey = getNativeAPI().createCompositeKey('Asset:org.example.trading.Trader', [partId]);
const iterator = await getNativeAPI().getHistoryForKey(nativeKey);
let results = [];
let res = {done : false};
while (!res.done) {
res = await iterator.next();
if (res && res.value && res.value.value) {
let val = res.value.value.toString('utf8');
if (val.length > 0) {
console.log("#debug val is " + val );
results.push(JSON.parse(val));
}
}
if (res && res.done) {
try {
iterator.close();
}
catch (err) {
}
}
}
var newArray = [];
for (const item of results) {
newArray.push(getSerializer().fromJSON(item));
}
console.log("#debug the results to be returned are as follows: ");
return newArray; // returns something to my NodeJS client (called via REST API)
}