Added js asset-transfer-ledger query sample

Based off of marbles02.js, variable and function names were renamed, but the logic of the code is the same.
Added AssetExists()

Signed-off-by: r2roC <arturo@IBM.com>

asset-transfer-ledger-queries/chaincode-javascript/.gitignore

@@ -0,0 +1,77 @@
+#
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asset-transfer-ledger-queries/chaincode-javascript/META-INF/statedb/couchdb/indexes/indexOwner.json

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+{"index":{"fields":["docType","owner"]},"ddoc":"indexOwnerDoc", "name":"indexOwner","type":"json"}

asset-transfer-ledger-queries/chaincode-javascript/asset_transfer_ledger_chaincode.js

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+/*
+# Copyright IBM Corp. All Rights Reserved.
+#
+# SPDX-License-Identifier: Apache-2.0
+*/
+
+'use strict';
+const shim = require('fabric-shim');
+const util = require('util');
+
+let Chaincode = class {
+  async Init(stub) {
+    let ret = stub.getFunctionAndParameters();
+    console.info(ret);
+    console.info('=========== Instantiated Asset Chaincode ===========');
+    return shim.success();
+  }
+
+  async Invoke(stub) {
+    console.info('Transaction ID: ' + stub.getTxID());
+    console.info(util.format('Args: %j', stub.getArgs()));
+
+    let ret = stub.getFunctionAndParameters();
+    console.info(ret);
+
+    let method = this[ret.fcn];
+    if (!method) {
+      console.log('no function of name:' + ret.fcn + ' found');
+      throw new Error('Received unknown function ' + ret.fcn + ' invocation');
+    }
+    try {
+      let payload = await method(stub, ret.params, this);
+      return shim.success(payload);
+    } catch (err) {
+      console.log(err);
+      return shim.error(err);
+    }
+  }
+
+  // ===============================================
+  // createAsset - create a new Asset
+  // ===============================================
+  async createAsset(stub, args, thisClass) {
+    if (args.length != 4) {
+      throw new Error('Incorrect number of arguments. Expecting 4');
+    }
+    // ==== Input sanitation ====
+    console.info('--- start init Asset ---')
+    if (args[0].lenth <= 0) {
+      throw new Error('1st argument must be a non-empty string');
+    }
+    if (args[1].lenth <= 0) {
+      throw new Error('2nd argument must be a non-empty string');
+    }
+    if (args[2].lenth <= 0) {
+      throw new Error('3rd argument must be a non-empty string');
+    }
+    if (args[3].lenth <= 0) {
+      throw new Error('4th argument must be a non-empty string');
+    }
+    let assetName = args[0];
+    let color = args[1].toLowerCase();
+    let owner = args[3].toLowerCase();
+    let size = parseInt(args[2]);
+    if (typeof size !== 'number') {
+      throw new Error('3rd argument must be a numeric string');
+    }
+
+    const assetExists = thisClass["assetExists"]
+    const exists = await assetExists(stub, assetName)
+    if (exists) {
+      throw new Error('')
+    }
+
+    // ==== Create asset object and marshal to JSON ====
+    let asset = {};
+    asset.docType = 'asset';
+    asset.name = assetName;
+    asset.color = color;
+    asset.size = size;
+    asset.owner = owner;
+
+    // === Save asset to state ===
+    await stub.putState(assetName, Buffer.from(JSON.stringify(asset)));
+    let indexName = 'color~name'
+    let colorNameIndexKey = await stub.createCompositeKey(indexName, [asset.color, asset.name]);
+    console.info(colorNameIndexKey);
+    //  Save index entry to state. Only the key name is needed, no need to store a duplicate copy of the marble.
+    //  Note - passing a 'nil' value will effectively delete the key from state, therefore we pass null character as value
+    await stub.putState(colorNameIndexKey, Buffer.from('\u0000'));
+    // ==== asset saved and indexed. Return success ====
+    console.info('- end init asset');
+  }
+
+  async assetExists(stub, assetName) {
+    // ==== Check if asset already exists ====
+    let assetState = await stub.getState(assetName);
+    if ( !assetState || assetState.length === 0 ) {
+      return false;
+    }
+    return true
+  }
+
+  // ===============================================
+  // ReadAsset - read a asset from chaincode state
+  // ===============================================
+  async ReadAsset(stub, args, thisClass) {
+    if (args.length != 1) {
+      throw new Error('Incorrect number of arguments. Expecting name of the asset to query');
+    }
+
+    let name = args[0];
+    if (!name) {
+      throw new Error(' asset name must not be empty');
+    }
+    let assetAsbytes = await stub.getState(name); //get the asset from chaincode state
+    if (!assetAsbytes.toString()) {
+      let jsonResp = {};
+      jsonResp.Error = 'Asset does not exist: ' + name;
+      throw new Error(JSON.stringify(jsonResp));
+    }
+    console.info('=======================================');
+    console.log(assetAsbytes.toString());
+    console.info('=======================================');
+    return assetAsbytes;
+  }
+
+  // ==================================================
+  // delete - remove a asset key/value pair from state
+  // ==================================================
+  async delete(stub, args, thisClass) {
+    if (args.length != 1) {
+      throw new Error('Incorrect number of arguments. Expecting name of the asset to delete');
+    }
+    let assetName = args[0];
+    if (!assetName) {
+      throw new Error('asset name must not be empty');
+    }
+
+    exists = await assetExists(stub, assetName)
+    if (!exists) {
+      throw new Error('')
+    }
+
+    // to maintain the color~name index, we need to read the asset first and get its color
+    let valAsbytes = await stub.getState(assetName); //get the asset from chaincode state
+    let jsonResp = {};
+    if (!valAsbytes) {
+      jsonResp.error = 'asset does not exist: ' + name;
+      throw new Error(jsonResp);
+    }
+    let assetJSON = {};
+    try {
+      assetJSON = JSON.parse(valAsbytes.toString());
+    } catch (err) {
+      jsonResp = {};
+      jsonResp.error = 'Failed to decode JSON of: ' + assetName;
+      throw new Error(jsonResp);
+    }
+
+    await stub.deleteState(assetName); //remove the asset from chaincode state
+
+    // delete the index
+    let indexName = 'color~name';
+    let colorNameIndexKey = stub.createCompositeKey(indexName, [assetJSON.color, assetJSON.name]);
+    if (!colorNameIndexKey) {
+      throw new Error(' Failed to create the createCompositeKey');
+    }
+    //  Delete index entry to state.
+    await stub.deleteState(colorNameIndexKey);
+  }
+
+  // ===========================================================
+  // transfer a asset by setting a new owner name on the asset
+  // ===========================================================
+  async transferAsset(stub, args, thisClass) {
+    //   0       1
+    // 'name', 'bob'
+    if (args.length < 2) {
+      throw new Error('Incorrect number of arguments. Expecting assetname and owner')
+    }
+
+    let assetName = args[0];
+    let newOwner = args[1].toLowerCase();
+    console.info('- start transferAsset ', assetName, newOwner);
+
+    let assetAsBytes = await stub.getState(assetName);
+    if (!assetAsBytes || !assetAsBytes.toString()) {
+      throw new Error('asset does not exist');
+    }
+    let assetToTransfer = {};
+    try {
+      assetToTransfer = JSON.parse(assetAsBytes.toString()); //unmarshal
+    } catch (err) {
+      let jsonResp = {};
+      jsonResp.error = 'Failed to decode JSON of: ' + assetName;
+      throw new Error(jsonResp);
+    }
+    console.info(assetToTransfer);
+    assetToTransfer.owner = newOwner; //change the owner
+
+    let assetJSONasBytes = Buffer.from(JSON.stringify(assetToTransfer));
+    await stub.putState(assetName, assetJSONasBytes); //rewrite the asset
+
+    console.info('- end transferAsset (success)');
+  }
+
+  // ===========================================================================================
+  // getAssetsByRange performs a range query based on the start and end keys provided.
+
+  // Read-only function results are not typically submitted to ordering. If the read-only
+  // results are submitted to ordering, or if the query is used in an update transaction
+  // and submitted to ordering, then the committing peers will re-execute to guarantee that
+  // result sets are stable between endorsement time and commit time. The transaction is
+  // invalidated by the committing peers if the result set has changed between endorsement
+  // time and commit time.
+  // Therefore, range queries are a safe option for performing update transactions based on query results.
+  // ===========================================================================================
+  async getAssetsByRange(stub, args, thisClass) {
+
+    if (args.length < 2) {
+      throw new Error('Incorrect number of arguments. Expecting 2');
+    }
+
+    let startKey = args[0];
+    let endKey = args[1];
+
+    let resultsIterator = await stub.getStateByRange(startKey, endKey);
+    let method = thisClass['getAllResults'];
+    let results = await method(resultsIterator, false);
+
+    return Buffer.from(JSON.stringify(results));
+  }
+
+  // ==== Example: GetStateByPartialCompositeKey/RangeQuery =========================================
+  // transferAssetsBasedOnColor will transfer assets of a given color to a certain new owner.
+  // Uses a GetStateByPartialCompositeKey (range query) against color~name 'index'.
+  // Committing peers will re-execute range queries to guarantee that result sets are stable
+  // between endorsement time and commit time. The transaction is invalidated by the
+  // committing peers if the result set has changed between endorsement time and commit time.
+  // Therefore, range queries are a safe option for performing update transactions based on query results.
+  // ===========================================================================================
+  async transferAssetsBasedOnColor(stub, args, thisClass) {
+
+    //   0       1
+    // 'color', 'bob'
+    if (args.length < 2) {
+      throw new Error('Incorrect number of arguments. Expecting color and owner');
+    }
+
+    let color = args[0];
+    let newOwner = args[1].toLowerCase();
+    console.info('- start transferAssetsBasedOnColor ', color, newOwner);
+
+    // Query the color~name index by color
+    // This will execute a key range query on all keys starting with 'color'
+    let coloredAssetResultsIterator = await stub.getStateByPartialCompositeKey('color~name', [color]);
+
+    let method = thisClass['transferAsset'];
+    // Iterate through result set and for each asset found, transfer to newOwner
+    while (true) {
+      let responseRange = await coloredAssetResultsIterator.next();
+      if (!responseRange || !responseRange.value || !responseRange.value.key) {
+        return;
+      }
+      console.log(responseRange.value.key);
+
+      // let value = res.value.value.toString('utf8');
+      let objectType;
+      let attributes;
+      ({
+        objectType,
+        attributes
+      } = await stub.splitCompositeKey(responseRange.value.key));
+
+      let returnedColor = attributes[0];
+      let returnedAssetName = attributes[1];
+      console.info(util.format('- found a asset from index:%s color:%s name:%s\n', objectType, returnedColor, returnedAssetName));
+
+      // Now call the transfer function for the found asset.
+      // Re-use the same function that is used to transfer individual assets
+      let response = await method(stub, [returnedAssetName, newOwner]);
+    }
+
+    let responsePayload = util.format('Transferred %s assets to %s', color, newOwner);
+    console.info('- end transferAssetsBasedOnColor: ' + responsePayload);
+  }
+
+
+  // ===== Example: Parameterized rich query =================================================
+  // queryAssetsByOwner queries for assets based on a passed in owner.
+  // This is an example of a parameterized query where the query logic is baked into the chaincode,
+  // and accepting a single query parameter (owner).
+  // Only available on state databases that support rich query (e.g. CouchDB)
+  // =========================================================================================
+  async queryAssetsByOwner(stub, args, thisClass) {
+    //   0
+    // 'bob'
+    if (args.length < 1) {
+      throw new Error('Incorrect number of arguments. Expecting owner name.')
+    }
+
+    let owner = args[0].toLowerCase();
+    let queryString = {};
+    queryString.selector = {};
+    queryString.selector.docType = 'asset';
+    queryString.selector.owner = owner;
+    let method = thisClass['getQueryResultForQueryString'];
+    let queryResults = await method(stub, JSON.stringify(queryString), thisClass);
+    return queryResults; //shim.success(queryResults);
+  }
+
+  // ===== Example: Ad hoc rich query ========================================================
+  // queryAssets uses a query string to perform a query for assets.
+  // Query string matching state database syntax is passed in and executed as is.
+  // Supports ad hoc queries that can be defined at runtime by the client.
+  // If this is not desired, follow the queryAssetsForOwner example for parameterized queries.
+  // Only available on state databases that support rich query (e.g. CouchDB)
+  // =========================================================================================
+  async queryAssets(stub, args, thisClass) {
+    //   0
+    // 'queryString'
+    if (args.length < 1) {
+      throw new Error('Incorrect number of arguments. Expecting queryString');
+    }
+    let queryString = args[0];
+    if (!queryString) {
+      throw new Error('queryString must not be empty');
+    }
+    let method = thisClass['getQueryResultForQueryString'];
+    let queryResults = await method(stub, queryString, thisClass);
+    return queryResults;
+  }
+
+  async getAllResults(iterator, isHistory) {
+    let allResults = [];
+    while (true) {
+      let res = await iterator.next();
+
+      if (res.value && res.value.value.toString()) {
+        let jsonRes = {};
+        console.log(res.value.value.toString('utf8'));
+
+        if (isHistory && isHistory === true) {
+          jsonRes.TxId = res.value.tx_id;
+          jsonRes.Timestamp = res.value.timestamp;
+          jsonRes.IsDelete = res.value.is_delete.toString();
+          try {
+            jsonRes.Value = JSON.parse(res.value.value.toString('utf8'));
+          } catch (err) {
+            console.log(err);
+            jsonRes.Value = res.value.value.toString('utf8');
+          }
+        } else {
+          jsonRes.Key = res.value.key;
+          try {
+            jsonRes.Record = JSON.parse(res.value.value.toString('utf8'));
+          } catch (err) {
+            console.log(err);
+            jsonRes.Record = res.value.value.toString('utf8');
+          }
+        }
+        allResults.push(jsonRes);
+      }
+      if (res.done) {
+        console.log('end of data');
+        await iterator.close();
+        console.info(allResults);
+        return allResults;
+      }
+    }
+  }
+
+  // =========================================================================================
+  // getQueryResultForQueryString executes the passed in query string.
+  // Result set is built and returned as a byte array containing the JSON results.
+  // =========================================================================================
+  async getQueryResultForQueryString(stub, queryString, thisClass) {
+
+    console.info('- getQueryResultForQueryString queryString:\n' + queryString)
+    let resultsIterator = await stub.getQueryResult(queryString);
+    let method = thisClass['getAllResults'];
+
+    let results = await method(resultsIterator, false);
+
+    return Buffer.from(JSON.stringify(results));
+  }
+
+  async getHistoryForAsset(stub, args, thisClass) {
+
+    if (args.length < 1) {
+      throw new Error('Incorrect number of arguments. Expecting 1')
+    }
+    let assetName = args[0];
+    console.info('- start getHistoryForAsset: %s\n', assetName);
+
+    let resultsIterator = await stub.getHistoryForKey(assetName);
+    let method = thisClass['getAllResults'];
+    let results = await method(resultsIterator, true);
+
+    return Buffer.from(JSON.stringify(results));
+  }
+
+  // ====== Pagination =========================================================================
+  // Pagination provides a method to retrieve records with a defined pagesize and
+  // start point (bookmark).  An empty string bookmark defines the first "page" of a query
+  // result. Paginated queries return a bookmark that can be used in
+  // the next query to retrieve the next page of results. Paginated queries extend
+  // rich queries and range queries to include a pagesize and bookmark.
+  //
+  // Two examples are provided in this example. The first is getAssetsByRangeWithPagination
+  // which executes a paginated range query.
+  // The second example is a paginated query for rich ad-hoc queries.
+  // =========================================================================================
+
+  // ====== Example: Pagination with Range Query ===============================================
+  // getAssetsByRangeWithPagination performs a range query based on the start & end key,
+  // page size and a bookmark.
+  //
+  // The number of fetched records will be equal to or lesser than the page size.
+  // Paginated range queries are only valid for read only transactions.
+  // ===========================================================================================
+  async getAssetsByRangeWithPagination(stub, args, thisClass) {
+    if (args.length < 2) {
+      throw new Error('Incorrect number of arguments. Expecting 2');
+    }
+    const startKey = args[0];
+    const endKey = args[1];
+
+    const pageSize = parseInt(args[2], 10);
+    const bookmark = args[3];
+
+    const { iterator, metadata } = await stub.getStateByRangeWithPagination(startKey, endKey, pageSize, bookmark);
+    const getAllResults = thisClass['getAllResults'];
+    const results = await getAllResults(iterator, false);
+    // use RecordsCount and Bookmark to keep consistency with the go sample
+    results.ResponseMetadata = {
+      RecordsCount: metadata.fetched_records_count,
+      Bookmark: metadata.bookmark,
+    };
+    return Buffer.from(JSON.stringify(results));
+  }
+
+  // =========================================================================================
+  // getQueryResultForQueryStringWithPagination executes the passed in query string with
+  // pagination info. Result set is built and returned as a byte array containing the JSON results.
+  // =========================================================================================
+  async queryAssetsWithPagination(stub, args, thisClass) {
+
+    //   0
+    // "queryString"
+    if (args.length < 3) {
+      return shim.Error("Incorrect number of arguments. Expecting 3")
+    }
+
+    const queryString = args[0];
+    const pageSize = parseInt(args[1], 10);
+    const bookmark = args[2];
+
+    const { iterator, metadata } = await stub.getQueryResultWithPagination(queryString, pageSize, bookmark);
+    const getAllResults = thisClass['getAllResults'];
+    const results = await getAllResults(iterator, false);
+    // use RecordsCount and Bookmark to keep consistency with the go sample
+    results.ResponseMetadata = {
+      RecordsCount: metadata.fetched_records_count,
+      Bookmark: metadata.bookmark,
+    };
+
+    return Buffer.from(JSON.stringify(results));
+  }
+};
+
+shim.start(new Chaincode());

asset-transfer-ledger-queries/chaincode-javascript/package.json

@@ -0,0 +1,17 @@
+{
+	"name": "assets",
+	"version": "1.0.0",
+	"description": "asset chaincode implemented in node.js",
+	"engines": {
+		"node": ">=8.4.0",
+		"npm": ">=5.3.0"
+	},
+	"scripts": {
+		"start": "node asset_transfer_ledger_chaincode.js"
+	},
+	"engine-strict": true,
+	"license": "Apache-2.0",
+	"dependencies": {
+		"fabric-shim": "^2.0.0"
+	}
+}