@near-js/accounts/lib/esm/local-view-execution/index.js

Classes encapsulating account-specific functionality

import { printTxOutcomeLogs } from "@near-js/utils";
import { Storage } from "./storage.js";
import { Runtime } from "./runtime.js";
import { viewState } from "../utils.js";
class LocalViewExecution {
  connection;
  storage;
  constructor(connection) {
    this.connection = connection.getConnection();
    this.storage = new Storage();
  }
  async fetchContractCode(contractId, blockQuery) {
    const result = await this.connection.provider.query({
      request_type: "view_code",
      account_id: contractId,
      ...blockQuery
    });
    return result.code_base64;
  }
  async fetchContractState(contractId, blockQuery) {
    return viewState(this.connection, contractId, "", blockQuery);
  }
  async fetch(contractId, blockQuery) {
    const block = await this.connection.provider.block(blockQuery);
    const blockHash = block.header.hash;
    const blockHeight = block.header.height;
    const blockTimestamp = block.header.timestamp;
    const contractCode = await this.fetchContractCode(contractId, blockQuery);
    const contractState = await this.fetchContractState(contractId, blockQuery);
    return {
      blockHash,
      blockHeight,
      blockTimestamp,
      contractCode,
      contractState
    };
  }
  async loadOrFetch(contractId, blockQuery) {
    const stored = this.storage.load(blockQuery);
    if (stored) {
      return stored;
    }
    const { blockHash, ...fetched } = await this.fetch(contractId, blockQuery);
    this.storage.save(blockHash, fetched);
    return fetched;
  }
  /**
   * Calls a view function on a contract, fetching the contract code and state if needed.
   * @param options Options for calling the view function.
   * @param options.contractId The contract account ID.
   * @param options.methodName The name of the view function to call.
   * @param options.args The arguments to pass to the view function.
   * @param options.blockQuery The block query options.
   * @returns {Promise<any>} - A promise that resolves to the result of the view function.
   */
  async viewFunction({ contractId, methodName, args = {}, blockQuery = { finality: "optimistic" } }) {
    const methodArgs = JSON.stringify(args);
    const { contractCode, contractState, blockHeight, blockTimestamp } = await this.loadOrFetch(
      contractId,
      blockQuery
    );
    const runtime = new Runtime({ contractId, contractCode, contractState, blockHeight, blockTimestamp, methodArgs });
    const { result, logs } = await runtime.execute(methodName);
    if (logs) {
      printTxOutcomeLogs({ contractId, logs });
    }
    return JSON.parse(Buffer.from(result).toString());
  }
}
export {
  LocalViewExecution
};