@polkadot/api-provider/http/index.js

Transport providers for the API

"use strict";

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;

require("./polyfill");

var _assert = _interopRequireDefault(require("@polkadot/util/assert"));

var _logger = _interopRequireDefault(require("@polkadot/util/logger"));

var _json = _interopRequireDefault(require("../coder/json"));

// Copyright 2017-2018 @polkadot/api-provider authors & contributors
// This software may be modified and distributed under the terms
// of the ISC license. See the LICENSE file for details.
const ERROR_SUBSCRIBE = 'HTTP Provider does not have subscriptions, use WebSockets instead';
/**
 * @name HttpProvider
 * @summary The HTTP Provider allows sending requests using HTTP to a HTTP RPC server TCP port.
 * @description It does not support subscriptions so you won't be able to listen to events
 * such as new blocks or balance changes. It is usually preferrable using the [[WsProvider]].
 *
 * @example
 * <BR>
 *
 * ```javascript
 * import Api from '@polkadot/api';
 * import HttpProvider from '@polkadot/api-provider/http';
 *
 * const provider = new HttpProvider('http://127.0.0.1:9933');
 * const api = new Api(provider);
 * ```
 *
 * @see [[WsProvider]]
 */

class HttpProvider {
  /**
   * @param {string} endpoint The endpoint url starting with http://
   */
  constructor(endpoint) {
    this.coder = void 0;
    this.endpoint = void 0;
    this.l = void 0;
    (0, _assert.default)(/^(https|http):\/\//.test(endpoint), `Endpoint should start with 'http://', received '${endpoint}'`);
    this.coder = (0, _json.default)();
    this.endpoint = endpoint;
    this.l = (0, _logger.default)('api-http');
  }
  /**
   * @summary Whether the node is connected or not.
   * @return {boolean} true if connected
   */


  isConnected() {
    return true;
  }
  /**
   * @summary Events are not supported with the HttpProvider, see [[WsProvider]].
   * @description HTTP Provider does not have 'on' emitters. WebSockets should be used instead.
   */


  on(type, sub) {
    this.l.error(`HTTP Provider does not have 'on' emitters, use WebSockets instead`);
  }
  /**
   * @summary Send HTTP POST Request with Body to configured HTTP Endpoint.
   */


  async send(method, params) {
    const body = this.coder.encodeJson(method, params);
    const response = await fetch(this.endpoint, {
      body,
      headers: {
        'Accept': 'application/json',
        'Content-Length': `${body.length}`,
        'Content-Type': 'application/json'
      },
      method: 'POST'
    });
    (0, _assert.default)(response.ok, `[${response.status}]: ${response.statusText}`);
    const result = await response.json();
    return this.coder.decodeResponse(result);
  }
  /**
   * @summary Subscriptions are not supported with the HttpProvider, see [[WsProvider]].
   */


  async subscribe(types, method, params, cb) {
    this.l.error(ERROR_SUBSCRIBE);
    throw new Error(ERROR_SUBSCRIBE);
  }
  /**
   * @summary Subscriptions are not supported with the HttpProvider, see [[WsProvider]].
   */


  async unsubscribe(type, method, id) {
    this.l.error(ERROR_SUBSCRIBE);
    throw new Error(ERROR_SUBSCRIBE);
  }

}

exports.default = HttpProvider;