const axios = require('axios');
/**
* Abstract class that provides the common bones for OSDU API clients.
* - Provides the framework for managing authentication and appending required headers to API requests.
* @class
* @abstract
* @category Clients
*/
class BaseOsduClient {
/**
* @constructor
* @param {string} api_url - The url for the OSDU API, with or without a trailing `/`
*/
constructor(api_url) {
if (!api_url) {
throw new Error(`Must provide an API url for the OSDU application`);
}
this.apiUrl = api_url;
if (this.apiUrl[this.apiUrl.length-1] == '/') {
this.apiUrl = this.apiUrl.substr(0, this.apiUrl.length-1);
}
this.axiosClient = axios.create({
baseURL: this.apiUrl
});
}
// Auth
/**
* Refresh the access token used to authenticate API Requests
* - Not implemented in the base class
* @protected
* @throws Error
*/
_refreshAccessToken() {
throw new Error(`_refreshAccessToken is not implemented in BaseOsduClient`);
}
// HTTP Requests
/**
* Generate the HTTP headers needed to interact with the OSDU API
* @protected
* @param {string} data_partition - The data partition against which the request is being made
* @returns {Object} The common headers required to communicate with the OSDU API
*/
_getHeaders(data_partition) {
if (!this.accessToken) {
throw new Error(`OSDU client does not have an access token`);
}
return {
"Content-Type": "application/json",
"data-partition-id": data_partition,
"Authorization": `Bearer ${this.accessToken}`
};
}
/**
* Common logic to all HTTP requests made to the OSDU API
* - For internal client use only
* - Handles the automatic generation of common headers, authentication, and retries (up to 3) on error conditions
* @protected
* @param {string} data_partition - The data partition against which the request is being made
* @param {Function} method - The axios method reference to call when sending the request (`get`, `post`, etc.)
* @param {Object} args - The arguments used to invoke the API request
* @param {string} args.path - The url path to reach out to on the OSDU API (I.E. `/path`)
* @param {Object} [args.body] - The JSON HTTP body to include with the request
* @param {Object} [args.config] - Any additional Axios config to provide with the request. Note that `Content-Type`, `data-partition-id`, and `Authorization` headers will be overwritten
* @param {number} [iteration=1] - The iteration of this request. Used for internal recursion and should not be passed in by an external caller
* @returns {Promise<AxiosResponse>} The response from the Axios client
*/
async _makeRequest(data_partition, method, args, iteration = 1) {
// Set up configuration such as headers
if (!args.config) {
args.config = { headers: {} };
}
if (!this.accessToken) {
await this._refreshAccessToken();
}
args.config.headers = Object.assign(
args.config.headers,
this._getHeaders(data_partition)
);
// Make axios request
var response;
try {
if (args.body) {
response = await method(args.path, args.body, args.config);
}
else {
response = await method(args.path, args.config);
}
}
catch (error) {
if (error.response) {
response = error.response;
}
else {
throw error;
}
}
// Handle response
if (response.status >= 200 && response.status < 300) {
if (response.data) {
return response.data;
}
else {
return true;
}
}
if (response.status == 404) {
return undefined;
}
if (response.status == 401 || response.status == 403) {
await this._refreshAccessToken();
}
if ([401, 403, 500].includes(response.status)) {
// Validate iteration and retry
const maxAttempts = 3;
if (iteration > maxAttempts) {
const err = new Error(`Failed retrying method with the OSDU API: [${response.status}] ${response.statusText}`);
err.response = response;
throw err;
}
else {
return this._makeRequest(data_partition, method, args, iteration+1);
}
}
const err = new Error(`Invalid response code from the OSDU API: [${response.status}] ${response.statusText}`);
err.response = response;
throw err;
}
/**
* Convenience method for invoking HTTP POST requests
* @param {string} path - The url path for the HTTP POST request (I.E. `/path`)
* @param {Object} body - The JSON body to send with the HTTP POST request
* @param {string} data_partition - The data partition against which the request is being made
* @returns {Promise<Object>} The response data from the Axios client
*/
post(path, body, data_partition) {
return this._makeRequest(data_partition, this.axiosClient.post, { path, body });
}
/**
* Convenience method for invoking HTTP PUT requests
* @param {string} path - The url path for the HTTP PUT request (I.E. `/path`)
* @param {Object} body - The JSON body to send with the HTTP PUT request
* @param {string} data_partition - The data partition against which the request is being made
* @returns {Promise<Object>} The response data from the Axios client
*/
put(path, body, data_partition) {
return this._makeRequest(data_partition, this.axiosClient.put, { path, body });
}
/**
* Convenience method for invoking HTTP GET requests
* @param {string} path - The url path for the HTTP GET request (I.E. `/path`)
* @param {string} data_partition - The data partition against which the request is being made
* @returns {Promise<Object>} The response data from the Axios client
*/
get(path, data_partition) {
return this._makeRequest(data_partition, this.axiosClient.get, { path });
}
/**
* Convenience method for invoking HTTP DELETE requests
* @param {string} path - The url path for the HTTP DELETE request (I.E. `/path`)
* @param {string} data_partition - The data partition against which the request is being made
* @returns {Promise<Object>} The response data from the Axios client
*/
delete(path, data_partition) {
return this._makeRequest(data_partition, this.axiosClient.delete, { path });
}
}
module.exports = BaseOsduClient;Source