@attivio/fetch-utils

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This ia a library to use when accessing Attivio REST APIs with SAML-based authentication from a serverless web application such as a React single-page application. It contains a single function, FetchUtils.fetch() which you can use instead of calling the built-in fetch() API directly. This method does a few useful things for you:

• It sets the headers and parameters to the fetch() call in a consistent manner
• It handles cases where the fetch() call fails because of a potentially missing authentication token, redirecting to the special login API call on the servlet to trigger the authentication
• It provides a consistent way to receive results and error messages

Using the Library

To use @attivio/fetch-utils:

1. Add it as a dependency to your project:

npm install --save @attivio/fetch-utils

2. Import the FetchUtils class into your application code where you will need to access the Attivio REST APIs:

import FetchUtils from '@attivio/fetch-utils';

3. Finally, use it to access the REST APIs you need:

const baseUri = 'http://myhost:8080/searchui/';
const restEndpoint = 'rest/serverDetailsApi/user';
const callback = (result: any | null, error: string | null) => {
  if (result) {
    console.log('The API call returned this result', result);
  } else if (error) {
    console.log('The API call returned this error', error);
  }
};

FetchUtils.fetch(baseUri, restEndpoint, null, callback, 'GET', 'An error occured.');

Using the FetchUtils.fetch() Method

The FetchUtils.fetch() method takes the following parameters:

| Parameter | Type | Description | |-----------|------|-------------| | baseUri | string | the base URI for the Attivio servlet, up to and including the servlet context part of the path, including the trailing slash (e.g., /searchui/) | | endpointUri | string | the part of the URI specific to the REST endpoint you want to access | | payload | any | a JavaScript object containing the palyload to pass as parameters to the REST call; will be converted into a JSON string -- pass null if no payload is needed | | callback | function (see below) | the function called when the fetch() call returns a result or an error | | method | HttpMethod (see below) | the HTTP method to use when making the fetch request | | defaultErrorMessage | string | the message that should be passed to the callback if an error occurs but no message can be obtained from the fetch() call |

The callback function is called asynchronosly, once there is either a successful result or an error from the fetch() call. Its parameters are:

| Parameter | Type | Description | |-----------|------|-------------| | result | any | null | a JavaScript object containing the result of a successful fetch() call; if an error occurred, this will be null | | error | string | null | the error message describing what went wrong if the fetch() call didn't succeed; if it did succeed, this will be null |

The type HttpMethod is one of the following strings: 'GET', 'HEAD', 'POST', 'PUT', 'DELETE', 'CONNECT', 'OPTIONS', 'TRACE', or 'PATCH'.