Manage iframe Embedded Content Session State using enigma.js and JSON web tokens

Contributed by Daniel Pilla

Overview

In this tutorial, you are going to learn how to embed an iframe and monitor its session state when using JSON web tokens (JWTs) for authorization to Qlik Cloud.

Note: This tutorial contains sample code using JWTs for authorization. If you are using OpenID Connect (OIDC), refer to this tutorial.

Context

You are embedding Qlik content using iframes and need to display custom modals, add private labels to dialogs, or control messages when a user’s session disconnects.
You’ve embedded Qlik content into a portal and you want to keep the portal open for the duration of the user’s session.

Monitoring iframe content from Qlik uses enigma.js, a JavaScript library with access to Qlik Sense session state information.

Prerequisites

This code example uses JWTs to authorize users to Qlik Cloud. Ensure you have configured a JWT identity provider by following this article before proceeding. This article illustrates how to configure a JWT identity provider on Qlik Cloud and it includes sample code for generating a JWT. In addition, the example code in this tutorial utilizes backend code to ensure secure generation and signing of the token. You may choose to generate JWTs using a language a tech stack you prefer. The preceding referenced guide is written in NodeJS, and there is another example using Python to generate JSON web tokens. Learn more about using Python here.

Note: The backend code configured to generate the JWT uses a REST endpoint to GET request and return a JWT with a response payload like this: {"body":{"<token>"}}.

To use the example page in this tutorial, ensure you also have the following:

An existing application ID and sheet ID to embed.
A web integration configured which contains the location of the web page that will be embedding the Qlik Cloud application.
A content security policy entry with the frame-ancestors directive added for the location of the web page that will be embedding the Qlik Cloud application.
A method of generating and fetching the JWT from your backend.

Variable substitution and vocabulary

Throughout this tutorial, variables will be used to communicate value placement. The variable substitution format is <VARIABLE_NAME>. Here is a list of variables that appear in the sample code.

Variable	Description
`<TENANT>`	The domain for the tenant you are accessing. Equivalent to `tenant.region.qlikcloud.com`.
`<JWT_ENDPOINT>`	RESTful endpoint to retrieve JWT.
`<WEB_INTEGRATION_ID>`	The unique identifier of the web integration.
`<APP_ID>`	The unique identifier of the application.
`<SHEET_ID>`	The unique identifier of the sheet.
`<IDENTITY>`	An arbitrary string to establish a separate session state.

Note: The IDENTITY parameter can be used across iframes or other methods of embedding to tie and/or separate sessions accordingly. It is an optional parameter included in this example for illustrative purposes.

Pseudocode

The code in this sample ultimately does the following:

Handles logging into Qlik.
Fetches the CSRF token so that a websocket connection can be made to the engine.
Connects to the application leveraging enigma.js.
Establishes listeners on the websocket session closed and suspended and events.
Fetches the active theme of the application to style the embedded visualization consistently across user interfaces.
Renders the iframe.
A timer is set to automatically close the engine websocket session in 10 seconds.
The Engine WebSocket session is closed, which triggers the listener on the closed event, illustrating the catch.
The iframe is hidden and a custom message is displayed.

Sample code

The code example in this tutorial provides a basic, fully functional web page after successfully logging in to Qlik Cloud with JWT. It showcases a few capabilities in one example, providing a boilerplate you can modify. Here are some of the features:

Automatically hides the iframe and displays a message inline.
Catches session events, such as, displaying a custom modal dialog or redirecting to another web page.
Handles browser support for third-party cookies. Refer to this article for more information.

<html>

<head>
    <script src="https://unpkg.com/enigma.js/enigma.min.js"></script>
</head>

<body>

    <div id="main">
        <div id="message"></div>
        <iframe id='qlik_frame' style='border:none;width:100%;height:900px;'></iframe>
    </div>

    <script>

        //    CONFIGURATION

        const TENANT = '<TENANT>';
        const JWTENDPOINT = '<JWT_ENDPOINT>';
        const WEBINTEGRATIONID = '<WEB_INTEGRATION_ID>';
        const APPID = '<APP_ID>';
        const SHEETID = '<SHEET_ID>';
        const IDENTITY = '<IDENTITY>';

        //    MAIN

        (async function main() {
            const isLoggedIn = await qlikLogin();
            const qcsHeaders = await getQCSHeaders();
            const [session, enigmaApp] = await connectEnigma(qcsHeaders, APPID, IDENTITY);
            handleDisconnect(session);
            const theme = await getTheme(enigmaApp);
            renderSingleIframe('qlik_frame', APPID, SHEETID, theme, IDENTITY);
            const message = 'Session will be automatically closed in 10 seconds to showcase the handling.';
            document.getElementById('message').innerHTML = message;
            setTimeout(() => { // remove this after testing
                session.close();
            }, "10000")
        })();

        //    LOGIN

        async function qlikLogin() {
            const loggedIn = await checkLoggedIn();
            if (loggedIn.status !== 200) {
                const tokenRes = await (await getJWTToken(JWTENDPOINT)).json();
                const loginRes = await jwtLogin(tokenRes.body);
                if (loginRes.status != 200) {
                    const message = 'Something went wrong while logging in.';
                    alert(message);
                    throw new Error(message);
                }
                const recheckLoggedIn = await checkLoggedIn();
                if (recheckLoggedIn.status !== 200) {
                    const message = 'Third-party cookies are not enabled in your browser settings and/or browser mode.';
                    alert(message);
                    throw new Error(message);
                }
            }
            console.log('Logged in!');
            return true;
        }

        async function checkLoggedIn() {
            return await fetch(`https://${TENANT}/api/v1/users/me`, {
                mode: 'cors',
                credentials: 'include',
                headers: {
                    'qlik-web-integration-id': WEBINTEGRATIONID
                },
            })
        }

        //    Get the JWT and use it to obtain Qlik Cloud session cookie.

        async function getJWTToken(jwtEndpoint) {
            return await fetch(jwtEndpoint, {
                mode: 'cors',
                method: 'GET'
            })
        }

        async function jwtLogin(token) {
            const authHeader = `Bearer ${token}`;
            return await fetch(`https://${TENANT}/login/jwt-session?qlik-web-integration-id=${WEBINTEGRATIONID}`, {
                credentials: 'include',
                mode: 'cors',
                method: 'POST',
                headers: {
                    'Authorization': authHeader,
                    'qlik-web-integration-id': WEBINTEGRATIONID
                },
            })
        }

        async function getQCSHeaders() {
            const response = await fetch(`https://${TENANT}/api/v1/csrf-token`, {
                mode: 'cors',
                credentials: 'include',
                headers: {
                    'qlik-web-integration-id': WEBINTEGRATIONID
                },
            })

            const csrfToken = new Map(response.headers).get('qlik-csrf-token');
            return {
                'qlik-web-integration-id': WEBINTEGRATIONID,
                'qlik-csrf-token': csrfToken,
            };
        }


        //    ENIGMA ENGINE CONNECTION

        async function connectEnigma(qcsHeaders, appId, identity) {
            const [session, app] = await getEnigmaSessionAndApp(qcsHeaders, appId, identity);
            return [session, app];
        }

        async function getEnigmaSessionAndApp(headers, appId, identity) {
            const params = Object.keys(headers)
                .map((key) => `${key}=${headers[key]}`)
                .join('&');

            return (async () => {
                const schema = await (await fetch('https://unpkg.com/enigma.js@2.7.0/schemas/12.612.0.json')).json();

                try {
                    return await createEnigmaAppSession(schema, appId, identity, params);
                }
                catch {
                    // Handle race condition with new users who do not have permissions to access the application. The code makes another attempt after a 1.5 seconds.
                    const waitSecond = await new Promise(resolve => setTimeout(resolve, 1500));
                    try {
                        return await createEnigmaAppSession(schema, appId, identity, params);
                    }
                    catch (e) {
                        throw new Error(e);
                    }
                }
            })();
        }

        async function createEnigmaAppSession(schema, appId, identity, params) {
            const session = enigma.create({
                schema,
                url: `wss://${TENANT}/app/${appId}/identity/${identity}?${params}`
            });
            const enigmaGlobal = await session.open();
            const enigmaApp = await enigmaGlobal.openDoc(appId);
            return [session, enigmaApp];
        }

        //    BONUS! DYNAMICALLY FETCH THEME

        async function getTheme(enigmaApp) {
            const createAppProps = await enigmaApp.createSessionObject({
                qInfo: {
                    qId: "AppPropsList",
                    qType: "AppPropsList"
                },
                qAppObjectListDef: {
                    qType: "appprops",
                    qData: {
                        theme: "/theme"
                    }
                }
            });
            const appProps = await enigmaApp.getObject('AppPropsList');
            const appPropsLayout = await appProps.getLayout();
            const theme = appPropsLayout.qAppObjectList.qItems[0].qData.theme;
            return theme;
        }

        //    HANDLE ENGINE SESSION CLOSURE

        function handleDisconnect(session) {
            session.on('closed', () => {
                const message = '<Your text here> Due to inactivity or loss of connection, this session has ended.';
                document.getElementById('qlik_frame').style.display = "none";
                document.getElementById('message').innerHTML = message;
            });

            session.on('suspended', () => {
                const message = '<Your text here> Due to loss of connection, this session has been suspended.';
                document.getElementById('qlik_frame').style.display = "none";
                document.getElementById('message').innerHTML = message;
            });

            window.addEventListener('offline', () => {
                session.close();
            });
        }

        //    HELPER FUNCTION TO GENERATE IFRAME

        function renderSingleIframe(frameId, appId, sheetId, theme, identity) {
            const frameUrl = `https://${TENANT}/single/?appid=${appId}&sheet=${sheetId}&theme=${theme}&identity=${identity}&opt=ctxmenu,currsel`;
            document.getElementById(frameId).setAttribute('src', frameUrl);
        }


    </script>

</body>

</html>

Overview
Context
Prerequisites
Variable substitution and vocabulary
Pseudocode
Sample code