Handle sheets in iframes with enigma.js

Contributed by Daniel Pilla

Overview

In this tutorial, you are going to learn how to dynamically embed a sheet within an iframe, without having to hard code URLs and sheet IDs. This tutorial uses enigma.js to dynamically fetch, categorize, and sort a list of all sheets within an analytics application. With enigma.js, the developer can create custom drop-downs, navigation controls, provide sheet metadata type information, that is, whether the sheet is a “Base” or “Community” sheet, and more. If you are only looking to embed a single sheet, or the number of sheets is static and you are fine with hardcoding sheet IDs to buttons, then this approach is not necessary, however, this is frequently not the case. There are many scenarios where a custom UI is desired, but iframes are preferred due to their ease of use and portability.

Prerequisites

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

An existing application ID to embed.
A web integration configured that 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.

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`.
`<WEB_INTEGRATION_ID>`	The unique identifier of the web integration.
`<APP_ID>`	The unique identifier of the application.
`<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 example in this tutorial provides a basic, fully functional web page that executes the following sequence:

Handles logging into Qlik.
Fetches the CSRF token so that a websocket connection can be made to the Engine.
Connects to the application using enigma.js.
Establishes listeners on the websocket session closed and suspended events.
Fetches the active theme of the application (this is purely bonus code showing the power of the Engine).
Fetches the space ID of the application.
Fetches the space type that the application resides in.
Gets a list of all sheets within the application.
Categorizes each sheet by type: Base, Community, or Private, and sorts them by their type and subsequently by their rank (order displayed in the client.)
The sheets are logged to the console.
The iframe is rendered with the first sorted sheet in the sorted array.

The intent here is that you take the sheets array and build it into any type of navigation-oriented UI that you would like.

Sheet type and sorting

This code sample includes an algorithm to categorize and sort sheets. The matrices below document the criteria required for the categorization.

Applications in Managed Spaces:

	Published	Approved
Base	True	True
Community	True	False
Private	False	False

Applications in Shared Spaces:

	Published	Approved
Base	True	False
Private	False	False

The sorting is determined by the sheet’s rank property, which is sorted secondary to its sheet type. The sheet type sorting in this sample code is first sorted by Base, then Community, and finally Private.

Given this sample code’s categorization and sorting, the output resembles the following ordering (with the full sheet objects in JSON):

SheetType	SheetName
Base	Base Sheet 1
Base	Base Sheet 2
Community	Community Sheet 1
Community	Community Sheet 2
Private	Private Sheet 1
Private	Private Sheet 2

There are two custom attributes that this sample code adds to each sheet’s JSON object. They are:

Attribute	Definition
sheetType	”Base”, “Community”, or “Private”
sheetTypeEnum	Integer representation, where 1 == “Base”, 2 == “Community”, and 3 == “Private”

Sample code

The sample code showcases a few capabilities in one example, providing a boilerplate you can modify. Here are some of the features:

Catch 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 WEBINTEGRATIONID = '<WEB_INTEGRATION_ID>';
          const APPID = '<APP_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);
              const spaceId = (await getApp(APPID)).spaceId;
              const spaceType = await getSpaceType(spaceId);
              const sheets = await getSheetList(enigmaApp, spaceType);
              console.log(sheets);
              renderSingleIframe('qlik_frame', APPID, sheets[0].qInfo.qId, theme, IDENTITY);
          })();

          //    LOGIN

          async function qlikLogin() {
              const loggedIn = await fetch(`https://${TENANT}/api/v1/users/me`, {
                  mode: 'cors',
                  credentials: 'include',
                  headers: {
                      'qlik-web-integration-id': WEBINTEGRATIONID,
                  },
              })
              if (loggedIn.status !== 200) {
                  if (sessionStorage.getItem('tryQlikAuth') === null) {
                      sessionStorage.setItem('tryQlikAuth', 1);
                      window.location = `https://${TENANT}/login?qlik-web-integration-id=${WEBINTEGRATIONID}&returnto=${location.href}`;
                      return await new Promise(resolve => setTimeout(resolve, 10000)); // prevents further code execution
                  } else {
                      sessionStorage.removeItem('tryQlikAuth');
                      const message = 'Third-party cookies are not enabled in your browser settings and/or browser mode.';
                      alert(message);
                      throw new Error(message);
                  }
              }
              sessionStorage.removeItem('tryQlikAuth');
              console.log('Logged in!');
              return true;
          }

          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(appId, qcsHeaders, identity);
              return [session, app];
          }

          async function getEnigmaSessionAndApp(appId, headers, 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 {
                      // If the socket is closed immediately following the connection this
                      // could be due to an edge-case race condition where the newly created
                      // user does not yet have access to the app due to access control propagation.
                      // This bit of code will make 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];
          }

          //    HANDLE ENGINE SESSION CLOSURE

          function handleDisconnect(session) {
              session.on('closed', () => {
                  console.log('Due to inactivity or loss of connection, this session has ended.');
              });

              session.on('suspended', () => {
                  console.log('Due to loss of connection, this session has been suspended.');
              });

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

          //    GET QLIK APP (FOR SPACE ID)

          async function getApp(appId) {
              var url = new URL(`https://${TENANT}/api/v1/items?resourceType=app&resourceId=${appId}`);
              const response = await fetch(url, {
                  method: 'GET',
                  mode: 'cors',
                  credentials: 'include',
                  headers: {
                      'Content-Type': 'application/json',
                      'qlik-web-integration-id': WEBINTEGRATIONID,
                  },
              })
              responseJson = await response.json();
              return responseJson.data[0];
          }

          //    GET SPACE (FOR SPACE TYPE)

          async function getSpaceType(spaceId) {
              var url = new URL(`https://${TENANT}/api/v1/spaces/${spaceId}`);
              const response = await fetch(url, {
                  method: 'GET',
                  mode: 'cors',
                  credentials: 'include',
                  headers: {
                      'Content-Type': 'application/json',
                      'qlik-web-integration-id': WEBINTEGRATIONID,
                  },
              })
              responseJson = await response.json();
              return responseJson.type;
          }

          //    GET 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;
          }

          //    GET SHEETS (WITH TYPE ADDED, E.G., BASE, COMMUNITY, PRIVATE)

          async function getSheetList(app, spaceType) {
              var sheets = await app.getObjects(
                  {
                      "qOptions": {
                          "qTypes": [
                              "sheet"
                          ],
                          "qIncludeSessionObjects": false,
                          "qData": {}
                      }
                  }
              )
              sheetsIncludingType = [];
              for await (const sheet of sheets) {
                  var pushSheet = true;
                  const sheetObject = await app.getObject(sheet.qInfo.qId);
                  const sheetLayout = await sheetObject.getLayout();
                  var isManaged = spaceType === 'managed';
                  var sheetTypeEnum = 1;
                  var approved = sheet.qMeta.approved;
                  var published = sheet.qMeta.published;
                  const sheetTypeEnums = {
                      1: "Base",
                      2: "Community",
                      3: "Private"
                  };
                  if (!approved && !published) {
                      sheetTypeEnum = 3;
                  }
                  else if (!approved && published) {
                      if (isManaged) {
                          sheetTypeEnum = 2;
                      }
                  }
                  const sheetTypeObject = {
                      "sheetType": sheetTypeEnums[sheetTypeEnum],
                      "sheetTypeEnum": sheetTypeEnum
                  };
                  const mergedObject = {
                      ...sheetLayout,
                      ...sheetTypeObject
                  };
                  sheetsIncludingType.push(mergedObject)
              }
              sheetsIncludingType.sort((a, b) => (a.sheetTypeEnum - b.sheetTypeEnum || a.rank - b.rank))
              return sheetsIncludingType;
          }

          //    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
Prerequisites
Variable substitution and vocabulary
Pseudocode
Sheet type and sorting
Sample code