1. Building Sites with Oracle Content Management
  2. Publishing and Managing Sites
  3. Improve Site Performance
  4. Above the Fold (ATF) Rendering

Above the Fold (ATF) Rendering

ATF rendering gives the appearance of a website loading faster than it actually does. The goal is to render first all the parts of a page that are visible and then, before the user scrolls down, render the rest of the page that is not initially visible.

A slot can have an "above the fold" designation, which displays an icon on the tab.

For a slot to be rendered in this new way, it must be marked with scs-atf, as follows: 

<div class="scs-slot scs-atf" id="headline"></div>

A component needs to notify the renderer when it is done rendering. Out-of-the-box components do this by default. A custom component can make additional calls and needs to do the following:

  1. Notify the renderer that it wants the renderer to wait until it is completed rendering.
  2. Notify the renderer when it has completed.

For #1, against the custom component's appinfo.json file, add in the following property: 

   "initialData": {
        . . .
        "customRenderComplete": true,
        . . .

For #2, in the component's render.js file, make sure that you let the renderer know when you're done by calling: 

 SitesSDK.setProperty('renderComplete', true);

If not all components in an ATF slot report back that they are done in a timely manner, then the renderer will wait for 2 seconds before continuing with the rest of the page. If you know this will not be long enough, you can extend the time by declaring the following global variable in a page template:

var SCSAtfPassTimeout = 3000;

Note:

The time is in milliseconds so this example set the timeout to 3 seconds.

An API provides diagnostic data for the ATF process. You can call the following method in the debug console, or you can access it from a page if needed:

SCSRenderAPI.getRenderMetrics();

For example:

{currentTime: 16243.400000000001, renderStartTime: 264.36, atfPassEndTime: 306.535, mainPassStartTime: 316.475, mainPassEndTime: 331.38500000000005, …}

1.   atfComponentCount:13

2.   atfPassEndTime:306.535

3.   completionCount:23

4.   completionRecords:Array(23)

1.   0:{atf: true, componentId: "a7afdd33-3fbb-4329-bc1b-6be60056a995", time: 280.065}

2.   1:{atf: true, componentId: "edfcfcb4-b0d3-422f-aa59-5c925bbbebee", time: 283.54}

3.   2:{atf: true, componentId: "c1c3aec8-e52f-406c-8c29-ab69c05877ed", time: 283.56000000000006}

4.   3:{atf: true, componentId: "b3a31dc6-62a1-44d9-9c80-bdb2c5bedaaa", time: 284.13000000000005}

5.   4:{atf: true, componentId: "c05aa1a2-c11c-4ef5-9051-4799c5bee24a", time: 284.15500000000003}

6.   5:{atf: true, componentId: "bafd4047-06ec-4739-9b23-9db74f573f30", time: 294.665}

7.   6:{atf: true, componentId: "e7d49528-0357-4b45-801e-b3a2716a086c", time: 297.995}

8.   7:{atf: true, componentId: "a5f33674-4022-4138-8cc5-fef00c02a557", time: 299.78000000000003}

9.   8:{atf: true, componentId: "ccfedc98-1dbd-440e-b867-5e683cea2ec5", time: 301.19500000000005}

10. 9:{atf: true, componentId: "d691bc44-fed9-474a-9806-2191f46a5e2e", time: 302.46}

11. 10:{atf: true, componentId: "cf613054-05d8-40dd-83a0-718760d7bc73", time: 303.79}

12. 11:{atf: true, componentId: "b4a6ef98-ffc8-48c7-987c-63346ee97bcc", time: 305.115}

13. 12:{atf: true, componentId: "de1fa2ce-66ba-419b-b517-2cb4a7601c3b", time: 306.535}

14. 13:{atf: false, componentId: "ba3f8ed4-31d4-4347-b6f0-f1019783a57c", time: 318.665}

15. 14:{atf: false, componentId: "ae8af486-76b3-47cd-9989-db4212eefebb", time: 320.45500000000004}

16. 15:{atf: false, componentId: "a48b5abb-49b2-4456-90bd-a3de998150c8", time: 320.48}

17. 16:{atf: false, componentId: "a9650e6d-7e7e-42a2-b758-58f2aeab18a2", time: 322.61500000000007}

18. 17:{atf: false, componentId: "aca9836a-f955-4aa7-8db2-fd3cf1189dea", time: 324.23500000000007}

19. 18:{atf: false, componentId: "e3d7941c-fbc7-4da9-963b-e3810b6467d4", time: 325.85}

20. 19:{atf: false, componentId: "eecde809-da54-4066-9326-73f9d9c35fe4", time: 327.315}

21. 20:{atf: false, componentId: "e8f4fb16-4e15-4570-b7de-304e99e449a7", time: 328.74}

22. 21:{atf: false, componentId: "a7baa06e-7f30-42c7-94f4-e171ab2edcd6", time: 330.09000000000003}

23. 22:{atf: false, componentId: "fd603b96-2beb-4e87-a54f-12d0e264cd0a", time: 331.38500000000005}

24. length:23

25. __proto__:Array(0)

5.   componentCount:23

6.   currentTime:16243.400000000001

7.   mainPassEndTime:331.38500000000005

8.   mainPassStartTime:316.475

9.   renderStartTime:264.36

10. __proto__:Object