#lynx: cancelResourcePrefetch() static method

• This API is used to cancel resource preloading initiated by requestResourcePrefetch.

#Syntax

cancelResourcePrefetch(data: object, callback: (res: object) => void) : void;

#Parameters

#data

A collection that describes the details of all resources to be canceled for preloading, with its keys defined as follows:

• data: Type array, each item inside the array corresponds to a resource. The keys for each item are defined as follows:
  • uri: Type string, represents the CDN address of the resource.
  • type: Type string, represents the type of resource. The supported resource types are defined as follows:
    • video: Audio/video resources (preloading cancellation for image resources is currently not supported)
  • params: Custom control parameters for canceling preloading, the supported parameters are as follows:
    • preloadKey: Only for video type resources. Represents a unique key that identifies the resource. It is necessary to ensure that the preloadKey passed here is consistent with that used when calling requestResourcePrefetch. This is a required parameter.

#callback

The callback function that is called after the API execution is completed or fails. The structure of its return parameters is as follows:

• code: Type number, status code, which may take the following values:
  • 0: Success
  • 11001: Parameter error
• msg: Type string, a global error message
• details: Type array, where each detail represents the cancelation status details of a resource. The structure of each detail is as follows:
  • code: Type number, status code, which may take the following values:
    • 0: Success
    • 11001: Parameter error
  • msg: Type string, error message
  • uri: Type string, represents the CDN address of the resource.
  • type: Type string, represents the type of the resource, defined as follows:
    • video: Audio/video resources

#Return Value

None (undefined).

#Exceptions

• When there is a parameter error, code will return the 11001 error code, and the msg will contain detailed error information.

#Example

import { useEffect } from '@lynx-js/react';

function Page() {
  // We need to preload two videos.
  // First, prepare the resource parameters, assigning the necessary preloadKey to the videos.
  let resData = [
    {
      uri: 'https://zzzzz1.mp4',
      type: 'video',
      params: { preloadKey: 'zzzzz1' },
    },
    {
      uri: 'https://zzzzz2.mp4',
      type: 'video',
      params: { preloadKey: 'zzzzz2' },
    },
  ];

  useEffect(() => {
    // Call requestResourcePrefetch to initiate preloading
    lynx.requestResourcePrefetch?.(
      {
        data: resData,
      },
      (res) => {
        if (res.code == 0) {
          console.log('success!');
        } else {
          console.log('fail! ', res.msg);
        }
        console.log(
          'prefetch status of each resource:',
          JSON.stringify(res.details),
        );
      },
    );
  }, []);

  const handleTap = () => {
    // Trigger the cancellation of resource preloading on click
    // Call cancelResourcePrefetch to cancel the preloading
    lynx.cancelResourcePrefetch?.(
      {
        data: resData,
      },
      (res) => {
        if (res.code == 0) {
          console.log('success!');
        } else {
          console.log('fail! ', res.msg);
        }
        console.log(
          'cancel status of each resource:',
          JSON.stringify(res.details),
        );
      },
    );
  };

  return <view onTap={handleTap}>{/* ... */}</view>;
}

export default Page;

#Compatibility

LCD tables only load in the browser