Android Media & History

A media message must upload its local file to a remote location available to other devices. The SDK owns message state; your app performs object-storage upload and authorization.

Send an image

WKImageContent image = new WKImageContent(localPath);
image.width = width;
image.height = height;

WKChannel channel = new WKChannel("team-1", WKChannelType.GROUP);
WKIM.getInstance().getMsgManager().send(image, channel);

Configure attachment upload before sending media:

msgManager.addOnUploadAttachListener((message, result) -> {
    if (!(message.baseContentMsgModel instanceof WKImageContent)) {
        result.onUploadResult(false, message.baseContentMsgModel);
        return;
    }

    WKImageContent content =
        (WKImageContent) message.baseContentMsgModel;
    objectStorage.upload(content.localPath, (url, error) -> {
        if (error == null) {
            content.url = url;
            result.onUploadResult(true, content);
        } else {
            result.onUploadResult(false, content);
        }
    });
});

Upload credentials should be short lived and limited by path, size, and file type. Never treat localPath as a URL the receiving device can access.

Connect remote history

getOrSyncHistoryMessages reads the local database first. It invokes the channel synchronization listener when the local range is incomplete:

msgManager.addOnSyncChannelMsgListener((
    channelID,
    channelType,
    startMessageSeq,
    endMessageSeq,
    limit,
    pullMode,
    callback
) -> historyApi.fetch(
    channelID,
    channelType,
    startMessageSeq,
    endMessageSeq,
    limit,
    pullMode,
    callback::onBack
));

The application API converts its response to WKSyncChannelMsg, with a WKSyncRecent list in messages. Complete with an empty result when there is no data; never leave the screen waiting forever.

Common problems

• Image remains sending: ensure upload always calls onUploadResult and writes content.url on success.
• Other devices cannot display the image: make sure the receiver can authorize and download the URL; it cannot use the sender's sandbox path.
• Duplicate history: merge by channel and messageSeq, not array position.
• History never finishes: time out the application request and end UI loading on success, empty data, and failure.