Google Drive - Nested operations for undo/redo

Question

If I have code like follows

model.beginCompoundOperation();

model.beginCompoundOperation()
someModelChanges();
model.endCompoundOperation();

model.beginCompoundOperation()
someMoreModelChanges();
model.endCompoundOperation();

model.endCompoundOperation()

When I call undo, will it group someModelChanges, and someMoreModelChanges together? I would like both to be undone as a batch operation. Thanks!

Answer 1

I put together a test page for this and it has the behavior you want and I would expect. Have fun with the realtime API!

var clientId = "<<<REPLACE WITH YOUR CLIENT ID>>>";
var REALTIME_MIMETYPE = 'application/vnd.google-apps.drive-sdk';

// Everything interesting is at the bottom in the onDocLoaded function.

function createRealtimeFile(title, description, callback)
{
    console.log('Creating Drive Document');
    gapi.client.drive.files.insert({
        'resource':
        {
            'mimeType': REALTIME_MIMETYPE,
            'title': title,
            'description': description
        }
    }).execute(function (docInfo)
    {
        callback(docInfo, /*newDoc*/true);
    });
}

function openRealtimeFile(title, callback)
{
    gapi.client.load('drive', 'v2', function ()
    {
        gapi.client.drive.files.list(
        {
            'q': 'title='+"'"+title+"' and 'me' in owners and trashed=false"
        }).execute(function (results)
        {
            if (!results.items)
            {
                createRealtimeFile(title, /*DocDescription*/"", callback);
            }
            else
            {
                callback(results.items[0], /*newDoc*/false);
            }
        });
    });
}

function onPageLoad()
{
    var GScope =
    {
        Drive: 'https://www.googleapis.com/auth/drive.file'
    };

    gapi.load('auth:client,drive-realtime,drive-share', function()
    {
        var handleAuthResult = function(authResult)
        {
            console.log('Requesting Drive Document');

            openRealtimeFile("TESTDOC__", function (docInfo, newDoc)
            {
                if (docInfo && docInfo.id)
                {
                    gapi.drive.realtime.load(docInfo.id, onDocLoaded, onDocInitialized, onDocLoadError);
                }
                else
                {
                    console.log('Unable to find realtime doc');
                    debugger;
                }
            });
        };

        gapi.auth.authorize(
        {
            client_id: clientId,
            scope: [ GScope.Drive ],
            immediate: false
        }, handleAuthResult);
    });
}

function onDocInitialized(model)
{
    console.log('Drive Document Initialized');

    var docRoot = model.createMap();

    model.getRoot().set('docRoot', docRoot);
}

function onDocLoaded(doc)
{
    var docModel = doc.getModel();
    var docRoot = docModel.getRoot();

    console.log('Drive Document Loaded');


    // If the loaded document has already been used to test, delete any previous data.
    if (docRoot.has('testMap'))
    {
        docRoot.delete('testMap');
    }

    // Setup the new test data
    docRoot.set('testMap', docModel.createMap());

    var testMap = docRoot.get('testMap');
    console.assert(testMap, 'Test map required');

    var testString = docModel.createString();
    testMap.set('testString', testString);

    console.assert(testString.getText() === '');



    docModel.beginCompoundOperation();

    docModel.beginCompoundOperation();
    testString.append('AAA');
    docModel.endCompoundOperation();

    docModel.beginCompoundOperation();
    testString.append('BBB');
    docModel.endCompoundOperation();

    docModel.endCompoundOperation();


    console.assert(testString.getText() === 'AAABBB');

    docModel.undo();

    console.assert(testString.getText() === '');

    debugger;
}

function onDocLoadError(e)
{
    console.log('Doc Load Error: ', e);
    findAndLoadDoc();
}