Document Saving

function Dynamsoft_OnReady() { 
    DWTObject = Dynamsoft.DWT.GetWebTwain('dwtcontrolContainer'); // Get the Dynamic Web TWAIN object that is embedded in the div with id 'dwtcontrolContainer' 
    if (DWTObject) { 
        DWTObject.IfShowUI = false;
        DWTObject.IfAutoDiscardBlankpages = false;
        DWTObject.RegisterEvent('OnPostAllTransfers', CheckBlankPage); //Register the OnPostAllTransfers event that will be called after all scanning is complete 
    } 
}

function AcquireImage() {
    if (DWTObject) {
        DWTObject.SelectSource(function () {					
            var OnAcquireImageSuccess = function () {
                DWTObject.CloseSource();
            };
            
            var OnAcquireImageFailure = function (ec, es) {
                DWTObject.CloseSource();
                alert(es);
            };

            DWTObject.OpenSource();
            DWTObject.IfDisableSourceAfterAcquire = false;	// Scanner source will be disabled/closed automatically after the scan. 
            DWTObject.AcquireImage(OnAcquireImageSuccess, OnAcquireImageFailure);
        }, function () {
            console.log('SelectSource failed!');
        });
    }
}

function OnSuccess() {
    console.log('successful');
}

function OnFailure(errorCode, errorString) {
    alert(errorString);
}

async function CheckBlankPage() { //Function for checking a blank page, called when OnPostAllTransfers is triggered
    if (DWTObject) { //Ensure there is a DWTObject
        var startindex = 0; // Assume it starts from the first page in the buffer.
        for (var i = 0; i < DWTObject.HowManyImagesInBuffer; i++) { //Go through each image in the buffer.
            if (await DWTObject.IsBlankImageAsync(i)) {
                DWTObject.RemoveImage(i); // remove the blank page from the buffer.
                if (i != 0) {
                    var imageRecord = [];
                    i--; //decrement i for the removed image
                    var selectedCount = i - startindex + 1;

                    for (var j = 0; j < selectedCount; j++) { //loop to select all images from previous blank to current
                        imageRecord.push(j + startindex);
                    }

                    if (selectedCount > 0) { //save images as long as there are some in the selection
                        DWTObject.SelectImages(imageRecord);
                        DWTObject.IfShowFileDialog = true;
                        DWTObject.SaveSelectedImagesAsMultiPagePDF("C:\\....", OnSuccess, OnFailure); //PLEASE CHANGE THIS FILE PATH (The first parameter)
                    }

                    startindex = i + 1; //set the start index for next search 1 higher than current page
                }
            } else if (i == DWTObject.HowManyImagesInBuffer - 1) { //the last few images are not blank
                var selectedCount = i - startindex + 1; // set how many images are selected
                var imageRecord = [];

                for (var j = 0; j < selectedCount; j++) { //loop to select all images from previous blank to current
                    imageRecord.push(j + startindex);
                }

                if (selectedCount > 0) { //save images as long as there are some in the selection
                    DWTObject.SelectImages(imageRecord);
                    DWTObject.IfShowFileDialog = true;
                    DWTObject.SaveSelectedImagesAsMultiPagePDF("C:\\...", OnSuccess, OnFailure); //PLEASE CHANGE THIS FILE PATH (The first parameter)
                }
            }
        }
    }
}

var isBlank = await DWTObject.IsBlankImageAsync(i, { minBlockHeight: 10, maxBlockHeight: 40 });