D365FO Use of FileUpload control to Read CSV file

In Dynamics Ax implementation very often we get requirement to upload data using csv files. Although in Dynamics 365 for operations it can be easily done using data entities and data packages, in this blog we will see how can we use new FileUpload control and design classes to read, download files.

In  Dynamics 365 for operations  application runs on cloud and the client is in web , so Microsoft has introduce new process to read files using Azure blob. When we upload file, that file gets uploaded to Azure blob and we have to read that file from Azure blob to retrieve data.

Design classes:

There are two main types of classes that developers can work with for the file upload control:

• Upload strategy class – This class lets developers control various parameters that should be enforced for uploaded files, such as the types of files that a user can upload and the maximum size of a file. It also lets developers determine where and how the uploaded file should be stored. All upload strategy classes must inherit from the abstract FileUploadStrategyBase class. The framework provides a default upload strategy class named  FileUploadTemporaryStorageStrategy

• Upload result class – This class lets developers access the details of a file that was uploaded by a user, such as its name, content type, and upload status. It also lets developers open and delete the corresponding file. All upload result classes must inherit from the abstract FileUploadResultBase class. Default upload result class that is named FileUploadTemporaryStorageResult. This upload result class stores uploaded files to the temporary blob storage and provides a download URL.

  Below is X++ code to create dialog which uploads file in to blob storage and get temporary URL to retrieve data from the file.

    public Object dialog()
    {
        DialogGroup      dialogGroup;
        FormBuildControl formBuildControl;
        FileUploadBuild  dialogFileUpload;
        Set              enumSet = new Set(Types::Enum);
                
        ;
        
        dialog = super(); 		        
        dialogGroup = dialog.addGroup("File path");
        formBuildControl = dialog.formBuildDesign().control(dialogGroup.name());
        
        dialogFileUpload = formBuildControl.addControlEx(classstr(FileUpload), FileUploadName);
        dialogFileUpload.style(FileUploadStyle::MinimalWithFilename);
        dialogFileUpload.baseFileUploadStrategyClassName(classstr(FileUploadTemporaryStorageStrategy));
        dialogFileUpload.fileTypesAccepted(availableTypes);
        dialogFileUpload.fileNameLabel("@SYS308842");
    
        return dialog;
    }

You can see in the above code I used FileUploadBuild control and provided base class FileUploadTemporaryStorageStrategy to method baseFileUploadStrategyClassName which will be used to upload file to azure blob.

The FileTypesAccepted property of the file upload control lets you limit the types of files that users can upload

dialogFileUpload.fileTypesAccepted(availableTypes);

availableTypes is private Variable declared in classdeclaratoin which

private str                 availableTypes = ".csv";

In the class Declaration control names for OK and upload control

private const str OkButtonName = 'OkButton';

private const str FileUploadName = 'FileUpload';

Following methods is required to Enables or disables the dialog Ok button.

protected void setDialogOkButtonEnabled(DialogRunbase _dialog, boolean _isEnabled)
{
        FormControl okButtonControl = this.getFormControl(_dialog, OkButtonName);

        if (okButtonControl)
        {
            okButtonControl.enabled(_isEnabled);
        }
}
protected FormControl getFormControl(DialogRunbase _dialog, str _controlName)
{
        return _dialog.formRun().control(_dialog.formRun().controlId( _controlName));
}

Once the file has been uploaded to blob storage ok button needs to be enabled. Following method takes care of that by calling callback event handler to be notified when upload is complete.

protected void uploadCompleted()
 {
        FileUpload fileUpload = this.getFormControl(dialog, FileUploadName);
        fileUpload.notifyUploadCompleted -= eventhandler(this.UploadCompleted);
                
        textFile = fileUpload.fileName();

        this.setDialogOkButtonEnabled(dialog, true);
  }


/// Disables the dialog Ok button until the file upload is complete.
    
    public void dialogPostRun(DialogRunbase _dialog)
    {
        FileUpload fileUpload = this.getFormControl(_dialog, FileUploadName);
        fileUpload.notifyUploadCompleted += eventhandler(this.uploadCompleted);
        this.setDialogOkButtonEnabled(_dialog, false);
    }
  
 

void processCSVFile()
    {
        #File
        container               currentLine;
        int                     totalOfLines;
        CommaTextStreamIo       localStream;
        Num                     number;
            
       
        FileUpload fileUploadControl = this.getFormControl(dialog, FileUploadName);
        
        FileUploadTemporaryStorageResult fileUploadResult = fileUploadControl.getFileUploadResult();
        
        if (fileUploadResult != null && fileUploadResult.getUploadStatus())
        {
            textFile = fileUploadResult.getDownloadUrl();
        }
        
        localStream = CommaTextStreamIo::constructForRead(File::UseFileFromURL(textFile));
       
          
        if (localStream.status() != IO_Status::Ok)
        {
            throw error(strfmt('Is not possible to open the file. Error %1',enum2str(localStream.status())));
        }
    
        localStream.inFieldDelimiter("\,");
        localStream.inRecordDelimiter("\n");
    
        currentLine = localStream.read();
        fileLineNumber++;
    
        if(conlen(currentLine) == 1)
        {
            throw error('Is not possible to import the file, incorrect format');
        }
    
            
        currentLine = localStream.read();
        fileLineNumber++;
    
        while(currentLine)
        {
            number = conPeek(currentLine,1);

            info(strFmt("Number : %1",number));

             
            currentLine = localStream.read();
                
        }
    
 
    }