Custom Download Function for GridJs

How to implement custom download function for GridJs

GridJs provides a flexible download mechanism that allows you to customize the file download behavior. You can set a custom download function to handle file downloads according to your requirements.

Set Custom Download Function

GridJs provides the setFileDownloadCallFunction method to set a custom download function. When users click the download button, this function will be called with specific parameters.

Basic Usage

// Define your custom download function
function customDownloadHandler(toFileName, outputType, saveMode) {
    console.log('File Name:', toFileName);
    console.log('Output Type:', outputType);
    console.log('Save Mode:', saveMode);
    
    // Implement your custom download logic here
    // For example: upload to cloud storage, save to custom location, etc.
}

// Set the custom download function
xs.setFileDownloadCallFunction(customDownloadHandler);

Function Parameters

The custom download function receives three parameters:

1. toFileName

Type: String
Description: The name of the file to be downloaded
Example: "myfile.xlsx", "report.pdf"

2. outputType

Type: String
Description: The output file format type
Possible Values:
- Original - Keep the original file format
- XLSX - Export as Excel format
- PDF - Export as PDF format
- HTML - Export as HTML format

3. saveMode

Type: String
Description: The save destination mode
Possible Values:
- Device - Download to local device (default)
- GoogleDrive - Save to Google Drive
- Dropbox - Save to Dropbox

Download Scenarios

GridJs supports multiple download scenarios based on different user actions:

1. Download as Different Formats

function customDownloadHandler(toFileName, outputType, saveMode) {
    switch(outputType) {
        case 'Original':
            // Handle original format download
            downloadAsOriginal(toFileName);
            break;
        case 'XLSX':
            // Handle Excel format download
            downloadAsExcel(toFileName);
            break;
        case 'PDF':
            // Handle PDF format download
            downloadAsPDF(toFileName);
            break;
        case 'HTML':
            // Handle HTML format download
            downloadAsHTML(toFileName);
            break;
    }
}

xs.setFileDownloadCallFunction(customDownloadHandler);

2. Save to Cloud Storage

function customDownloadHandler(toFileName, outputType, saveMode) {
    if (saveMode === 'GoogleDrive') {
        // Implement Google Drive upload logic
        uploadToGoogleDrive(toFileName, outputType);
    } else if (saveMode === 'Dropbox') {
        // Implement Dropbox upload logic
        uploadToDropbox(toFileName, outputType);
    } else {
        // Default: download to device
        downloadToDevice(toFileName, outputType);
    }
}

xs.setFileDownloadCallFunction(customDownloadHandler);

Notes

Function Registration: Make sure to call setFileDownloadCallFunction before users interact with the download functionality.
Error Handling: Always implement proper error handling in your custom download function to provide feedback to users.
Async Operations: If your download logic involves asynchronous operations (like API calls), make sure to handle promises appropriately.
File Name Extension: When the output type is not “Original”, the file extension will be automatically adjusted to match the output type (e.g., .xlsx, .pdf, .html).
Default Behavior: If you don’t set a custom download function, GridJs will use its default download behavior.