Trim Leading Blank Rows and Columns while exporting spreadsheets to CSV format with JavaScript via C++

Possible Usage Scenarios

Sometimes, your Excel or CSV file has leading blank columns or rows. For example, consider this line:

 ,,,data1,data2

Here the first three cells (or columns) are blank. When you open such a CSV file in Microsoft Excel, it discards these leading blank rows and columns.

By default, Aspose.Cells for JavaScript via C++ does not discard leading blank columns and rows on saving, but if you want to remove them just as Microsoft Excel does, set Aspose.Cells' TxtSaveOptions.trimLeadingBlankRowAndColumn property to true. All the leading blank rows and columns will then be discarded on saving.

Prior to the release of Aspose.Cells for JavaScript via C++ 20.4, the default value of TxtSaveOptions.trimLeadingBlankRowAndColumn was false. Since the 20.4 release, the default value of TxtSaveOptions.trimLeadingBlankRowAndColumn is true.

Trim Leading Blank Rows and Columns while exporting spreadsheets to CSV format

The following sample code loads the source Excel file (sampleTrimBlankColumns.xlsx) that has two leading blank columns. It first saves the Excel file in CSV format without any changes, then sets TxtSaveOptions.trimLeadingBlankRowAndColumn to true and saves it again. The screenshot shows the source Excel file, the output CSV file without trimming, and the output CSV file with trimming.

Sample Code

<!DOCTYPE html>
<html>
    <head>
        <title>Aspose.Cells Example - Trim Blank Columns</title>
    </head>
    <body>
        <h1>Trim Blank Columns Example</h1>
        <input type="file" id="fileInput" accept=".xls,.xlsx,.csv" />
        <button id="runExample">Run Example</button>
        <a id="downloadLink1" style="display: none;">Download Result 1</a>
        <a id="downloadLink2" style="display: none; margin-left: 10px;">Download Result 2</a>
        <div id="result"></div>
    </body>

    <script src="aspose.cells.js.min.js"></script>
    <script type="text/javascript">
        const { Workbook, SaveFormat, TxtSaveOptions, Utils } = AsposeCells;
        
        AsposeCells.onReady({
            license: "/lic/aspose.cells.enc",
            fontPath: "/fonts/",
            fontList: [
                "arial.ttf",
                "NotoSansSC-Regular.ttf"
            ]
        }).then(() => {
            console.log("Aspose.Cells initialized");
        });

        document.getElementById('runExample').addEventListener('click', async () => {
            const fileInput = document.getElementById('fileInput');
            const resultDiv = document.getElementById('result');
            if (!fileInput.files.length) {
                resultDiv.innerHTML = '<p style="color: red;">Please select an Excel file.</p>';
                return;
            }

            const file = fileInput.files[0];
            const arrayBuffer = await file.arrayBuffer();

            // Load source workbook
            const wb = new Workbook(new Uint8Array(arrayBuffer));

            // Save in CSV format (without trimming)
            const outputData1 = wb.save(SaveFormat.Csv);
            const blob1 = new Blob([outputData1]);
            const downloadLink1 = document.getElementById('downloadLink1');
            downloadLink1.href = URL.createObjectURL(blob1);
            downloadLink1.download = 'outputWithoutTrimBlankColumns.csv';
            downloadLink1.style.display = 'inline-block';
            downloadLink1.textContent = 'Download CSV Without Trimming';

            // Now save again with TrimLeadingBlankRowAndColumn set to true
            const opts = new TxtSaveOptions();
            opts.trimLeadingBlankRowAndColumn = true;

            // Save in CSV format (with trimming)
            const outputData2 = wb.save(opts);
            const blob2 = new Blob([outputData2]);
            const downloadLink2 = document.getElementById('downloadLink2');
            downloadLink2.href = URL.createObjectURL(blob2);
            downloadLink2.download = 'outputTrimBlankColumns.csv';
            downloadLink2.style.display = 'inline-block';
            downloadLink2.textContent = 'Download CSV With Trimmed Blank Columns';

            resultDiv.innerHTML = '<p style="color: green;">Files generated. Use the links above to download the CSVs.</p>';
        });
    </script>
</html>

Keep Separators for Blank Rows while exporting spreadsheets to CSV format with JavaScript via C++