Documentation – Technical Articles

Javascriptcpp: Monitor running programs with JavaScript via C++

Mon, 01 Jan 0001 00:00:00 +0000

How to monitor a running program

The following sample code shows how to monitor a running program. This code can be used to monitor the execution of Workbook‑related code. Simply use the SystemTimeInterruptMonitor class to create a monitoring object, use the LoadOptions.interruptMonitor(AbstractInterruptMonitor) function to add it to LoadOptions' running parameters, and then use the startMonitor function to set the expected interruption time (in milliseconds). If the running time of the monitored code exceeds the expected time, the program will be interrupted and an exception will be thrown.

Sample Code

<!DOCTYPE html>
<html>
    <head>
        <title>Aspose.Cells Interrupt Monitor Example</title>
    </head>
    <body>
        <h1>Interrupt Monitor Example</h1>
        <input type="file" id="fileInput" accept=".xls,.xlsx,.csv" />
        <button id="runExample">Run Example</button>
        <a id="downloadLink" style="display: none;">Download Result</a>
        <div id="result"></div>
    </body>

    <script src="aspose.cells.js.min.js"></script>
    <script type="text/javascript">
        const { Workbook, LoadOptions, SystemTimeInterruptMonitor, SaveFormat, 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');
            if (!fileInput.files.length) {
                document.getElementById('result').innerHTML = '<p style="color: red;">Please select an Excel file.</p>';
                return;
            }

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

            // Create interrupt monitor and load options
            const monitor = new SystemTimeInterruptMonitor(false);
            const lopts = new LoadOptions();
            lopts.interruptMonitor = monitor;
            monitor.startMonitor(1000); // time limit is 1 second

            // Load the workbook with the specified load options
            const wb = new Workbook(new Uint8Array(arrayBuffer), lopts);

            // If loading completed within time, start monitoring save
            monitor.startMonitor(1500); // time limit is 1.5 seconds
            const outputData = wb.save(SaveFormat.Xlsx);

            const blob = new Blob([outputData]);
            const downloadLink = document.getElementById('downloadLink');
            downloadLink.href = URL.createObjectURL(blob);
            downloadLink.download = 'result.xlsx';
            downloadLink.style.display = 'block';
            downloadLink.textContent = 'Download Result.xlsx';

            document.getElementById('result').innerHTML = '<p style="color: green;">Operation completed successfully! Click the download link to get the resulting file.</p>';
        });
    </script>
</html>

Javascriptcpp: Specifying Significant Digits to be Stored in Excel File with JavaScript via C++

Mon, 01 Jan 0001 00:00:00 +0000

Possible Usage Scenarios

By default, Aspose.Cells for JavaScript via C++ stores 17 significant digits of double values inside the Excel file, unlike MS‑Excel which stores only 15 significant digits. You can change the default behavior of Aspose.Cells from 17 significant digits to 15 significant digits using the CellsHelper.significantDigits property.

Specifying Significant Digits to be Stored in Excel File

The following sample code enforces Aspose.Cells to use 15 significant digits while storing double values inside the Excel file. Please check the output Excel file. Change its extension to .zip, unzip it, and you will see that only 15 significant digits are stored inside the Excel file. The following screenshot explains the effect of the CellsHelper.significantDigits property on the output Excel file.

Sample Code

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8" />
        <title>Aspose.Cells Example - Significant Digits</title>
    </head>
    <body>
        <h1>Significant Digits Example</h1>
        <p>This example sets CellsHelper.significantDigits to 15 and writes a double to cell A1.</p>
        <input type="file" id="fileInput" accept=".xls,.xlsx,.csv" />
        <button id="runExample">Run Example</button>
        <a id="downloadLink" style="display: none;">Download Result</a>
        <div id="result"></div>
    </body>

    <script src="aspose.cells.js.min.js"></script>
    <script type="text/javascript">
        const { Workbook, SaveFormat, CellsHelper } = 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');

            // If a file is provided, open it; otherwise create a new workbook (matches original Node behavior)
            let workbook;
            if (fileInput.files.length) {
                const file = fileInput.files[0];
                const arrayBuffer = await file.arrayBuffer();
                workbook = new Workbook(new Uint8Array(arrayBuffer));
            } else {
                workbook = new Workbook();
            }

            // By default, Aspose.Cells stores 17 significant digits, unlike MS‑Excel which stores only 15 significant digits
            CellsHelper.significantDigits = 15;

            // Access first worksheet
            const worksheet = workbook.worksheets.get(0);

            // Access cell A1
            const c = worksheet.cells.get("A1");

            // Put a double value; only 15 significant digits, as specified by CellsHelper.significantDigits above, will be stored
            c.value = 1234567890.123451711;

            // Saving the workbook
            const outputData = workbook.save(SaveFormat.Xlsx);
            const blob = new Blob([outputData]);
            const downloadLink = document.getElementById('downloadLink');
            downloadLink.href = URL.createObjectURL(blob);
            downloadLink.download = 'out_SignificantDigits.xlsx';
            downloadLink.style.display = 'block';
            downloadLink.textContent = 'Download Modified Excel File';

            document.getElementById('result').innerHTML = '<p style="color: green;">Workbook created/modified successfully! Click the download link to get the file.</p>';
        });
    </script>
</html>

Javascriptcpp: Comparison and Migration with JavaScript via C++

Mon, 01 Jan 0001 00:00:00 +0000

Comparison Between .NET and JavaScript via C++

When transitioning from Aspose.Cells for .NET to Aspose.Cells for JavaScript via C++, there are certain differences to consider in terms of library structure, syntax, and functionality. Below is a comparison to assist you in understanding these differences.

1. Initialization

In .NET, objects are often initialized using constructors. In JavaScript via C++, you will typically create instances using the new keyword, integrated into JavaScript syntax:

<!DOCTYPE html>
<html>
    <head>
        <title>Aspose.Cells Example</title>
    </head>
    <body>
        <h1>Aspose.Cells Workbook Creation Example</h1>
        <input type="file" id="fileInput" accept=".xls,.xlsx,.csv" />
        <button id="runExample">Create Workbook (or load selected file)</button>
        <a id="downloadLink" style="display: none;">Download Result</a>
        <div id="result"></div>
    </body>

    <script src="aspose.cells.js.min.js"></script>
    <script type="text/javascript">
        const { Workbook, SaveFormat, Worksheet, Cell, 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');
            let workbook;

            if (fileInput.files.length) {
                const file = fileInput.files[0];
                const arrayBuffer = await file.arrayBuffer();
                workbook = new Workbook(new Uint8Array(arrayBuffer));
                document.getElementById('result').innerHTML = '<p style="color: green;">Loaded workbook from selected file.</p>';
            } else {
                workbook = new Workbook();
                document.getElementById('result').innerHTML = '<p style="color: green;">Created a new empty workbook.</p>';
            }

            const outputData = workbook.save(SaveFormat.Xlsx);
            const blob = new Blob([outputData]);
            const downloadLink = document.getElementById('downloadLink');
            downloadLink.href = URL.createObjectURL(blob);
            downloadLink.download = 'output.xlsx';
            downloadLink.style.display = 'block';
            downloadLink.textContent = 'Download Excel File';
        });
    </script>
</html>

2. Accessing Worksheets

In .NET, you might see code like this to access a worksheet: