如何使用Javascript将数据从网站导出到csv文件？

Question

I saw this code from a website and apparently it works on other people even for my friend but not for me. I am using Nodejs and express. Am i doing it wrongly or did i miss out any important parts? After the button was clicked, that was no pop out of the file directory or anything and there is no error to be seen as well.

This are the codes from the script.

<script>
        function downloadCSV(csv, filename) {
            var csvFile;
            var downloadLink;
            //var charset = "UTF-8";

            // CSV File
            csvFile = new Blob([csv], {type: "text/csv"});

            // download link
            downloadLink = document.createElement("a");

            // file name
            downloadLink.download = filename;

            // create link to file
            downloadLink.href = window.URL.createObjectURL(csvFile);

            // hide download link
            downloadLink.style.display = "";

            // add link to DOM
            document.body.appendChild(downloadLink);

            // click download link
            downloadLink.click();
        }

        function exportData(html,filename) {
            var csv = [];
            var rows = document.querySelectorAll("table tr");

            for (var i=0; i<rows.length; i++) {
                var rows = [], cols = rows[i].querySelectorAll("td, th");

                for (var j=0; j<cols.length; j++) {
                    if (j == 7) {
                        row.push("'" + cols[j].innerText + "'");
                    } 
                    else if (j == 2){
                        row.push("'" + cols[j].innerText + "'");
                    } 
                    else {
                        row.push(cols[j].innerText);
                    }
                }

                csv.push(row.join(","));
            }

            // download csv file
            downloadCSV(csv.join("\n"), filename);

        }
    </script>

This are the codes from the design part.

  <button type="button" class="btn btn-primary" id="exportBtn" onclick="exportData(null,'scrapedData.csv')">导出</button>

Answer 1

This minimal example is working

  function downloadCSV(csv, filename) { var csvFile; var downloadLink; // CSV File csvFile = new Blob([csv], {type: "text/csv"}); // download link downloadLink = document.createElement("a"); // file name downloadLink.download = filename; // create link to file downloadLink.href = window.URL.createObjectURL(csvFile); // hide download link downloadLink.style.display = ""; // add link to DOM document.body.appendChild(downloadLink); // click download link downloadLink.click(); } function exportData(html,filename) { var csv = []; csv.push('a'); csv.push('b'); csv.push('c'); csv.push('d'); csv.push('e'); // download csv file downloadCSV(csv.join("\\n"), filename); } 

 <button onClick="exportData(null, 'testCSV.csv')">download</button>