some html implementation

templates/export_to_csv.jinja2

@@ -0,0 +1,35 @@
+<button onclick="exportTableToCsv('result.csv')">Export to csv</button>
+
+<script type="application/javascript">
+    function downloadCsv(csv, filename) {
+        var csvFile = new Blob([csv], {"type": "text/csv"});
+
+        var downloadLink = document.createElement("a");
+        downloadLink.download = filename;
+        downloadLink.href = window.URL.createObjectURL(csvFile);
+        downloadLink.style.display = "none";
+
+        document.body.appendChild(downloadLink);
+        downloadLink.click();
+    }
+
+    function exportTableToCsv(filename) {
+        var table = document.getElementById("result");
+        var rows = table.getElementsByTagName("tr");
+
+        var csv = [];
+        for (var i = 0; i < rows.length; i++) {
+            if (rows[i].style.display === "none")
+                continue
+            var cols = rows[i].querySelectorAll("td, th");
+
+            var row = [];
+            for (var j = 0; j < cols.length; j++)
+                row.push(cols[j].innerText);
+
+            csv.push(row.join(","));
+        }
+
+        downloadCsv(csv.join("\n"), filename);
+    }
+</script>