1<table class="fixed" border="0">
2    <col width="1000px" /><col width="500px" />
3    <tr><td>
4        <h2>ESP32 File Server</h2>
5    </td><td>
6        <table border="0">
7            <tr>
8                <td>
9                    <label for="newfile">Upload a file</label>
10                </td>
11                <td colspan="2">
12                    <input id="newfile" type="file" onchange="setpath()" style="width:100%;">
13                </td>
14            </tr>
15            <tr>
16                <td>
17                    <label for="filepath">Set path on server</label>
18                </td>
19                <td>
20                    <input id="filepath" type="text" style="width:100%;">
21                </td>
22                <td>
23                    <button id="upload" type="button" onclick="upload()">Upload</button>
24                </td>
25            </tr>
26        </table>
27    </td></tr>
28</table>
29<script>
30function setpath() {
31    var default_path = document.getElementById("newfile").files[0].name;
32    document.getElementById("filepath").value = default_path;
33}
34function upload() {
35    var filePath = document.getElementById("filepath").value;
36    var upload_path = "/upload/" + filePath;
37    var fileInput = document.getElementById("newfile").files;
38
39    /* Max size of an individual file. Make sure this
40     * value is same as that set in file_server.c */
41    var MAX_FILE_SIZE = 200*1024;
42    var MAX_FILE_SIZE_STR = "200KB";
43
44    if (fileInput.length == 0) {
45        alert("No file selected!");
46    } else if (filePath.length == 0) {
47        alert("File path on server is not set!");
48    } else if (filePath.indexOf(' ') >= 0) {
49        alert("File path on server cannot have spaces!");
50    } else if (filePath[filePath.length-1] == '/') {
51        alert("File name not specified after path!");
52    } else if (fileInput[0].size > 200*1024) {
53        alert("File size must be less than 200KB!");
54    } else {
55        document.getElementById("newfile").disabled = true;
56        document.getElementById("filepath").disabled = true;
57        document.getElementById("upload").disabled = true;
58
59        var file = fileInput[0];
60        var xhttp = new XMLHttpRequest();
61        xhttp.onreadystatechange = function() {
62            if (xhttp.readyState == 4) {
63                if (xhttp.status == 200) {
64                    document.open();
65                    document.write(xhttp.responseText);
66                    document.close();
67                } else if (xhttp.status == 0) {
68                    alert("Server closed the connection abruptly!");
69                    location.reload()
70                } else {
71                    alert(xhttp.status + " Error!\n" + xhttp.responseText);
72                    location.reload()
73                }
74            }
75        };
76        xhttp.open("POST", upload_path, true);
77        xhttp.send(file);
78    }
79}
80</script>
81