jquery validate if input file is not empty

AatishKumar
June 13, 2023
180 views
2 votes
3 Answers

I’m trying to validate the input file field if it is empty or not but its not working.
I’m having multiple form tags on my page so i need to check if the current submitted form’s file input is empty or not.

$(document).ready(function() {
    $("form").on('submit', function(e) {
        e.preventDefault();
        var fileInput = $(this).find('input[type="file"]');
        console.log(fileInput);
        if (fileInput.length === 0) {
            alert("Please select a file to upload.");
            return;
        }
    });
});

html

<div id="content">
   <div style="padding:1% 0">
        <table>
            <thead>
                <tr>
                    <td>Type</td>
                    <td>Select Files</td>
                </tr>
            </thead>
            <tbody>
                <tr>
                    <form method="post" enctype="multipart/form-data">
                    <input type="hidden" name="recID" value="">
                    <td>File 1</td>
                    <td><input type="file" name="file1" class="fileinput"></td>
                    <td><input type="submit" name="submit" value="Upload"></td>
                    </form>
                </tr>
                <tr>
                    <form method="post" enctype="multipart/form-data">
                    <input type="hidden" name="recID" value="">
                    <td>File 2</td>
                    <td><input type="file" name="file2" class="fileinput"></td>
                    <td><input type="submit" name="submit" value="Upload"></td>
                    </form>
                </tr>
                <tr>
                    <form method="post" enctype="multipart/form-data">
                    <input type="hidden" name="recID" value="">
                    <td>File 3</td>
                    <td><input type="file" name="file3" class="fileinput"></td>
                    <td><input type="submit" name="submit" value="Upload"></td>
                    </form>
                </tr>
                <tr>
                    <form method="post" enctype="multipart/form-data">
                    <input type="hidden" name="recID" value="">
                    <td>File 4</td>
                    <td><input type="file" name="file4" class="fileinput"></td>
                    <td><input type="submit" name="submit" value="Upload"></td>
                    </form>
                </tr>
                <tr></tr>
                <tr><td colspan="3"><a href="back.php"><button type="button">Go Back</button></a></td></tr>
            </tbody>
        </table>
</div>

I tried multiple time by all methods but not working.

Answers

- Ali
- June 10, 2023 at 6:14 pm
- 0 votes
0
Make sure that you are not used form inside another form. it will conflict when place a form inside another form.

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Value for files can be accessed under .files. You need to rectify the condition to check the length as below,

$(document).ready(function() {
  $("form").on('submit', function(e) {
    e.preventDefault();
    var fileInput = $(this).find('input[type="file"]');
    if (typeof(fileInput[0]) !== "undefined" && fileInput[0].files.length === 0) {
      alert("Please select a file to upload.");
      return;
    }
  });
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<form>
  <input type="file" id="file-upload" />
  <input type="submit" />
</form>
<form>
  <input type="file" id="file-upload1" />
  <input type="submit" />
</form>
<form>
  <input type="text" />
  <input type="submit" />
</form>

Update:

In case of multiple forms where input type file is missing, it will throw undefined error. To resolve that add a check typeof(fileInput[0]) !== "undefined" in the condition.

Check the value as below

if (fileInput.val() === '') {
    alert("Please select a file to upload.");
    return;
 }

@Updated as per the modified question. You need to restructure HTML table

$(document).ready(function() {
  $("form").on('submit', function(e) {
    e.preventDefault();
    var fileInput = $(this).find('input[type="file"]');
    if (fileInput.val() === '') {
      alert("Please select a file to upload.");
      return;
    }
  });
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Select Files</th>
      <th>Action</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>File 1</td>
      <td>
        <form method="post" enctype="multipart/form-data" id="form1">
          <input type="hidden" name="recID" value="">
          <input type="file" name="file1" class="fileinput">
        </form>
      </td>
      <td>
        <input type="submit" name="submit" value="Upload" form="form1">
      </td>
    </tr>
    <tr>
      <td>File 2</td>
      <td>
        <form method="post" enctype="multipart/form-data" id="form2">
          <input type="hidden" name="recID" value="">
          <input type="file" name="file2" class="fileinput">
        </form>
      </td>
      <td>
        <input type="submit" name="submit" value="Upload" form="form2">
      </td>
    </tr>
    <tr>
      <td>File 3</td>
      <td>
        <form method="post" enctype="multipart/form-data" id="form3">
          <input type="hidden" name="recID" value="">
          <input type="file" name="file3" class="fileinput">
        </form>
      </td>
      <td>
        <input type="submit" name="submit" value="Upload" form="form3">
      </td>
    </tr>
    <tr>
      <td>File 4</td>
      <td>
        <form method="post" enctype="multipart/form-data" id="form4">
          <input type="hidden" name="recID" value="">
          <input type="file" name="file4" class="fileinput">
        </form>
      </td>
      <td>
        <input type="submit" name="submit" value="Upload" form="form4">
      </td>
    </tr>
    <tr>
      <td colspan="3">
        <a href="back.php">
          <button type="button">Go Back</button>
        </a>
      </td>
    </tr>
  </tbody>
</table>

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