My goal is to first validate the upload file is an image and if it is an image I will display it. I get the codes from Validation Code and Image Code.

At first I was able to display image. However, when I combined display image code with validation code, I did not able to get both validation and display worked.

Can anyone please help me? Below are my codes. Thanks in advance! :)

<input type="file" name="dataFile" id="fileChooser" onchange="readURL(this);" />





<SCRIPT type="text/javascript">

var _validFileExtensions = [".jpg", ".jpeg", ".bmp", ".gif", ".png"];

     function readURL(input) {

         var arrInputs = document.getElementById("fileChooser").value;
            for (var i = 0; i < arrInputs.length; i++) {
                var oInput = arrInputs[i];
                if (oInput.type == "file") {
                    var sFileName = oInput.value;
                if (sFileName.length > 0) {
                    var blnValid = false;
                    for (var j = 0; j < _validFileExtensions.length; j++) {
                        var sCurExtension = _validFileExtensions[j];
                        if (sFileName.substr(sFileName.length - sCurExtension.length, sCurExtension.length).toLowerCase() == sCurExtension.toLowerCase()) {
                            blnValid = true;

                            if (input.files && input.files[0])  {
                                var reader = new FileReader();

                                reader.onload = function (e) {
                                    $('#blah').attr('src', e.target.result)
                                };

                                reader.readAsDataURL(input.files[0]);
                            }


                            break;
                        }
                    }

                    if (!blnValid) {
                        alert("Sorry, " + sFileName + " is invalid, allowed extensions are: " + _validFileExtensions.join(", "));
                        return false;
                    }
                }
            }
        }

        return true;





    }

My goal is to first validate the upload file is an image and if it is an image I will display it. I get the codes from Validation Code and Image Code.

At first I was able to display image. However, when I combined display image code with validation code, I did not able to get both validation and display worked.

Can anyone please help me? Below are my codes. Thanks in advance! :)

<input type="file" name="dataFile" id="fileChooser" onchange="readURL(this);" />





<SCRIPT type="text/javascript">

var _validFileExtensions = [".jpg", ".jpeg", ".bmp", ".gif", ".png"];

     function readURL(input) {

         var arrInputs = document.getElementById("fileChooser").value;
            for (var i = 0; i < arrInputs.length; i++) {
                var oInput = arrInputs[i];
                if (oInput.type == "file") {
                    var sFileName = oInput.value;
                if (sFileName.length > 0) {
                    var blnValid = false;
                    for (var j = 0; j < _validFileExtensions.length; j++) {
                        var sCurExtension = _validFileExtensions[j];
                        if (sFileName.substr(sFileName.length - sCurExtension.length, sCurExtension.length).toLowerCase() == sCurExtension.toLowerCase()) {
                            blnValid = true;

                            if (input.files && input.files[0])  {
                                var reader = new FileReader();

                                reader.onload = function (e) {
                                    $('#blah').attr('src', e.target.result)
                                };

                                reader.readAsDataURL(input.files[0]);
                            }


                            break;
                        }
                    }

                    if (!blnValid) {
                        alert("Sorry, " + sFileName + " is invalid, allowed extensions are: " + _validFileExtensions.join(", "));
                        return false;
                    }
                }
            }
        }

        return true;





    }

• javascript
• image
• validation
• file-upload

3 Answers 3

I am able to solve it. Below ar the correct codes. :)

JavaScript

<SCRIPT type="text/javascript">
    function ValidateFileUpload() {
        var fuData = document.getElementById('fileChooser');
        var FileUploadPath = fuData.value;

//To check if user upload any file
        if (FileUploadPath == '') {
            alert("Please upload an image");

        } else {
            var Extension = FileUploadPath.substring(
                    FileUploadPath.lastIndexOf('.') + 1).toLowerCase();

//The file uploaded is an image

if (Extension == "gif" || Extension == "png" || Extension == "bmp"
                    || Extension == "jpeg" || Extension == "jpg") {

// To Display
                if (fuData.files && fuData.files[0]) {
                    var reader = new FileReader();

                    reader.onload = function(e) {
                        $('#blah').attr('src', e.target.result);
                    }

                    reader.readAsDataURL(fuData.files[0]);
                }

            } 

//The file upload is NOT an image
else {
                alert("Photo only allows file types of GIF, PNG, JPG, JPEG and BMP. ");

            }
        }
    }
</SCRIPT>

The input on change:

<input type="file" name="dataFile" id="fileChooser" onchange="return ValidateFileUpload()" />

To display an image before uploaded:

<img src="images/noimg.jpg" id="blah">

We Solved it.. Here Is the Complete code :) This Code will help you to

1. Upload and display image (Not Upload Function)
2. Image Extension Validation
3. Reset img in case validation return false

function show(input) {
        debugger;
        var validExtensions = ['jpg','png','jpeg']; //array of valid extensions
        var fileName = input.files[0].name;
        var fileNameExt = fileName.substr(fileName.lastIndexOf('.') + 1);
        if ($.inArray(fileNameExt, validExtensions) == -1) {
            input.type = ''
            input.type = 'file'
            $('#user_img').attr('src',"");
            alert("Only these file types are accepted : "+validExtensions.join(', '));
        }
        else
        {
        if (input.files && input.files[0]) {
            var filerdr = new FileReader();
            filerdr.onload = function (e) {
                $('#user_img').attr('src', e.target.result);
            }
            filerdr.readAsDataURL(input.files[0]);
        }
        }
    }

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
<div class="form-group">
              Upload Your Image
                    <div class="col-md-10">
                        <div>
                            <img id="user_img"
                                 height="130"
                                 width="130"
                                 style="border:solid" />
                        </div>
                        <div>
                            <input type="file" title="search image" id="file" name="file" onchange="show(this)" />
                        </div>
                    </div>
                </div>

function isValidPhoto(fileName)
{
    var allowed_extensions = new Array("jpg","png");
    var file_extension = fileName.split('.').pop().toLowerCase(); 

    for(var i = 0; i <= allowed_extensions.length; i++)
    {
        if(allowed_extensions[i] == file_extension)
        {
            return true; // valid file extension
        }
    }

    return false;
}