How to have jQuery restrict file types on upload

Question

I would like to have jQuery limit a file upload field to only jpg jpeg  png  and gif  I am doing backend checking with PHP already  I am running my submit button through a JavaScript function already so I really just need to know how to check for the file types before submit or alert

User · Answer

input name  btnsubmit     attr  disabled   true          input name  filphoto     change function          var ext   this value match            1       switch  ext             case  jpg       case  jpeg       case  png       case  bmp              input name  btnsubmit     attr  disabled   false       break      default          alert  This is not an allowed file type                input name  btnsubmit     attr  disabled   true           this value

User · Answer

Don t want to check rather on MIME than on whatever extention the user is lying  If so then it s less than one line    lt input type  file  id  userfile  accept  image   video    required   gt

User · Answer

You could use the validation plugin for jQuery  http   docs jquery com Plugins Validation  It happens to have an accept   rule that does exactly what you need  http   docs jquery com Plugins Validation Methods accept extension  Note that controlling file extension is not bullet proof since it is in no way related to the mimetype of the file  So you could have a  png that s a word document and a  doc that s a perfectly valid png image  So don t forget to make more controls server-side

User · Answer

You can get the value of a file field just the same as any other field  You can t alter it  however   So to superficially check if a file has the right extension  you could do something like this   var ext       my file field   val   split      pop   toLowerCase    if   inArray ext    gif   png   jpg   jpeg       -1        alert  invalid extension

User · Answer

function validateFileExtensions            var validFileExtensions     jpg    jpeg    gif    png            var fileErrors   new Array                 input file   each function                var file     this  value              var ext   file split      pop                if    inArray  ext  validFileExtensions      -1                    fileErrors push file                                      if  fileErrors length  gt  0                var errorContainer       validation-errors                for var i 0  i  lt  fileErrors length  i                     errorContainer append   lt label for  title  class  error  gt   File    file    do not have a valid format  lt  label gt                               return false                    return true

User · Answer

No plugin necessary for just this task  Cobbled this together from a couple other scripts      INPUT type  file     change function          var ext   this value match            1       switch  ext            case  jpg           case  jpeg           case  png           case  gif                   uploadButton   attr  disabled   false               break          default              alert  This is not an allowed file type                 this value                   The trick here is to set the upload button to disabled unless and until a valid file type is selected

User · Answer

for my case i used the following codes         if        gif jpg jpeg tiff png   i  test fileName                       alert  You must select an image file only

User · Answer

For the front-end it is pretty convenient to put  accept  attribute if you are using a file field   Example    lt input id  file  type  file  name  file  size  30          accept  image jpg image png image jpeg image gif     gt    A couple of important notes    The accept attribute is supported in Internet Explorer 10  Firefox  Opera  Chrome  and Safari 6   It will show text for file extension differently in the file browser dialog from different browsers

User · Answer

This code works fine  but the only issue is if the file format is other than specified options  it shows an alert message but it displays the file name while it should be neglecting it       ff2   change                  function                          var fileExtension     jpeg    jpg    pdf                        if    inArray   this  val   split      pop   toLowerCase    fileExtension     -1                            alert  Only   jpeg    jpg    pdf  formats are allowed                             return false

User · Answer

If you re dealing with multiple  html 5  file uploads  I took the top suggested comment and modified it a little       var files       file1   0  files      var len       file1   get 0  files length       for  var i   0  i  lt  len  i               f   files i            var ext   f name split      pop   toLowerCase            if    inArray ext    gif    png    jpg    jpeg       -1                alert  invalid extension

User · Answer

Here is a simple code for javascript validation  and after it validates it will clean the input file    lt input type  file  id  image  accept  image    onChange  validate this value    gt   function validate file        var ext   file split           ext   ext ext length-1  toLowerCase              var arrayExtensions     jpg     jpeg    png    bmp    gif         if  arrayExtensions lastIndexOf ext     -1            alert  Wrong extension type                 image   val

User · Answer

I try to write working code example  I test it and everything works   Hare is code    HTML    lt input type  file  class  attachment input  name  file  onchange  checkFileSize this   Model MaxSize ToString    Html Raw Json Encode Model FileExtensionsList       gt    Javascript      function for check attachment size and extention match function checkFileSize element  maxSize  extentionsArray        var val     element  val      get file value      var ext   val substring val lastIndexOf        1  toLowerCase       get file extention      if    inArray ext  extentionsArray     -1            alert  false extension                var fileSize      element  0  files 0  size   1024   1024     size in MB     if  fileSize  gt  maxSize            alert  Large file      if Maxsize from Model  gt  real file size alert this

User · Answer

lt form enctype  multipart form-data  gt      lt input name  file  type  file    gt      lt input type  submit  value  Upload    gt   lt  form gt   lt script gt     input type file    change function        var file   this files 0       name   file name      size   file size      type   file type        your validation      lt  script gt

User · Answer

This example allows to upload PNG image only   HTML   lt input type  file  class  form-control  id  FileUpload1  accept  image png    gt    JS      FileUpload1   change                  function                          var fileExtension     png                        if    inArray   this  val   split      pop   toLowerCase    fileExtension     -1                            alert  Only   png  format is allowed                             this value          Clean field                         return false

[javascript] How to have jQuery restrict file types on upload?

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