How to check a file's existence in phone directory with phonegap

Question

I\'m writing an Android application with Phonegap 1.4.1 and Sencha that downloads and reads pdf files. How can I check whether the file exists in the phone directory using e

Answer 1

I took @Thomas Soti answer above and trimmed it down to a simple yes/no response.

function fileExists(fileName) {
  window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, function(fileSystem){
      fileSystem.root.getFile(cordova.file.dataDirectory + fileName, { create: false }, function(){return true}, function(){return false});
  }, function(){return false}); //of requestFileSystem
}
// called as
if (fileExists("blah.json")) {
or
var fe = fileExists("blah.json) ;

Correction....this does NOT work. I am working on the fix now.

Answer 2

You could check if the file exists using the FileReader object from phonegap. You could check the following:

var reader = new FileReader();
var fileSource = <here is your file path>

reader.onloadend = function(evt) {

    if(evt.target.result == null) {
       // If you receive a null value the file doesn't exists
    } else {
        // Otherwise the file exists
    }         
};

// We are going to check if the file exists
reader.readAsDataURL(fileSource);   

Answer 3

The above answers did not work for me, but this did :

window.resolveLocalFileSystemURL(fullFilePath, success, fail);

from : http://www.raymondcamden.com/2014/07/01/Cordova-Sample-Check-for-a-file-and-download-if-it-isnt-there

Answer 4

I've tested the following code snippet, and works quite well for me in PhoneGap 3.1

String.prototype.fileExists = function() {
filename = this.trim();

var response = jQuery.ajax({
    url: filename,
    type: 'HEAD',
    async: false
}).status;  

return (response != "200") ? false : true;}

if (yourFileFullPath.fileExists())
{}

Answer 5

I get a handle to the file using the .getFile('fileName',{create:false},success,failure) method. If I get the success callback the file is there, otherwise any failure implies that there is a problem with the file.

Answer 6

Darkaico, Kurt and thomas answers didn't work for me. Here's what worked for me.

$.ajax({
url:'file///sdcard/myfile.txt',
type:'HEAD',
error: function()
{
    //file not exists
alert('file does not exist');
},
success: function()
{
    //file exists
alert('the file is here');
}
});