Cordova read file

fetchFile.js

window.fetchFile = function(fileName) {


  function getFileEntry(fullFileName) {
    return new Promise((resolve, reject) => {
      window.resolveLocalFileSystemURL(fullFileName, resolve, reject);
    });
  }


  function readFile(fileEntry){
    return new Promise((resolve, reject) => {
      fileEntry.file(function (file) {
        const reader = new FileReader();

        reader.onloadend = function () {
          resolve(this.result);
        };
        reader.readAsText(file);
      }, reject);
    });
  }

  function fetchFile(fileName){
    return getFileEntry(fileName).then(fileEntry => {
      return readFile(fileEntry);
    });
  }

  return fetchFile(fileName);
}