Filesystem example

The index.html file containing JavaScript that makes use of the Filesystem API functionality is listed below.

<!DOCTYPE html>
<html manifest="manifest.appcache">
  <head>
    <title>Filesystem API usage example</title>
    <link rel="x-antenna-managed-webapp-descriptor" href="webapp-descriptor.xml" />
    
    <script type="text/javascript">
      var loaded = false;
      window.onLaunchboxLoaded = function () {
          loaded = true;
          initFS();
      }
        function printText(str) {
            var d = document.getElementById('text-box');
            d.appendChild(document.createTextNode(str));
            d.appendChild(document.createElement('br'));
            d.scrollTop = d.scrollHeight;
        }

        // FileEntry methods
          function initFS() {
          alert("initfs");
          requestFileSystem(window.TEMPORARY, 1024*1024, function(filesystem) {
          fs = filesystem;
          }, errorHandler);
          }

      function errorHandler(e) {
        var msg = '';
        switch (e.code) {
          case FileError.QUOTA_EXCEEDED_ERR:
          msg = 'QUOTA_EXCEEDED_ERR';
        break;
          case FileError.NOT_FOUND_ERR:
          msg = 'NOT_FOUND_ERR';
        break;
          case FileError.SECURITY_ERR:
          msg = 'SECURITY_ERR';
        break;
          case FileError.INVALID_MODIFICATION_ERR:
          msg = 'INVALID_MODIFICATION_ERR';
        break;
         case FileError.INVALID_STATE_ERR:
         msg = 'INVALID_STATE_ERR';
        break;
        default:
          console.log(JSON.stringify(e));
          msg = e.name;
        break;
        };
        printText('Error: ' + msg);
      }


      
      function createFile() {
          fs.root.getFile(document.getElementById("txtFieldFile").value, { 'create' : true }, function(fileEntry) {
                  printText("Created " + fileEntry.name + " file.");
              }, errorHandler);
      }
      
      function writeToFile(){
      fs.root.getFile(document.getElementById("txtFieldFile").value, { 'create' : false }, function(fileEntry) {
      var writer = fileEntry.createWriter();
      writer.write(document.getElementById("txtFileContent").value);
      writer.onwriteend = function(event) {
        printText("Done");
      };
      writer.onerror = function(event) {
        printText("Error occured.");
      }
    }, errorHandler);
      }
      
      function readFile(){
        fs.root.getFile(document.getElementById("txtFieldFile").value, {}, function(entry) {
          entry.file(function(fd) {
            var reader = new FileReader();
            reader.onload = function(event) {
              printText("Read: " + reader.result);
            };
            reader.onerror = function(event) {
              printText("Error occured.");
            };
            reader.readAsText(fd);
          }, errorHandler);
        }, errorHandler);
      }
      
      function deleteFile(){
        fs.root.getFile(document.getElementById("txtFieldFile").value, { 'create' : false }, function(fileEntry) {
          fileEntry.remove(function() {
            printText("File removed.");
          }, errorHandler);
        }, errorHandler);
      }
      //directories
      
      function createDir(){
        fs.root.getDirectory("fooDir", { 'create' : true }, function(dirEntry) {
          printText("Created " + dirEntry.name + " dir.");
        }, errorHandler);
      }
    function lookupFiles(){
      var dirReader = fs.root.createReader();
      dirReader.readEntries(function(entries) {
        if (!entries.length) {
          printText('Filesystem is empty.');
        } else {
          printText(JSON.stringify(entries));
        }
        initFS();
      }, false);
    }
    
    function removeDir(){
      fs.root.getDirectory('fooDir', {}, function(dirEntry) {
        dirEntry.removeRecursively(function(){
          printText('Directory successfully removed.');
        }, errorHandler);
      }, errorHandler);
    }
    
    function clearOutput(){
      var d = document.getElementById('text-box');
      d.innerHTML = "";
    }

  
    </script>
  </head>
  
  
  <body>
    <header>
      <h3><span>Filesystem API usage example</span>
      </h3>
    </header>
    <!--
        <input type="button" onclick="checkApi();" value="Check API" /><br />
        -->
    <input type="text" id="txtFieldFile" value="sampleFileName.txt" />
    <input type="text" id="txtFileContent" value="This is sample file content." />
    <hr />
    <input type="button" onclick="createFile();" value="create file" /><br />
    <input type="button" onclick="writeToFile();" value="write to file" /><br />
    <input type="button" onclick="readFile();" value="read file" /><br />
    <input type="button" onclick="deleteFile();" value="delete file" /><br />
    <input type="button" onclick="createDir();" value="create directory" /><br />
    <input type="button" onclick="lookupFiles();" value="lookup directory" /><br />
    <input type="button" onclick="removeDir();" value="delete directory" /><br />
    <input type="button" onclick="clearOutput();" value="clear" />
    <div id="text-box"></div>
  </body>
</html>

The contents of the cache manifest file called manifest.appcache for this application are listed below:

CACHE MANIFEST

CACHE:
index.html

NETWORK:
*

The webapp-descriptor.xml file for this application is defined in the following way:

<?xml version="1.0" encoding="UTF-8"?>
<webapp-descriptor xmlns="http://www.pega.com/application-hosting/web-app-descriptor/2.0">
    <id>com.pega.sample.filesystem</id>
    <version>1.0.0</version>
    <name>Filesystem API usage example</name>
</webapp-descriptor>

Filesystem

Filesystem example

Related topics