cordova-android/framework/assets/js/file.js

/*
 * PhoneGap is available under *either* the terms of the modified BSD license *or* the
 * MIT License (2008). See http://opensource.org/licenses/alphabetical for full text.
 *
 * Copyright (c) 2005-2010, Nitobi Software Inc.
 * Copyright (c) 2010-2011, IBM Corporation
 */

if (!PhoneGap.hasResource("file")) {
PhoneGap.addResource("file");

/**
 * This class provides some useful information about a file.
 * This is the fields returned when navigator.fileMgr.getFileProperties()
 * is called.
 * @constructor
 */
var FileProperties = function(filePath) {
    this.filePath = filePath;
    this.size = 0;
    this.lastModifiedDate = null;
};

/**
 * Represents a single file.
 *
 * @constructor
 * @param name {DOMString} name of the file, without path information
 * @param fullPath {DOMString} the full path of the file, including the name
 * @param type {DOMString} mime type
 * @param lastModifiedDate {Date} last modified date
 * @param size {Number} size of the file in bytes
 */
var File = function(name, fullPath, type, lastModifiedDate, size) {
	this.name = name || null;
    this.fullPath = fullPath || null;
	this.type = type || null;
    this.lastModifiedDate = lastModifiedDate || null;
    this.size = size || 0;
};

/** @constructor */
var FileError = function() {
   this.code = null;
};

// File error codes
// Found in DOMException
FileError.NOT_FOUND_ERR = 1;
FileError.SECURITY_ERR = 2;
FileError.ABORT_ERR = 3;

// Added by this specification
FileError.NOT_READABLE_ERR = 4;
FileError.ENCODING_ERR = 5;
FileError.NO_MODIFICATION_ALLOWED_ERR = 6;
FileError.INVALID_STATE_ERR = 7;
FileError.SYNTAX_ERR = 8;
FileError.INVALID_MODIFICATION_ERR = 9;
FileError.QUOTA_EXCEEDED_ERR = 10;
FileError.TYPE_MISMATCH_ERR = 11;
FileError.PATH_EXISTS_ERR = 12;

//-----------------------------------------------------------------------------
// File manager
//-----------------------------------------------------------------------------

/** @constructor */
var FileMgr = function() {
};

FileMgr.prototype.getFileProperties = function(filePath) {
    return PhoneGap.exec(null, null, "File", "getFileProperties", [filePath]);
};

FileMgr.prototype.getFileBasePaths = function() {
};

FileMgr.prototype.testSaveLocationExists = function(successCallback, errorCallback) {
    return PhoneGap.exec(successCallback, errorCallback, "File", "testSaveLocationExists", []);
};

FileMgr.prototype.testFileExists = function(fileName, successCallback, errorCallback) {
    return PhoneGap.exec(successCallback, errorCallback, "File", "testFileExists", [fileName]);
};

FileMgr.prototype.testDirectoryExists = function(dirName, successCallback, errorCallback) {
    return PhoneGap.exec(successCallback, errorCallback, "File", "testDirectoryExists", [dirName]);
};

FileMgr.prototype.getFreeDiskSpace = function(successCallback, errorCallback) {
    return PhoneGap.exec(successCallback, errorCallback, "File", "getFreeDiskSpace", []);
};

FileMgr.prototype.write = function(fileName, data, position, successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "write", [fileName, data, position]);
};

FileMgr.prototype.truncate = function(fileName, size, successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "truncate", [fileName, size]);
};

FileMgr.prototype.readAsText = function(fileName, encoding, successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "readAsText", [fileName, encoding]);
};

FileMgr.prototype.readAsDataURL = function(fileName, successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "readAsDataURL", [fileName]);
};

PhoneGap.addConstructor(function() {
    if (typeof navigator.fileMgr === "undefined") {
        navigator.fileMgr = new FileMgr();
    }
});

//-----------------------------------------------------------------------------
// File Reader
//-----------------------------------------------------------------------------
// TODO: All other FileMgr function operate on the SD card as root.  However,
//       for FileReader & FileWriter the root is not SD card.  Should this be changed?

/**
 * This class reads the mobile device file system.
 *
 * For Android:
 *      The root directory is the root of the file system.
 *      To read from the SD card, the file name is "sdcard/my_file.txt"
 * @constructor
 */
var FileReader = function() {
    this.fileName = "";

    this.readyState = 0;

    // File data
    this.result = null;

    // Error
    this.error = null;

    // Event handlers
    this.onloadstart = null;    // When the read starts.
    this.onprogress = null;     // While reading (and decoding) file or fileBlob data, and reporting partial file data (progess.loaded/progress.total)
    this.onload = null;         // When the read has successfully completed.
    this.onerror = null;        // When the read has failed (see errors).
    this.onloadend = null;      // When the request has completed (either in success or failure).
    this.onabort = null;        // When the read has been aborted. For instance, by invoking the abort() method.
};

// States
FileReader.EMPTY = 0;
FileReader.LOADING = 1;
FileReader.DONE = 2;

/**
 * Abort reading file.
 */
FileReader.prototype.abort = function() {
    var evt;
    this.readyState = FileReader.DONE;
    this.result = null;

    // set error
    var error = new FileError();
    error.code = error.ABORT_ERR;
    this.error = error;

    // If error callback
    if (typeof this.onerror === "function") {
        this.onerror({"type":"error", "target":this});
    }
    // If abort callback
    if (typeof this.onabort === "function") {
        this.onabort({"type":"abort", "target":this});
    }
    // If load end callback
    if (typeof this.onloadend === "function") {
        this.onloadend({"type":"loadend", "target":this});
    }
};

/**
 * Read text file.
 *
 * @param file          {File} File object containing file properties
 * @param encoding      [Optional] (see http://www.iana.org/assignments/character-sets)
 */
FileReader.prototype.readAsText = function(file, encoding) {
    this.fileName = "";
	if (typeof file.fullPath === "undefined") {
		this.fileName = file;
	} else {
		this.fileName = file.fullPath;
	}

    // LOADING state
    this.readyState = FileReader.LOADING;

    // If loadstart callback
    if (typeof this.onloadstart === "function") {
        this.onloadstart({"type":"loadstart", "target":this});
    }

    // Default encoding is UTF-8
    var enc = encoding ? encoding : "UTF-8";

    var me = this;

    // Read file
    navigator.fileMgr.readAsText(this.fileName, enc,

        // Success callback
        function(r) {
            var evt;

            // If DONE (cancelled), then don't do anything
            if (me.readyState === FileReader.DONE) {
                return;
            }

            // Save result
            me.result = r;

            // If onload callback
            if (typeof me.onload === "function") {
                me.onload({"type":"load", "target":me});
            }

            // DONE state
            me.readyState = FileReader.DONE;

            // If onloadend callback
            if (typeof me.onloadend === "function") {
                me.onloadend({"type":"loadend", "target":me});
            }
        },

        // Error callback
        function(e) {
            var evt;
            // If DONE (cancelled), then don't do anything
            if (me.readyState === FileReader.DONE) {
                return;
            }

            // Save error
		    me.error = e;

            // If onerror callback
            if (typeof me.onerror === "function") {
                me.onerror({"type":"error", "target":me});
            }

            // DONE state
            me.readyState = FileReader.DONE;

            // If onloadend callback
            if (typeof me.onloadend === "function") {
                me.onloadend({"type":"loadend", "target":me});
            }
        }
        );
};


/**
 * Read file and return data as a base64 encoded data url.
 * A data url is of the form:
 *      data:[<mediatype>][;base64],<data>
 *
 * @param file          {File} File object containing file properties
 */
FileReader.prototype.readAsDataURL = function(file) {
	this.fileName = "";
    if (typeof file.fullPath === "undefined") {
        this.fileName = file;
    } else {
        this.fileName = file.fullPath;
    }

    // LOADING state
    this.readyState = FileReader.LOADING;

    // If loadstart callback
    if (typeof this.onloadstart === "function") {
        this.onloadstart({"type":"loadstart", "target":this});
    }

    var me = this;

    // Read file
    navigator.fileMgr.readAsDataURL(this.fileName,

        // Success callback
        function(r) {
            var evt;

            // If DONE (cancelled), then don't do anything
            if (me.readyState === FileReader.DONE) {
                return;
            }

            // Save result
            me.result = r;

            // If onload callback
            if (typeof me.onload === "function") {
                me.onload({"type":"load", "target":me});
            }

            // DONE state
            me.readyState = FileReader.DONE;

            // If onloadend callback
            if (typeof me.onloadend === "function") {
                me.onloadend({"type":"loadend", "target":me});
            }
        },

        // Error callback
        function(e) {
            var evt;
            // If DONE (cancelled), then don't do anything
            if (me.readyState === FileReader.DONE) {
                return;
            }

            // Save error
            me.error = e;

            // If onerror callback
            if (typeof me.onerror === "function") {
                me.onerror({"type":"error", "target":me});
            }

            // DONE state
            me.readyState = FileReader.DONE;

            // If onloadend callback
            if (typeof me.onloadend === "function") {
                me.onloadend({"type":"loadend", "target":me});
            }
        }
        );
};

/**
 * Read file and return data as a binary data.
 *
 * @param file          {File} File object containing file properties
 */
FileReader.prototype.readAsBinaryString = function(file) {
    // TODO - Can't return binary data to browser.
    this.fileName = file;
};

/**
 * Read file and return data as a binary data.
 *
 * @param file          {File} File object containing file properties
 */
FileReader.prototype.readAsArrayBuffer = function(file) {
    // TODO - Can't return binary data to browser.
    this.fileName = file;
};

//-----------------------------------------------------------------------------
// File Writer
//-----------------------------------------------------------------------------

/**
 * This class writes to the mobile device file system.
 *
 * For Android:
 *      The root directory is the root of the file system.
 *      To write to the SD card, the file name is "sdcard/my_file.txt"
 *
 * @constructor
 * @param file {File} File object containing file properties
 * @param append if true write to the end of the file, otherwise overwrite the file
 */
var FileWriter = function(file) {
    this.fileName = "";
    this.length = 0;
	if (file) {
	    this.fileName = file.fullPath || file;
	    this.length = file.size || 0;
	}
    // default is to write at the beginning of the file
    this.position = 0;

    this.readyState = 0; // EMPTY

    this.result = null;

    // Error
    this.error = null;

    // Event handlers
    this.onwritestart = null;	// When writing starts
    this.onprogress = null;		// While writing the file, and reporting partial file data
    this.onwrite = null;		// When the write has successfully completed.
    this.onwriteend = null;		// When the request has completed (either in success or failure).
    this.onabort = null;		// When the write has been aborted. For instance, by invoking the abort() method.
    this.onerror = null;		// When the write has failed (see errors).
};

// States
FileWriter.INIT = 0;
FileWriter.WRITING = 1;
FileWriter.DONE = 2;

/**
 * Abort writing file.
 */
FileWriter.prototype.abort = function() {
    // check for invalid state
	if (this.readyState === FileWriter.DONE || this.readyState === FileWriter.INIT) {
		throw FileError.INVALID_STATE_ERR;
	}

    // set error
    var error = new FileError(), evt;
    error.code = error.ABORT_ERR;
    this.error = error;

    // If error callback
    if (typeof this.onerror === "function") {
        this.onerror({"type":"error", "target":this});
    }
    // If abort callback
    if (typeof this.onabort === "function") {
        this.onabort({"type":"abort", "target":this});
    }

    this.readyState = FileWriter.DONE;

    // If write end callback
    if (typeof this.onwriteend == "function") {
        this.onwriteend({"type":"writeend", "target":this});
    }
};

/**
 * Writes data to the file
 *
 * @param text to be written
 */
FileWriter.prototype.write = function(text) {
	// Throw an exception if we are already writing a file
	if (this.readyState === FileWriter.WRITING) {
		throw FileError.INVALID_STATE_ERR;
	}

    // WRITING state
    this.readyState = FileWriter.WRITING;

    var me = this;

    // If onwritestart callback
    if (typeof me.onwritestart === "function") {
        me.onwritestart({"type":"writestart", "target":me});
    }

    // Write file
    navigator.fileMgr.write(this.fileName, text, this.position,

        // Success callback
        function(r) {
            var evt;
            // If DONE (cancelled), then don't do anything
            if (me.readyState === FileWriter.DONE) {
                return;
            }

            // position always increases by bytes written because file would be extended
            me.position += r;
            // The length of the file is now where we are done writing.
            me.length = me.position;

            // If onwrite callback
            if (typeof me.onwrite === "function") {
                me.onwrite({"type":"write", "target":me});
            }

            // DONE state
            me.readyState = FileWriter.DONE;

            // If onwriteend callback
            if (typeof me.onwriteend === "function") {
                me.onwriteend({"type":"writeend", "target":me});
            }
        },

        // Error callback
        function(e) {
            var evt;

            // If DONE (cancelled), then don't do anything
            if (me.readyState === FileWriter.DONE) {
                return;
            }

            // Save error
            me.error = e;

            // If onerror callback
            if (typeof me.onerror === "function") {
                me.onerror({"type":"error", "target":me});
            }

            // DONE state
            me.readyState = FileWriter.DONE;

            // If onwriteend callback
            if (typeof me.onwriteend === "function") {
                me.onwriteend({"type":"writeend", "target":me});
            }
        }
        );

};

/**
 * Moves the file pointer to the location specified.
 *
 * If the offset is a negative number the position of the file
 * pointer is rewound.  If the offset is greater than the file
 * size the position is set to the end of the file.
 *
 * @param offset is the location to move the file pointer to.
 */
FileWriter.prototype.seek = function(offset) {
    // Throw an exception if we are already writing a file
    if (this.readyState === FileWriter.WRITING) {
        throw FileError.INVALID_STATE_ERR;
    }

    if (!offset) {
        return;
    }

    // See back from end of file.
    if (offset < 0) {
		this.position = Math.max(offset + this.length, 0);
	}
    // Offset is bigger then file size so set position
    // to the end of the file.
	else if (offset > this.length) {
		this.position = this.length;
	}
    // Offset is between 0 and file size so set the position
    // to start writing.
	else {
		this.position = offset;
	}
};

/**
 * Truncates the file to the size specified.
 *
 * @param size to chop the file at.
 */
FileWriter.prototype.truncate = function(size) {
	// Throw an exception if we are already writing a file
	if (this.readyState === FileWriter.WRITING) {
		throw FileError.INVALID_STATE_ERR;
	}

    // WRITING state
    this.readyState = FileWriter.WRITING;

    var me = this;

    // If onwritestart callback
    if (typeof me.onwritestart === "function") {
        me.onwritestart({"type":"writestart", "target":this});
    }

    // Write file
    navigator.fileMgr.truncate(this.fileName, size,

        // Success callback
        function(r) {
            var evt;
            // If DONE (cancelled), then don't do anything
            if (me.readyState === FileWriter.DONE) {
                return;
            }

            // Update the length of the file
            me.length = r;
            me.position = Math.min(me.position, r);

            // If onwrite callback
            if (typeof me.onwrite === "function") {
                me.onwrite({"type":"write", "target":me});
            }

            // DONE state
            me.readyState = FileWriter.DONE;

            // If onwriteend callback
            if (typeof me.onwriteend === "function") {
                me.onwriteend({"type":"writeend", "target":me});
            }
        },

        // Error callback
        function(e) {
            var evt;
            // If DONE (cancelled), then don't do anything
            if (me.readyState === FileWriter.DONE) {
                return;
            }

            // Save error
            me.error = e;

            // If onerror callback
            if (typeof me.onerror === "function") {
                me.onerror({"type":"error", "target":me});
            }

            // DONE state
            me.readyState = FileWriter.DONE;

            // If onwriteend callback
            if (typeof me.onwriteend === "function") {
                me.onwriteend({"type":"writeend", "target":me});
            }
        }
    );
};

/**
 * Information about the state of the file or directory
 *
 * @constructor
 * {Date} modificationTime (readonly)
 */
var Metadata = function() {
    this.modificationTime=null;
};

/**
 * Supplies arguments to methods that lookup or create files and directories
 *
 * @constructor
 * @param {boolean} create file or directory if it doesn't exist
 * @param {boolean} exclusive if true the command will fail if the file or directory exists
 */
var Flags = function(create, exclusive) {
    this.create = create || false;
    this.exclusive = exclusive || false;
};

/**
 * An interface representing a file system
 *
 * @constructor
 * {DOMString} name the unique name of the file system (readonly)
 * {DirectoryEntry} root directory of the file system (readonly)
 */
var FileSystem = function() {
    this.name = null;
    this.root = null;
};

/**
 * An interface that lists the files and directories in a directory.
 * @constructor
 */
var DirectoryReader = function(fullPath){
    this.fullPath = fullPath || null;
};

/**
 * Returns a list of entries from a directory.
 *
 * @param {Function} successCallback is called with a list of entries
 * @param {Function} errorCallback is called with a FileError
 */
DirectoryReader.prototype.readEntries = function(successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "readEntries", [this.fullPath]);
};

/**
 * An interface representing a directory on the file system.
 *
 * @constructor
 * {boolean} isFile always false (readonly)
 * {boolean} isDirectory always true (readonly)
 * {DOMString} name of the directory, excluding the path leading to it (readonly)
 * {DOMString} fullPath the absolute full path to the directory (readonly)
 * {FileSystem} filesystem on which the directory resides (readonly)
 */
var DirectoryEntry = function() {
    this.isFile = false;
    this.isDirectory = true;
    this.name = null;
    this.fullPath = null;
    this.filesystem = null;
};

/**
 * Copies a directory to a new location
 *
 * @param {DirectoryEntry} parent the directory to which to copy the entry
 * @param {DOMString} newName the new name of the entry, defaults to the current name
 * @param {Function} successCallback is called with the new entry
 * @param {Function} errorCallback is called with a FileError
 */
DirectoryEntry.prototype.copyTo = function(parent, newName, successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "copyTo", [this.fullPath, parent, newName]);
};

/**
 * Looks up the metadata of the entry
 *
 * @param {Function} successCallback is called with a Metadata object
 * @param {Function} errorCallback is called with a FileError
 */
DirectoryEntry.prototype.getMetadata = function(successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "getMetadata", [this.fullPath]);
};

/**
 * Gets the parent of the entry
 *
 * @param {Function} successCallback is called with a parent entry
 * @param {Function} errorCallback is called with a FileError
 */
DirectoryEntry.prototype.getParent = function(successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "getParent", [this.fullPath]);
};

/**
 * Moves a directory to a new location
 *
 * @param {DirectoryEntry} parent the directory to which to move the entry
 * @param {DOMString} newName the new name of the entry, defaults to the current name
 * @param {Function} successCallback is called with the new entry
 * @param {Function} errorCallback is called with a FileError
 */
DirectoryEntry.prototype.moveTo = function(parent, newName, successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "moveTo", [this.fullPath, parent, newName]);
};

/**
 * Removes the entry
 *
 * @param {Function} successCallback is called with no parameters
 * @param {Function} errorCallback is called with a FileError
 */
DirectoryEntry.prototype.remove = function(successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "remove", [this.fullPath]);
};

/**
 * Returns a URI that can be used to identify this entry.
 *
 * @param {DOMString} mimeType for a FileEntry, the mime type to be used to interpret the file, when loaded through this URI.
 * @return uri
 */
DirectoryEntry.prototype.toURI = function(mimeType) {
    return "file://" + this.fullPath;
};

/**
 * Creates a new DirectoryReader to read entries from this directory
 */
DirectoryEntry.prototype.createReader = function(successCallback, errorCallback) {
    return new DirectoryReader(this.fullPath);
};

/**
 * Creates or looks up a directory
 *
 * @param {DOMString} path either a relative or absolute path from this directory in which to look up or create a directory
 * @param {Flags} options to create or excluively create the directory
 * @param {Function} successCallback is called with the new entry
 * @param {Function} errorCallback is called with a FileError
 */
DirectoryEntry.prototype.getDirectory = function(path, options, successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "getDirectory", [this.fullPath, path, options]);
};

/**
 * Creates or looks up a file
 *
 * @param {DOMString} path either a relative or absolute path from this directory in which to look up or create a file
 * @param {Flags} options to create or excluively create the file
 * @param {Function} successCallback is called with the new entry
 * @param {Function} errorCallback is called with a FileError
 */
DirectoryEntry.prototype.getFile = function(path, options, successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "getFile", [this.fullPath, path, options]);
};

/**
 * Deletes a directory and all of it's contents
 *
 * @param {Function} successCallback is called with no parameters
 * @param {Function} errorCallback is called with a FileError
 */
DirectoryEntry.prototype.removeRecursively = function(successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "removeRecursively", [this.fullPath]);
};

/**
 * An interface representing a directory on the file system.
 *
 * @constructor
 * {boolean} isFile always true (readonly)
 * {boolean} isDirectory always false (readonly)
 * {DOMString} name of the file, excluding the path leading to it (readonly)
 * {DOMString} fullPath the absolute full path to the file (readonly)
 * {FileSystem} filesystem on which the directory resides (readonly)
 */
var FileEntry = function() {
    this.isFile = true;
    this.isDirectory = false;
    this.name = null;
    this.fullPath = null;
    this.filesystem = null;
};

/**
 * Copies a file to a new location
 *
 * @param {DirectoryEntry} parent the directory to which to copy the entry
 * @param {DOMString} newName the new name of the entry, defaults to the current name
 * @param {Function} successCallback is called with the new entry
 * @param {Function} errorCallback is called with a FileError
 */
FileEntry.prototype.copyTo = function(parent, newName, successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "copyTo", [this.fullPath, parent, newName]);
};

/**
 * Looks up the metadata of the entry
 *
 * @param {Function} successCallback is called with a Metadata object
 * @param {Function} errorCallback is called with a FileError
 */
FileEntry.prototype.getMetadata = function(successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "getMetadata", [this.fullPath]);
};

/**
 * Gets the parent of the entry
 *
 * @param {Function} successCallback is called with a parent entry
 * @param {Function} errorCallback is called with a FileError
 */
FileEntry.prototype.getParent = function(successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "getParent", [this.fullPath]);
};

/**
 * Moves a directory to a new location
 *
 * @param {DirectoryEntry} parent the directory to which to move the entry
 * @param {DOMString} newName the new name of the entry, defaults to the current name
 * @param {Function} successCallback is called with the new entry
 * @param {Function} errorCallback is called with a FileError
 */
FileEntry.prototype.moveTo = function(parent, newName, successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "moveTo", [this.fullPath, parent, newName]);
};

/**
 * Removes the entry
 *
 * @param {Function} successCallback is called with no parameters
 * @param {Function} errorCallback is called with a FileError
 */
FileEntry.prototype.remove = function(successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "remove", [this.fullPath]);
};

/**
 * Returns a URI that can be used to identify this entry.
 *
 * @param {DOMString} mimeType for a FileEntry, the mime type to be used to interpret the file, when loaded through this URI.
 * @return uri
 */
FileEntry.prototype.toURI = function(mimeType) {
    return "file://" + this.fullPath;
};

/**
 * Creates a new FileWriter associated with the file that this FileEntry represents.
 *
 * @param {Function} successCallback is called with the new FileWriter
 * @param {Function} errorCallback is called with a FileError
 */
FileEntry.prototype.createWriter = function(successCallback, errorCallback) {
    this.file(function(filePointer) {
        var writer = new FileWriter(filePointer);
    
        if (writer.fileName === null || writer.fileName === "") {
            if (typeof errorCallback == "function") {
                errorCallback({
                    "code": FileError.INVALID_STATE_ERR
                });
            }
        }
    
        if (typeof successCallback == "function") {
            successCallback(writer);
        }       
    }, errorCallback);
};

/**
 * Returns a File that represents the current state of the file that this FileEntry represents.
 *
 * @param {Function} successCallback is called with the new File object
 * @param {Function} errorCallback is called with a FileError
 */
FileEntry.prototype.file = function(successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "getFileMetadata", [this.fullPath]);
};

/** @constructor */
var LocalFileSystem = function() {
};

// File error codes
LocalFileSystem.TEMPORARY = 0;
LocalFileSystem.PERSISTENT = 1;
LocalFileSystem.RESOURCE = 2;
LocalFileSystem.APPLICATION = 3;

/**
 * Requests a filesystem in which to store application data.
 *
 * @param {int} type of file system being requested
 * @param {Function} successCallback is called with the new FileSystem
 * @param {Function} errorCallback is called with a FileError
 */
LocalFileSystem.prototype.requestFileSystem = function(type, size, successCallback, errorCallback) {
    if (type < 0 || type > 3) {
        if (typeof errorCallback == "function") {
            errorCallback({
                "code": FileError.SYNTAX_ERR
            });
        }
    }
    else {
        PhoneGap.exec(successCallback, errorCallback, "File", "requestFileSystem", [type, size]);
    }
};

/**
 *
 * @param {DOMString} uri referring to a local file in a filesystem
 * @param {Function} successCallback is called with the new entry
 * @param {Function} errorCallback is called with a FileError
 */
LocalFileSystem.prototype.resolveLocalFileSystemURI = function(uri, successCallback, errorCallback) {
    PhoneGap.exec(successCallback, errorCallback, "File", "resolveLocalFileSystemURI", [uri]);
};

/**
* This function returns and array of contacts.  It is required as we need to convert raw
* JSON objects into concrete Contact objects.  Currently this method is called after
* navigator.service.contacts.find but before the find methods success call back.
*
* @param a JSON Objects that need to be converted to DirectoryEntry or FileEntry objects.
* @returns an entry
*/
LocalFileSystem.prototype._castFS = function(pluginResult) {
    var entry = null;
    entry = new DirectoryEntry();
    entry.isDirectory = pluginResult.message.root.isDirectory;
    entry.isFile = pluginResult.message.root.isFile;
    entry.name = pluginResult.message.root.name;
    entry.fullPath = pluginResult.message.root.fullPath;
    pluginResult.message.root = entry;
    return pluginResult;
};

LocalFileSystem.prototype._castEntry = function(pluginResult) {
    var entry = null;
    if (pluginResult.message.isDirectory) {
        console.log("This is a dir");
        entry = new DirectoryEntry();
    }
    else if (pluginResult.message.isFile) {
        console.log("This is a file");
        entry = new FileEntry();
    }
    entry.isDirectory = pluginResult.message.isDirectory;
    entry.isFile = pluginResult.message.isFile;
    entry.name = pluginResult.message.name;
    entry.fullPath = pluginResult.message.fullPath;
    pluginResult.message = entry;
    return pluginResult;
};

LocalFileSystem.prototype._castEntries = function(pluginResult) {
    var entries = pluginResult.message;
    var retVal = [];
    for (var i=0; i<entries.length; i++) {
        retVal.push(window.localFileSystem._createEntry(entries[i]));
    }
    pluginResult.message = retVal;
    return pluginResult;
};

LocalFileSystem.prototype._createEntry = function(castMe) {
    var entry = null;
    if (castMe.isDirectory) {
        console.log("This is a dir");
        entry = new DirectoryEntry();
    }
    else if (castMe.isFile) {
        console.log("This is a file");
        entry = new FileEntry();
    }
    entry.isDirectory = castMe.isDirectory;
    entry.isFile = castMe.isFile;
    entry.name = castMe.name;
    entry.fullPath = castMe.fullPath;
    return entry;
};

LocalFileSystem.prototype._castDate = function(pluginResult) {
    if (pluginResult.message.modificationTime) {
        var modTime = new Date(pluginResult.message.modificationTime);
        pluginResult.message.modificationTime = modTime;
    }
    else if (pluginResult.message.lastModifiedDate) {
        var file = new File();
        file.size = pluginResult.message.size;
        file.type = pluginResult.message.type;
        file.name = pluginResult.message.name;
        file.fullPath = pluginResult.message.fullPath;
        file.lastModifiedDate = new Date(pluginResult.message.lastModifiedDate);
        pluginResult.message = file;
    }
    return pluginResult;
};

/**
 * Add the FileSystem interface into the browser.
 */
PhoneGap.addConstructor(function() {
	var pgLocalFileSystem = new LocalFileSystem();
	// Needed for cast methods
    if(typeof window.localFileSystem == "undefined") window.localFileSystem  = pgLocalFileSystem;
    if(typeof window.requestFileSystem == "undefined") window.requestFileSystem  = pgLocalFileSystem.requestFileSystem;
    if(typeof window.resolveLocalFileSystemURI == "undefined") window.resolveLocalFileSystemURI = pgLocalFileSystem.resolveLocalFileSystemURI;
});
}