Github user nikhilkh commented on a diff in the pull request:
https://github.com/apache/cordova-plugin-file-transfer/pull/136#discussion_r58437200
--- Diff: README.md ---
@@ -315,3 +315,231 @@ If you are upgrading to a new (1.0.0 or newer)
version of File, and you have pre
cdvfile://localhost/persistent/path/to/file
which can be used in place of the absolute file path in both `download()`
and `upload()` methods.
+
+## Sample: Download and Upload Files
+
+Use the File-Transfer plugin to upload and download files. In these
examples, we demonstrate several tasks like:
+
+* Downloading a binary file to the application cache
+* Uploading a file created in your application's root
+* Downloading the uploaded file
+
+## Download a Binary File to the application cache
+
+Use the File plugin with the File-Transfer plugin to provide a target for
the files that you download (the target must be a FileEntry object). Before you
download the file, create a DirectoryEntry object by using
`resolveLocalFileSystemURL` and calling `fs.root` in the success callback. Use
the `getFile` method of DirectoryEntry to create the target file.
+
+```
+window.requestFileSystem(window.TEMPORARY, 5 * 1024 * 1024, function (fs) {
+
+ console.log('file system open: ' + fs.name);
+
+ // Make sure you add the domain name to the Content-Security-Policy
<meta> element.
+ var url = 'http://cordova.apache.org/static/img/cordova_bot.png';
+ fs.root.getFile('downloaded-image.png', { create: true, exclusive:
false }, function (fileEntry) {
+ download(fileEntry, url, true);
+
+ }, onErrorCreateFile);
+
+}, onErrorLoadFs);
+```
+
+>*Note* For persistent storage, pass LocalFileSystem.PERSISTENT to
requestFileSystem.
+
+When you have the FileEntry object, download the file using the `download`
method of the FileTransfer object. The 3rd argument to the function is the
success handler, which you can use to call the app's `readBinaryFile` function.
In this code example, the `entry` variable is a new FileEntry object that
receives the result of the download operation.
+
+```
+function download(fileEntry, uri) {
+
+ var fileTransfer = new FileTransfer();
+ var fileURL = fileEntry.toURL();
+
+ fileTransfer.download(
+ uri,
+ fileURL,
+ function (entry) {
+ console.log("download complete: " + entry.toURL());
+ readBinaryFile(entry);
+ },
+ function (error) {
+ console.log("download error source " + error.source);
+ console.log("download error target " + error.target);
+ console.log("upload error code" + error.code);
+ },
+ null, // or, pass false
+ {
+ //headers: {
+ // "Authorization": "Basic
dGVzdHVzZXJuYW1lOnRlc3RwYXNzd29yZA=="
+ //}
+ }
+ );
+}
+```
+
+To support operations with binary files, FileReader supports two methods,
`readAsBinaryString` and `readAsArrayBuffer`. In this example, use
`readAsArrayBuffer` and pass the FileEntry object to the method. Once you read
the file successfully, construct a Blob object using the result of the read.
+
+```
+function readBinaryFile(fileEntry) {
+ fileEntry.file(function (file) {
+ var reader = new FileReader();
+
+ reader.onloadend = function (e) {
+
+ console.log("Successful file read: " + this.result);
+ displayFileData(fileEntry.fullPath + ": " + this.result);
+
+ var blob = new Blob([new Uint8Array(this.result)], { type:
"image/png" });
+ displayImageData(blob);
+ };
+
+ reader.readAsArrayBuffer(file);
+
+ }, onErrorReadFile);
+}
+```
+
+Once you read the file successfully, create a DOM URL string using
`createObjectURL`, and then display the image.
+
+```
+function displayImageData(blob) {
+
+ // Note: Use window.URL.revokeObjectURL when finished with image.
+ var objURL = window.URL.createObjectURL(blob);
+
+ // Displays image if result is a valid DOM string for an image.
+ var elem = document.getElementById('imageFile');
+ elem.src = objURL;
+}
+```
+
+## Upload a File
+
+When you upload a File using the File-Transfer plugin, use the File plugin
to provide files for upload (again, they must be FileEntry objects). Before you
can upload anything, create a file for upload using the `getFile` method of
DirectoryEntry. In this example, create the file in the application's cache
(fs.root). Then call the app's writeFile function so you have some content to
upload.
+
+```
+function onUploadFile() {
+ window.requestFileSystem(window.TEMPORARY, 5 * 1024 * 1024, function
(fs) {
+
+ console.log('file system open: ' + fs.name);
+ var fileName = "uploadSource.txt";
+ var dirEntry = fs.root;
+ dirEntry.getFile(fileName, { create: true, exclusive: false },
function (fileEntry) {
+
+ // Write something to the file before uploading it.
+ writeFile(fileEntry);
+
+ }, onErrorCreateFile);
+
+ }, onErrorLoadFs);
+}
+```
+
+In this example, create some simple content, and then call the app's
upload function.
+
+```
+function writeFile(fileEntry, dataObj) {
+ // Create a FileWriter object for our FileEntry (log.txt).
+ fileEntry.createWriter(function (fileWriter) {
+
+ fileWriter.onwriteend = function (e) {
+ console.log("Successful file read...");
--- End diff --
read => write ?
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