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@nativescript/background-http

npm install @nativescript/background-http

Usage

The below attached code snippets demonstrate how to use @nativescript/background-http to upload single or multiple files.

Note

Call init before the app starts to initialize the http background service

import { init } from '@nativescript/background-http'
init()

Uploading files

Sample code for configuring the upload session. Each session must have a unique id, but it can have multiple tasks running simultaneously. The id is passed as a parameter when creating the session (the image-upload string in the code below):

// file path and url
var file = '/some/local/file/path/and/file/name.jpg'
var url = 'https://some.remote.service.com/path'
var name = file.substr(file.lastIndexOf('/') + 1)

// upload configuration
var bghttp = require('@nativescript/background-http')
var session = bghttp.session('image-upload')
var request = {
  url: url,
  method: 'POST',
  headers: {
    'Content-Type': 'application/octet-stream'
  },
  description: 'Uploading ' + name
}

For a single file upload, use the following code:

var task = session.uploadFile(file, request);

For multiple files or to pass additional data, use the multipart upload method. All parameter values must be strings:

var params = [
   { name: "test", value: "value" },
   { name: "fileToUpload", filename: file, mimeType: "image/jpeg" }
];
var task = session.multipartUpload(params, request);

In order to have a successful upload, the following must be taken into account:

  • the file must be accessible from your app. This may require additional permissions (e.g. access documents and files on the device). Usually this is not a problem - e.g. if you use another plugin to select the file, which already adds the required permissions.
  • the URL must not be blocked by the OS. Android Pie or later devices require TLS (HTTPS) connection by default and will not upload to an insecure (HTTP) URL.

Upload request and task API

The request object parameter has the following properties:

NameTypeDescription
urlstringThe request url (e.g.https://some.remote.service.com/path).
methodstringThe request method (e.g. POST).
headersobjectUsed to specify additional headers.
descriptionstringUsed to help identify the upload task locally - not sent to the remote server.
utf8boolean(Android only/multipart only) If true, sets the charset for the multipart request to UTF-8. Default is false.
androidNotificationOnProgressTitlestringUse this to set the on progress title shown in the Android notifications center.
androidNotificationOnProgressMessagestringUse this to set the on progress message shown in the Android notifications center.
androidNotificationOnCompleteTitlestringUse this to set the on complete message shown in the Android notifications center.
androidNotificationOnCompleteMessagestringUse this to set the on error title shown in the Android notifications center.
androidNotificationOnErrorTitlestringUse this to set the on error title shown in the Android notifications center.
androidNotificationOnErrorMessagestringUse this to set the on error message shown in the Android notifications center.
androidNotificationOnCancelledTitlestringUse this to set the on cancelled title shown in the Android notifications center.
androidNotificationOnCancelledMessagestringUse this to set the on cancelled message shown in the Android notifications center.
androidAutoDeleteAfterUploadboolean(Android only) Used to set if files should be deleted automatically after upload.
androidMaxRetriesnumber(Android only) Used to set the maximum retry count. The default retry count is 0. https://github.com/gotev/android-upload-service/wiki/Recipes#backoff
androidAutoClearNotificationboolean(Android only) Used to set if notifications should be cleared automatically upon upload completion. Default is false. Please note that setting this to true will also disable the ringtones.
androidRingToneEnabledboolean(Android only) Used to set if a ringtone should be played upon upload completion. Default is true. Please note that this flag has no effect when androidAutoClearNotification is set to true.
androidNotificationChannelIDstring(Android only) Used to set the channel ID for the notifications.

Note :- Android Notification titles/messages can be constructed with one of the following placeholder which will be replaced by the system .

Replaced with the current upload rate/speed [upload_rate]

Replaced with the current upload progress [upload_progress]

Replaced with the elapsed time [upload_elapsed_time]

The task object has the following properties and methods, that can be used to get information about the upload:

NameTypeDescription
uploadnumberBytes uploaded.
totalUploadnumberTotal number of bytes to upload.
statusstringOne of the following: error, uploading, complete, pending, cancelled.
descriptionstringThe description set in the request used to create the upload task.
cancel()voidCall this method to cancel an upload in progress.

Handling upload events

After the upload task is created you can monitor its progress using the following events:

task.on("progress", progressHandler);
task.on("error", errorHandler);
task.on("responded", respondedHandler);
task.on("complete", completeHandler);
task.on("cancelled", cancelledHandler); // Android only

Each event handler will receive a single parameter with event arguments:

// event arguments:
// task: Task
// currentBytes: number
// totalBytes: number
function progressHandler(e) {
    alert("uploaded " + e.currentBytes + " / " + e.totalBytes);
}

// event arguments:
// task: Task
// responseCode: number
// error: java.lang.Exception (Android) / NSError (iOS)
// response: net.gotev.uploadservice.ServerResponse (Android) / NSHTTPURLResponse (iOS)
function errorHandler(e) {
    alert("received " + e.responseCode + " code.");
    var serverResponse = e.response;
}


// event arguments:
// task: Task
// responseCode: number
// data: string
function respondedHandler(e) {
    alert("received " + e.responseCode + " code. Server sent: " + e.data);
}

// event arguments:
// task: Task
// responseCode: number
// response: net.gotev.uploadservice.ServerResponse (Android) / NSHTTPURLResponse (iOS)
function completeHandler(e) {
    alert("received " + e.responseCode + " code");
    var serverResponse = e.response;
}

// event arguments:
// task: Task
function cancelledHandler(e) {
    alert("upload cancelled");
}

Testing the plugin

In order to test the plugin, you must have a server instance to accept the uploads. There are online services that can be used for small file uploads - e.g. http://httpbin.org/post However, these cannot be used for large files. The plugin repository comes with a simple server you can run locally. Here is how to start it:

cd demo-server
npm i
node server 8080

The above commands will start a server listening on port 8080. Remember to update the URL in your app to match the address/port where the server is running.

Note

If you are using the iOS simulator then http://localhost:8080 should be used to upload to the demo server. If you are using an Android emulator, http://10.0.2.2:8080 should be used instead.

License

Apache License Version 2.0