cordova-plugin-network-information

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This plugin provides an implementation of an old version of the Network Information API. It provides information about the device's cellular and wifi connection, and whether the device has an internet connection.

To get a few ideas how to use the plugin, check out the sample at the bottom of this page or go straight to the reference content.

Installation

cordova plugin add cordova-plugin-network-information

Supported Platforms

  • Android
  • Browser
  • iOS
  • Windows

Connection

The connection object, exposed via navigator.connection, provides information about the device's cellular and wifi connection.

Properties

  • connection.type

Constants

  • Connection.UNKNOWN
  • Connection.ETHERNET
  • Connection.WIFI
  • Connection.CELL_2G
  • Connection.CELL_3G
  • Connection.CELL_4G
  • Connection.CELL
  • Connection.NONE

connection.type

This property offers a fast way to determine the device's network connection state, and type of connection.

Quick Example

function checkConnection() {
    var networkState = navigator.connection.type;

    var states = {};
    states[Connection.UNKNOWN]  = 'Unknown connection';
    states[Connection.ETHERNET] = 'Ethernet connection';
    states[Connection.WIFI]     = 'WiFi connection';
    states[Connection.CELL_2G]  = 'Cell 2G connection';
    states[Connection.CELL_3G]  = 'Cell 3G connection';
    states[Connection.CELL_4G]  = 'Cell 4G connection';
    states[Connection.CELL]     = 'Cell generic connection';
    states[Connection.NONE]     = 'No network connection';

    alert('Connection type: ' + states[networkState]);
}

checkConnection();

iOS Quirks

  • <iOS7 can't detect the type of cellular network connection.
    • navigator.connection.type is set to Connection.CELL for all cellular data.

Windows Quirks

  • When running in the Phone 8.1 emulator, always detects navigator.connection.type as Connection.ETHERNET.

Browser Quirks

  • Browser can't detect the type of network connection. navigator.connection.type is always set to Connection.UNKNOWN when online.

Network-related Events

offline

The event fires when an application goes offline, and the device is not connected to the Internet.

document.addEventListener("offline", yourCallbackFunction, false);

Details

The offline event fires when a previously connected device loses a network connection so that an application can no longer access the Internet. It relies on the same information as the Connection API, and fires when the value of connection.type becomes NONE.

Applications typically should use document.addEventListener to attach an event listener once the deviceready event fires.

Quick Example

document.addEventListener("offline", onOffline, false);

function onOffline() {
    // Handle the offline event
}

Quirks

This plugin is unable to broadcast events while in the background. Use navigator.connection.type to check connection status on the resume event instead.

iOS Quirks

During initial startup, the first offline event (if applicable) takes at least a second to fire.

online

This event fires when an application goes online, and the device becomes connected to the Internet.

document.addEventListener("online", yourCallbackFunction, false);

Details

The online event fires when a previously unconnected device receives a network connection to allow an application access to the Internet. It relies on the same information as the Connection API, and fires when the connection.type changes from NONE to any other value.

Applications typically should use document.addEventListener to attach an event listener once the deviceready event fires.

Quick Example

document.addEventListener("online", onOnline, false);

function onOnline() {
    // Handle the online event
}

Quirks

This plugin is unable to broadcast events while in the background. Use navigator.connection.type to check connection status on the resume event instead.

iOS Quirks

During initial startup, the first online event (if applicable) takes at least a second to fire, prior to which connection.type is UNKNOWN.

Sample: Upload a File Depending on your Network State

The code examples in this section show examples of changing app behavior using the online and offline events and your network connection status.

To start with, create a new FileEntry object (data.txt) to use for sample data. Call this function from the deviceready handler.

Note This code example requires the File plugin.

var dataFileEntry;

function createSomeData() {

    window.requestFileSystem(window.TEMPORARY, 5 * 1024 * 1024, function (fs) {

        console.log('file system open: ' + fs.name);
        // Creates a new file or returns an existing file.
        fs.root.getFile("data.txt", { create: true, exclusive: false }, function (fileEntry) {

          dataFileEntry = fileEntry;

        }, onErrorCreateFile);

    }, onErrorLoadFs);
}

Next, add listeners for the online and offline events in the deviceready handler.

document.addEventListener("offline", onOffline, false);
document.addEventListener("online", onOnline, false);

The app's onOnline function handles the online event. In the event handler, check the current network state. In this app, treat any connection type as good except Connection.NONE. If you have a connection, you try to upload a file.

function onOnline() {
    // Handle the online event
    var networkState = navigator.connection.type;

    if (networkState !== Connection.NONE) {
        if (dataFileEntry) {
            tryToUploadFile();
        }
    }
    display('Connection type: ' + networkState);
}

When the online event fires in the preceding code, call the app's tryToUploadFile function.

If the upload fails, then call the app's offlineWrite function to save the current data somewhere.

Note For simplicity, file reading & writing was omitted. Refer to the cordova-plugin-file documentation for more information on file handling.

function tryToUploadFile() {
    // !! Assumes variable fileURL contains a valid URL to a text file on the device,
    var fileURL = getDataFileEntry().toURL();
    
    getFileBlobSomehow(fileURL, function(fileBlob) {
        var success = function (r) {
            console.log("Response = " + r.response);
            display("Uploaded. Response: " + r.response);
        };

        var fail = function (error) {
            console.log("An error has occurred: Code = " + error.code || error.status);
            offlineWrite("Failed to upload: some offline data");
        }

        var xhr = new XMLHttpRequest();

        xhr.onerror = fail;
        xhr.ontimeout = fail;
        xhr.onload = function() {
            // If the response code was successful...
            if (xhr.status >= 200 && xhr.status < 400) {
                success(xhr);
            }
            else {
                fail(xhr)
            }
        }

        // Make sure you add the domain of your server URL to the
        // Content-Security-Policy <meta> element in index.html.
        xhr.open("POST", encodeURI(SERVER));

        xhr.setRequestHeader("Content-Type", "text/plain");

        // The server request handler could read this header to
        // set the filename.
        xhr.setRequestHeader("X-Filename", fileURL.substr(fileURL.lastIndexOf("/") + 1));

        xhr.send(fileBlob);
    });
};

Here is the code for the offlineWrite function.

Note This code examples requires the File plugin.

function offlineWrite(offlineData) {
    // Create a FileWriter object for our FileEntry.
    dataFileEntry.createWriter(function (fileWriter) {

        fileWriter.onwriteend = function () {
            console.log("Successful file write...");
            display(offlineData);
        };

        fileWriter.onerror = function (e) {
            console.log("Failed file write: " + e.toString());
        };

        fileWriter.write(offlineData);
    });
}

If the offline event occurs, just do something like notify the user (for this example, just log it).

function onOffline() {
    // Handle the offline event
    console.log("lost connection");
}