Saturday, March 15, 2014

Apache Cordova Project for Mobile Phone App Development


The Command-Line Interface

This guide shows you how to create applications and deploy them to various native mobile platforms using the cordova command-line interface (CLI). This tool allows you to create new projects, build them on different platforms, and run on real devices or within emulators. The CLI is the main tool to use for the cross-platform workflow (See the Overview for a description of the various workflows.) However, you can also use the CLI to initialize project code, after which you use various platforms' SDKs and shell tools for continued development.

Prerequisites

Before running any command-line tools, you need to install SDKs for each platform you wish to target. (See the Platform Guides for more details.)
To add support or rebuild a project for any platform, you need to run the command-line interface from the same machine that supports the platform's SDK. The CLI supports the following combinations:
  • iOS (Mac)
  • Amazon Fire OS (Mac, Linux, Windows)
  • Android (Mac, Linux)
  • BlackBerry 10 (Mac, Linux, Windows)
  • Windows Phone 7 (Windows)
  • Windows Phone 8 (Windows)
  • Windows 8 (Windows)
  • Firefox OS (Mac, Linux, Windows)
On the Mac, the command-line is available via the Terminal application. On the PC, it's available as Command Prompt under Accessories.
The more likely it is that you run the CLI from different machines, the more it makes sense to maintain a remote source code repository, whose assets you pull down to local working directories.
To install the cordova command-line tool, follow these steps:
  1. Download and install Node.js. Following installation, you should be able to invoke node or npm on your command line.
  2. Install the cordova utility. In Unix, prefixing the additional sudo command may be necessary to install development utilities in otherwise restricted directories:
    $ sudo npm install -g cordova
    The installation log may produce errors for any uninstalled platform SDKs. Following installation, you should be able to run cordova on the command line.
    NOTE: The -g flag above tells npm to install cordova globally. You may need to add the npm directory to your PATH in order to invoke globally installed npm modules. On Windows, npm can usually be found at C:\Users\username\AppData\Roaming\npm and on Unix at /usr/local/share/npm.

Create the App

Go to the directory where you maintain your source code, and run a command such as the following:
    $ cordova create hello com.example.hello HelloWorld
It may take some time for the command to complete, so be patient. Running the command with the -d option displays information about its progress.
The first argument hello specifies a directory to be generated for your project. This directory should not already exist, Cordova will create it for you. Its www subdirectory houses your application's home page, along with various resources under css, js, and img, which follow common web development file-naming conventions. The config.xml file contains important metadata needed to generate and distribute the application.
The second argument com.example.hello provides your project with a reverse domain-style identifier. This argument is optional, but only if you also omit the third argument, since the arguments are positional. You can edit this value later in the config.xml file, but do be aware that there may be code generated outside of config.xml using this value, such as Java package names. The default value is io.cordova.hellocordova, but it is recommended that you select an appropriate value.
The third argument HelloWorld provides the application's display title. This argument is optional. You can edit this value later in the config.xml file, but do be aware that there may be code generated outside of config.xml using this value, such as Java class names. The default value is HelloCordova, but it is recommended that you select an appropriate value.

Add Platforms

All subsequent commands need to be run within the project's directory, or any subdirectories within its scope:
    $ cd hello
Before you can build the project, you need to specify a set of target platforms. Your ability to run these commands depends on whether your machine supports each SDK, and whether you have already installed each SDK. Run any of these from a Mac:
    $ cordova platform add ios
    $ cordova platform add amazon-fireos
    $ cordova platform add android
    $ cordova platform add blackberry10
    $ cordova platform add firefoxos
Run any of these from a Windows machine, where wp refers to different versions of the Windows Phone operating system:
    $ cordova platform add wp7
    $ cordova platform add wp8
    $ cordova platform add windows8
    $ cordova platform add amazon-fireos
    $ cordova platform add android
    $ cordova platform add blackberry10
    $ cordova platform add firefoxos
Run this to check your current set of platforms:
    $ cordova platforms ls
(Note the platform and platforms commands are synonymous.)
Run either of the following synonymous commands to remove a platform:
    $ cordova platform remove blackberry10
    $ cordova platform rm amazon-fireos
    $ cordova platform rm android
Running commands to add or remove platforms affects the contents of the project's platforms directory, where each specified platform appears as a subdirectory. The www source directory is reproduced within each platform's subdirectory, appearing for example in platforms/ios/www or platforms/android/assets/www. Because the CLI constantly copies over files from the source www folder, you should only edit these files and not the ones located under the platforms subdirectories. If you use version control software, you should add this source www folder, along with the merges folder, to your version control system. (More information about the merges folder can be found in the Customize Each Platform section below.)
WARNING: When using the CLI to build your application, you are strongly discouraged from editing any files in the /platforms/ folder unless you know what you are doing or are specifically told otherwise in documentation. This is because the files in the /platforms/ directory will be overwritten on prepare or plugin reinstallation.
If you wish at this point, you can use an SDK such as Eclipse or Xcode to open the project you created. You will need to open the derivative set of assets from the /platforms/ directory to develop with an SDK. This is because the SDK specific metadata files are stored within the appropriate /platform/ subdirectory. (See the Platform Guides for information on how to develop applications within each IDE.) Use this approach if you simply want to initialize a project using the CLI and then switch to an SDK for native work.
Read on if you wish to use the cross-platform workflow approach (the CLI) for the entire development cycle.

Build the App

By default, the cordova create script generates a skeletal web-based application whose home page is the project's www/index.html file. Edit this application however you want, but any initialization should be specified as part of the deviceready event handler, referenced by default from www/js/index.js.
Run the following command to iteratively build the project:
    $ cordova build
This generates platform-specific code within the project's platforms subdirectory. You can optionally limit the scope of each build to specific platforms:
    $ cordova build ios
The cordova build command is a shorthand for the following, which in this example is also targeted to a single platform:
    $ cordova prepare ios
    $ cordova compile ios
In this case, once you run prepare, you can use Apple's Xcode SDK as an alternative to modify and compile the platform-specific code that Cordova generates within platforms/ios. You can use the same approachhttp://cordova.apache.org/docs/en/3.4.0guide_cli_index.md.html#The%20Command-Line%20Interface_prerequisites

Test the App on an Emulator or Device

SDKs for mobile platforms often come bundled with emulators that execute a device image, so that you can launch the app from the home screen and see how it interacts with many platform features. Run a command such as the following to rebuild the app and view it within a specific platform's emulator:
    $ cordova emulate android
Some mobile platforms emulate a particular device by default, such as the iPhone for iOS projects. For other platforms, you may need to first associate a device with an emulator.
Note: Emulator support is currently not available for Amazon Fire OS
(See the Platform Guides for details.) For example, you may first run the android command to launch the Android SDK, then run a particular device image, which launches it according to its default behavior:

Following up with the cordova emulate command refreshes the emulator image to display the latest application, which is now available for launch from the home screen:

Alternately, you can plug the handset into your computer and test the app directly:
    $ cordova run android
Before running this command, you need to set up the device for testing, following procedures that vary for each platform. In Android and Amazon Fire OS devices, you would have to enable a USB debugging option on the device, and perhaps add a USB driver depending on your development environmnent. See Platform Guides for details on each platform's requirements.

Add Plugin Features

When you build and view a new project, the default application that appears doesn't do very much. You can modify the app in many ways to take advantage of standard web technologies, but for the app to communicate closely with various device-level features, you need to add plugins that provide access to core Cordova APIs.
A plugin is a bit of add-on code that provides an interface to native components. You can design your own plugin interface, for example when designing a hybrid app that mixes a Cordova WebView with native components. (See Embedding WebViews and Plugin Development Guide for details.) More commonly, you would add a plugin to enable one of Cordova's basic device-level features detailed in the API Reference. A list of these plugins, including additional plugins provided by the community, can be found at plugins.cordova.io. You can use the CLI to search for plugins from this registry. For example, searching for bar and code produces a single result that matches both terms as case-insensitive substrings:
    $ cordova plugin search bar code

    com.phonegap.plugins.barcodescanner - Scans Barcodes
Searching for only the bar term yields and additional result:
    org.apache.cordova.statusbar - Cordova StatusBar Plugin
The cordova plugin add command requires you to specify the repository for the plugin code. Please note that when you follow the Web Project Dev workflow and use the CLI, the CLI will take care of adding the plugin code to the appropriate place for each platform. (If you are following the Native Project Dev Workflow, you will have to add plugins using Plugman (guide link here), multiple times for each platform.)
Here are examples of how you might use the CLI to add features to the app:
  • Basic device information (Device API):
    $ cordova plugin add org.apache.cordova.device
  • Network Connection and Battery Events:
    $ cordova plugin add org.apache.cordova.network-information
    $ cordova plugin add org.apache.cordova.battery-status
  • Accelerometer, Compass, and Geolocation:
    $ cordova plugin add org.apache.cordova.device-motion
    $ cordova plugin add org.apache.cordova.device-orientation
    $ cordova plugin add org.apache.cordova.geolocation
  • Camera, Media playback and Capture:
    $ cordova plugin add org.apache.cordova.camera
    $ cordova plugin add org.apache.cordova.media-capture
    $ cordova plugin add org.apache.cordova.media
  • Access files on device or network (File API):
    $ cordova plugin add org.apache.cordova.file
    $ cordova plugin add org.apache.cordova.file-transfer
  • Notification via dialog box or vibration:
    $ cordova plugin add org.apache.cordova.dialogs
    $ cordova plugin add org.apache.cordova.vibration
  • Contacts:
    $ cordova plugin add org.apache.cordova.contacts
  • Globalization:
    $ cordova plugin add org.apache.cordova.globalization
  • Splashscreen:
    $ cordova plugin add org.apache.cordova.splashscreen
  • Open new browser windows (InAppBrowser):
    $ cordova plugin add org.apache.cordova.inappbrowser
  • Debug console:
    $ cordova plugin add org.apache.cordova.console
Use plugin ls (or plugin list, or plugin by itself) to view currently installed plugins. Each displays by its identifier:
    $ cordova plugin ls    # or 'plugin list'
    [ 'org.apache.cordova.console' ]
To remove a plugin, refer to it by the same identifier that appears in the listing. For example, here is how you would remove support for a debug console from a release version:
    $ cordova plugin rm org.apache.cordova.console
    $ cordova plugin remove org.apache.cordova.console    # same
You can batch-remove or add plugins by specifying more than one argument for each command:
    $ cordova plugin add org.apache.cordova.console org.apache.cordova.device

Advanced Plugin Options

When adding a plugin, several options allow you to specify from where to fetch the plugin. The examples above use a well-known registry.cordova.io registry, and the plugin is specified by the id:
    $ cordova plugin add org.apache.cordova.console
The id may also include the plugin's version number, appended after an @ character. The latest version is an alias for the most recent version. For example:
    $ cordova plugin add org.apache.cordova.console@latest
    $ cordova plugin add org.apache.cordova.console@0.2.1
If the plugin is not registered at registry.cordova.io but is located in another git repository, you can specify an alternate URL:
    $ cordova plugin add https://github.com/apache/cordova-plugin-console.git
The git example above fetches the plugin from the end of the master branch, but an alternate git-ref such as a tag or branch can be appended after a # character:
    $ cordova plugin add https://github.com/apache/cordova-plugin-console.git#r0.2.0
If the plugin (and its plugin.xml file) is in a subdirectory within the git repo, you can specify it with a : character. Note that the # character is still needed:
    $ cordova plugin add https://github.com/someone/aplugin.git#:/my/sub/dir
You can also combine both the git-ref and the subdirectory:
    $ cordova plugin add https://github.com/someone/aplugin.git#r0.0.1:/my/sub/dir
Alternately, specify a local path to the plugin directory that contains the plugin.xml file:
    $ cordova plugin add ../my_plugin_dir

Using merges to Customize Each Platform

While Cordova allows you to easily deploy an app for many different platforms, sometimes you need to add customizations. In that case, you don't want to modify the source files in various www directories within the top-level platforms directory, because they're regularly replaced with the top-level www directory's cross-platform source.
Instead, the top-level merges directory offers a place to specify assets to deploy on specific platforms. Each platform-specific subdirectory within merges mirrors the directory structure of the www source tree, allowing you to override or add files as needed. For example, here is how you might uses merges to boost the default font size for Android and Amazon Fire OS devices:
  • Edit the www/index.html file, adding a link to an additional CSS file, overrides.css in this case:
    <link rel="stylesheet" type="text/css" href="css/overrides.css" />
    
  • Optionally create an empty www/css/overrides.css file, which would apply for all non-Android builds, preventing a missing-file error.
  • Create a css subdirectory within merges/android, then add a corresponding overrides.css file. Specify CSS that overrides the 12-point default font size specified within www/css/index.css, for example:
    body { font-size:14px; }
    
When you rebuild the project, the Android version features the custom font size, while others remain unchanged.
You can also use merges to add files not present in the original www directory. For example, an app can incorporate a back button graphic into the iOS interface, stored in merges/ios/img/back_button.png, while the Android version can instead capture backbutton events from the corresponding hardware button.

Help Commands

Cordova features a couple of global commands, which may help you if you get stuck or experience a problem. The help command displays all available Cordova commands and their syntax:
$ cordova help
$ cordova        # same
The info command produces a listing of potentially useful details, such as currently installed platforms and plugins, SDK versions for each platform, and versions of the CLI and node.js:
$ cordova info
It both presents the information to screen and captures the output in a local info.txt file.
NOTE: Currently, only details on iOS and Android platforms are available.

Updating Cordova and Your Project

After installing the cordova utility, you can always update it to the latest version by running the following command:
    $ sudo npm update -g cordova
Use this syntax to install a specific version:
    $ sudo npm install -g cordova@3.1.0-0.2.0
Run cordova -v to see which version is currently running. Run the npm info command for a longer listing that includes the current version along with other available version numbers:
    $ npm info cordova
Cordova 3.0 is the first version to support the command-line interface described in this section. If you are updating from a version prior to 3.0, you need to create a new project as described above, then copy the older application's assets into the top-level www directory. Where applicable, further details about upgrading to 3.0 are available in the Platform Guides. Once you upgrade to the cordova command-line interface and use npm update to stay current, the more time-consuming procedures described there are no longer relevant.
Cordova 3.0+ may still require various changes to project-level directory structures and other dependencies. After you run the npm command above to update Cordova itself, you may need to ensure your project's resources conform to the latest version's requirements. Run a command such as the following for each platform you're building:
    $ cordova platform update android
    $ cordova platform update ios
    ...etc.
 
 
Original link: 
http://cordova.apache.org/docs/en/3.4.0/guide_cli_index.md.html#The%20Command-Line%20Interface_prerequisites 

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