Ext JS 4.2.0 Sencha Docs

Introduction to Sencha Cmd

Sencha Cmd is a cross-platform command line tool that provides many automated tasks around the full life-cycle of your applications from generating a new project to deploying an application to production.

Sencha Cmd provides a collection of powerful time-saving features that work together and in conjunction with the Sencha Ext JS and Sencha Touch frameworks. Sencha Cmd provides the following capabilities:

  • Code Generation Tools: Code generation tools to generate entire applications and extend those applications with new MVC components.
  • JS Compiler: A framework-aware, JavaScript compiler that knows the semantics of Sencha frameworks and can produce minimal footprint builds from your source. In the future, the compiler will optimize many of the high-level semantics provided by Sencha frameworks to reduce load time of your applications.
  • Web Server: Provides a lightweight web server that serves files from localhost.
  • Packaging: Native packaging to convert a Sencha Touch application into a first-class, mobile application that has access to device functionality and can be distributed in App Stores.
  • Management System: Distributed package management system for easy integration of packages (such as Ext JS Themes) created by others or from the Sencha Package Repository.
  • Build Scripts: Generated build script for applications and packages with "before" and "after" extension points so you can customize the build process to fit your specific needs.
  • Tuning Tools: Powerful code selection tools for tuning what is included in your application's final build, determine common code across pages and partition shared code into "packages" - all using high-level set operations to get builds exactly as you want them.
  • Workspace Management: Assists in sharing frameworks, packages and custom code between applications.
  • Image Capture: Converts CSS3 features (such as border-radius and linear-gradient) into sprites for legacy browsers.
  • Flexible Configuration System: Enables defaults to be specified for command options at the application or workspace level or across all workspaces on a machine.
  • Logging: Robust logging to help you understand the inner workings of commands and facilitate troubleshooting.
  • Third-party Software: Sencha Cmd includes a compatible version of Compass, Sass, and Apache Ant.
  • Code Generation Hooks: Can be specific to one page or shared by all pages in the workspace, for example, to check coding conventions or guidelines as new models are generated).


Sencha Cmd is designed for Sencha Ext JS version 4.1.1a or higher and Sencha Touch version 2.1 or higher. Many of the new features of Sencha Cmd require framework support that is only available at these or later version levels. Some low-level commands can be used for older versions of Sencha frameworks or JavaScript in general.

If you are using an older version of Ext JS, you may use Sencha Cmd's build command to build via your JSB file. In other words, Sencha Cmd can replace JSBuilder to produce a compressed build of the files described in a JSB file. Sencha Cmd will not update your JSB file as was done by the previous SDK Tools v2.

Sencha Touch 2.0 and Sencha Ext JS 4.0 require SDK Tools v2; however SDK Tools are deprecated for use with releases after these.

System Setup

Follow these steps to set up your system and start using Sencha Cmd:

  1. Download and install a Java Run-time Environment or JRE. It is best to download the most up-to-date version available. The JRE version must be at least JRE 6, JRE 7 is best.
  2. Download and install Sencha Cmd.
  3. Download the appropriate version of the Ext JS SDK for desktop applications or Sencha Touch for mobile applications.
  4. Extract the SDK to a local directory.

Compass and Sass Setup

Sencha Cmd includes compatible versions of Compass and Sass that you can use to develop CSS content using Sass. To get Compass and Sass working on your computer, you need to install Ruby version 1.9.3 (Ruby version 2.0 is not supported):

  • Windows: Download Ruby 1.9.3 from rubyinstaller.org. Download the RubyInstaller .exe file and run it.

  • Mac OS: Ruby is pre-installed. You can test which version you have with the ruby -v command. If you have version 2.0, download the Ruby version manager (rvm) and use this command to download and install Ruby: rvm install 1.9.3 --with-gcc=clang

    Set your PATH variable to point to the Ruby 1.9.3 install directory.

  • Ubuntu: Use sudo apt-get install ruby1.9.3 to download and install Ruby 1.9.3.

Verify Installation

To verify that Sencha Cmd is working properly, open a command line, change directory to your application, and type the sencha command.

You should see output that starts with:

Sencha Cmd v3.1.n

If this message appears and the version number is 3.1.n or higher, you are all set.

Upgrading Sencha Cmd

The sencha upgrade feature lets you upgrade Sencha Cmd.

Check for new updates to Sencha Cmd:

sencha upgrade --check

Without the --check option, the sencha upgrade command downloads and installs the latest version if you don't already have it:

sencha upgrade

If you want to check for beta releases, use:

sencha upgrade --check --beta

To install the latest beta version:

sencha upgrade --beta

After the installer is done, start a new console or terminal to pick up the changes to your PATH environment variable.

Because multiple versions of Sencha Cmd can be installed side-by-side, you can safely try the Beta channel and then uninstall the beta (or adjust the PATH) to go back to the stable version. Upgrading your applications using sencha upgrade however, is something you may need "roll back" if you downgrade to an older Sencha Cmd.

Note It is possible that the most current release is in either the "beta" or stable channel. That is to say, sencha upgrade --beta may install a beta that predates the current release that would be installed by sencha upgrade.

Command Basics

Sencha Cmd features are arranged in categories (or modules) and commands:

sencha [category] [command] [options...] [arguments...]

Help is available using the help command.

sencha help [module] [action]

For example, try this:

sencha help

And you should see this:

Sencha Cmd v3.1.n

  * --cwd, -cw - Sets the directory from which commands should execute
  * --debug, -d - Sets log level to higher verbosity
  * --nologo, -n - Suppress the initial Sencha Cmd version display
  * --plain, -pl - enables plain logging output (no highlighting)
  * --quiet, -q - Sets log level to warnings and errors only
  * --sdk-path, -s - The location of the SDK to use for non-app commands
  * --time, -ti - Display the execution time after executing all commands

  * app - Perform various application build processes
  * compass - Wraps execution of compass for sass compilation
  * compile - Compile sources to produce concatenated output and metadata
  * fs - Utility commands to work with files
  * generate - Generates models, controllers, etc. or an entire application
  * io - Create, deploy and manage applications on the Sencha.io cloud platform
  * iofs - Manage Files stored in the Sencha.io cloud platform
  * manifest - Extract class metadata
  * package - Manages local and remote packages
  * repository - Manage local repository and remote repository connections
  * theme - Commands for low-level operations on themes

  * ant - Invoke Ant with helpful properties back to Sencha Cmd
  * build - Builds a project from a legacy JSB3 file.
  * config - Load a properties file or sets a configuration property
  * help - Displays help for commands
  * js - Executes arbitrary JavaScript file(s)
  * upgrade - Upgrades Sencha Cmd
  * which - Displays the path to the current version of Sencha Cmd

Current Directory

In many cases, Sencha Cmd requires that you set a specific current directory. Or it may just need to know details about the relevant SDK. The appropriate SDK can be determined automatically by Sencha Cmd when it is run from a generated application folder or, for some few commands, from an extracted SDK folder.

Important For the following commands, Sencha Cmd needs to be run from the root folder of a generated application. The commands fail if not run from the application's root folder.

* `sencha generate ...` (for commands other than `app`, `package` and `workspace`)
* `sencha app ...`

To generate an application, run the following command from an extracted SDK folder:

cd /path/to/SDK
sencha generate app ...

Or you can use the -sdk switch:

sencha -sdk /path/to/sdk generate app ...

When using the compiler, Sencha Cmd detects the framework in use when run from an application folder. If you are not running from a generated application, you may need to use the -sdk switch:

sencha -sdk /path/to/sdk compile ...

Important Do not specify the -sdk parameter for sencha app commands. As noted above, these commands must be run from the application's root folder and therefore automatically know which SDK to use. Using -sdk on these commands causes Sencha Cmd to believe your current directory is the SDK specified which is not the proper current directory for an application.

Developing Applications

The starting point for most projects is to generate an application skeleton. This is done using the following:

sencha -sdk /path/to/sdk generate app MyApp /path/to/MyApp

Ext JS and Sencha Touch applications are structured differently from each other. Further, particularly with Ext JS, applications can be quite large and may contain multiple pages.

To get started building applications using Sencha Cmd, consult the Using Sencha Cmd guide.

Sencha Cmd Web Server

The Sencha Cmd web server lets you serve files from your applications directory. Use this command to start the web server:

sencha fs web [-port 8000] start -map <dir_name>

(You can use any available TCP port number or omit it and use the default.)

To access the Sencha Cmd web server, use:


Beyond The Basics

There are many other details related to using Sencha Cmd that can be helpful. The help command is a great reference, but if you want to walk through all the highlights, consult Advanced Sencha Cmd.


Here are some tips for solving common problems encountered when using Sencha Cmd.

Command Not Found

If running sencha results in the error message sencha: command not found on OSX/Linux or 'sencha' is not recognized as an internal or external command, operable program or batch file on Windows, follow these steps:

  • Close all existing terminal/command prompt windows and reopen them.
  • Make sure that Sencha Cmd is properly installed:
    • The installation directory exists. By default, the installation path is:
      • Windows: C:\Users\Me\bin\Sencha\Cmd\{version}
      • Mac OS X: ~/bin/Sencha/Cmd/{version}
      • Linux: ~/bin/Sencha/Cmd/{version}
    • The path to Sencha Cmd directory is prepended to your PATH environment variable. From the terminal, run echo %PATH% on Windows or echo $PATH on Mac or Linux. The Sencha Cmd directory should be displayed in part of the output. If this is not the case, add it to your PATH manually.
    • The environment variable SENCHA_CMD_{version} is set, with the value being the absolute path to the installation directory mentioned above. For example, if the installed version is 3.1.2, a SENCHA_CMD_3_1_2 must be set. If the output is empty, set the environment variable manually. To check, go to the command prompt (or Terminal) and run:
      • Windows: echo %SENCHA_CMD_3_1_2%
      • Other - echo $SENCHA_CMD_3_1_2

Cannot find Ruby

If you see an error related to not recognizing or finding "ruby" this is likely because Ruby is not installed or is not in your PATH. See the previous System Requirements section.

Wrong Current Directory

A common mistake is to perform a command that requires the current directory to be either an extracted SDK directory or an application directory, but such a directory has not been set. If this requirement is not met, Sencha Cmd displays an error and exits.

Note that a valid application directory is one that was generated by Sencha Cmd.

Errors While Resolving Dependencies

The sencha app build command works by reading your index.html and scanning for required classes. If your application does not properly declare the classes it requires, the build usually completes but will not contain all the classes needed by your application.

To ensure that you have all required classes specified, always develop with the debugger console enabled ("Developer Tools" in IE/Chrome, FireBug in FireFox and Web Inspector in Safari) and resolve all warnings and error messages as they appear.

Whenever you see a warning like this:

[Ext.Loader] Synchronously loading 'Ext.foo.Bar'; consider adding 'Ext.foo.Bar' explicitly as a require of the corresponding class

Immediately add 'Ext.foo.Bar' inside the requires array property of the class from which the dependency originates. If it is a application-wide dependency, add it to the requires array property inside Ext.application(...) statement.