PyCharm 2023.3 Help

Dart

With PyCharm, you can develop, run, and debug Dart web and command-line applications. PyCharm helps you provide code completion, error and syntax highlighting, code inspections and quick-fixes, search and navigation, refactoring, and much more. PyCharm also integrates with the pub tool and the Dart Analysis Server.

Install the Dart plugin

This functionality relies on the Dart plugin, which you need to install and enable.

  1. Press Ctrl+Alt+S to open the IDE settings and then select Plugins.

  2. Open the Marketplace tab, find the Dart plugin, and click Install (restart the IDE if prompted).

Downloading the Dart tools

Download and install the Dart SDK.

The Dart SDK contains all the tools for developing both command-line and web Dart applications. It incorporates the Dart Virtual Machine, the Dart core Libraries, as well as all the command-line tools, including compilers (dart2js and dartdevc), the dartfmt code formatter, and the pub tool.

Learn more about the Dart development tools from the Dart official website.

Creating a new Dart application

If you have no application yet, you can generate a PyCharm project with Dart-specific structure by running the dart create command.

Alternatively, create an empty PyCharm project and configure Dart support in it as described in Starting with an existing Dart application below.

Create a new Dart project

  1. Click Create New Project on the Welcome screen or select File | New | Project from the main menu. The New Project dialog opens.

  2. In the left-hand pane, choose Dart.

  3. In the right-hand pane, specify The path to the folder where the project-related files will be stored.

  4. Specify the location of the downloaded Dart SDK.

    If you followed the standard installation procedure, as described on the Dart official website, PyCharm detects the path to the Dart SDK automatically.

    Alternatively, type the path manually or click the Browse button and select the path in the dialog that opens.

    If PyCharm recognizes the Dart SDK correctly, its revision number is displayed in the Version read-only field.

  5. To have a sample application created in the project, select the Generate sample content checkbox and choose the relevant template from the list below. If you clear the checkbox, PyCharm creates an empty project.

  6. Click Create. PyCharm sets up the project structure and generates some sources based on the selected template.

Create an empty PyCharm project

  1. Click Create New Project on the Welcome screen or select File | New | Project from the main menu. The New Project dialog opens.

  2. In the left-hand pane, choose Empty Project. In the right-hand pane, specify the application folder and click Create.

Starting with an existing Dart application

If you are going to continue developing an existing Dart application, open it in PyCharm, configure Dart in it, and download the required dependencies as described in Managing Dart dependencies below.

Open the application sources that are already on your machine

Click Open on the Welcome screen or select File | Open from the main menu. In the dialog that opens, select the folder where your sources are stored.

    Check out the application sources from your version control

    1. Click Get from VCS on the Welcome screen.

      Alternatively, select File | New | Project from Version Control or Git | Clone or VCS | Get from Version Control from the main menu.

      Instead of Git in the main menu, you may see any other Version Control System that is associated with your project. For example, Mercurial or Perforce.

    2. In the dialog that opens, select your version control system from the list and specify the repository to check out the application sources from. For more information, refer to Check out a project (clone).

    Configure Dart support in an existing project

    1. In Settings dialog Ctrl+Alt+S, choose Dart under Languages and Frameworks. The Dart page opens.

    2. Select the Enable Dart support for the project <project name> checkbox.

    3. In the Dart SDK Path field, specify the location of the downloaded Dart SDK.

      If you followed the standard installation procedure, as described on the Dart official website, PyCharm detects the path to the Dart SDK automatically.

      Alternatively, type the path manually or click the Browse button and select the path in the dialog that opens.

      If PyCharm recognizes the Dart SDK correctly, its revision number is displayed in the Version read-only field.

    Working with several Dart projects (packages) in one PyCharm project

    To attach a Dart project (package) to an existing PyCharm project you need to add its root folder as a content root.

    Add a Dart project (package) to an existing PyCharm project

    1. In the Settings dialog (Ctrl+Alt+S) , go to Project Structure. The Project Structure page opens.

    2. In the right-hand pane with a list of existing content roots, click Add Content Root. Then in the dialog that opens, choose the root folder of the Dart project (package) to be attached.

    Managing Dart dependencies

    PyCharm integrates with the pub tool and lets you run its actions right from the editor. As soon as you open a pubspec.yaml file, PyCharm displays a pane at the top of its editor tab. Use the links on this pane to invoke pub get, pub upgrade, and pub outdated actions.

    Dart: pub actions pane

    Alternatively open pubspec.yaml in the editor or select it in the Project tool window and invoke pub actions from the context menu of the selection.

    You can also use the tool in the command-line mode from the Terminal emulator.

    The pub tool saves the downloaded packages in the cache and creates a .packages file and a pubspec.lock file next to the pubspec.yaml file.

    PyCharm logs execution of pub commands in the Messages tool window where you can also re-run the last executed command by clicking Rerun Pub Command on the toolbar.

    Building a Dart application

    1. Open the pubspec.yaml file in the editor or switch to the tab where it is opened.

    2. On the pane at the top of the tab, click Webdev build.... This invokes the webdev build action.

      Dart actions pane: Webdev build

    3. In the dialog that opens, specify the input folder to take the sources from and the output folder where you want the compiled application stored.

    Running and debugging Dart command-line applications

    With PyCharm, you can run and debug Dart command-line applications. PyCharm supports two debugging modes:

    • Local debugging: in this mode, your application is started from PyCharm and is running locally on your computer. To run or debug it, use a Dart Command Line App configuration.

    • Debugging a remote application: in this mode, your application is running in a remote environment, for example, in a Docker container. To debug it, use a Dart Remote Debug configuration.

    Run a Dart command-line application

    1. Open the Dart file to start the application from or select it in the Project tool window. This file must contain a main() method.

    2. From the context menu of the selection, choose Run '<dart_file_name>'. PyCharm generates a run/debug configuration of the type Dart Command Line App and launches your application with it.

    Debug a Dart command-line application locally

    1. Configure and set breakpoints in the Dart code.

    2. Open the Dart file to start the application from or select it in the Project tool window. This file must contain a main() method.

    3. From the context menu of the selection, choose Debug '<dart_file_name>'. PyCharm generates a run/debug configuration of the type Dart Command Line App and starts a debugging session with it.

    4. In the Debug tool window that opens, step through the program, stop and resume program execution, examine it when suspended, and so on.

    Create a Dart Remote Debug run/debug configuration

    1. Select Edit Configurations from the Run/Debug Configurations widget on the toolbar, click the Add New Configuration button (the Add New Configuration button) and select Dart Remote Debug from the list to open the configuration settings.

      Start creating a run/debug configuration

    2. In the Search Sources in field, specify the Dart project to debug if your PyCharm project contains several Dart projects configured as content roots. Select the Dart project from the list or click the Browse button and select the required folder in the dialog that opens.

    Launch a remote debugging session

    1. Start a remote Dart application with the VM options, for example, with --enable-vm-service --pause_isolates_on_start. The application starts, immediately suspends thanks to the --pause_isolates_on_start argument, and waits for the debugger to connect.

    2. In the Run tool window, copy the URL address at which the application is running and the generated authentication token to access it.

      Dart: remote debugging. Copy URL and token

    3. Choose the newly created Dart Remote Debug configuration in the Select run/debug configuration list and click the Debug button.

    4. In the Connect to a Running App dialog, paste the URL address and the authentication token you copied as described above.

      Dart: remote debugging. Paste URL and token

    5. In the Debug tool window that opens, step through the program, stop and resume program execution, examine it when suspended, and so on.

    Running and debugging Dart web applications

    You can run a Dart web application in any browser, while debugging is supported only in Chrome. To run a Dart web application, open the main HTML file of your application in a browser. Debugging a Dart web application is initiated through a run configuration of the type Dart Web.

    PyCharm integrates with the webdev server tool to compile Dart code into JavaScript if necessary. For versions earlier than Dart SDK 2, the pub serve tool is used.

    When you open a Dart web application in a browser, it normally starts with a built-in server URL like http://localhost:63342/project-name/web/index.html. However, the built-in server is not used to serve the application. Instead, PyCharm automatically starts webdev server on the port specified in the Dart dialog and the browser page is redirected to the webdev server URL (like http://localhost:53322/index.html).

    The work of webdev server is logged in the dedicated Dart Webdev tool window. The tool window opens when you start running or debugging a Dart web application for the first time during the current PyCharm session. You can stop the tool by clicking the Stop Dart Webdev Server button on the toolbar. When you start running or debugging again, webdev server restarts automatically.

    The recommended way to debug Dart web applications is to use a Dart Web configuration. In this mode, webdev server starts with Dart DevTools enabled.

    However, you can still use a JavaScript Debug configuration. For more information, refer to Alternative way to run and debug Dart web applications.

    Create a run/debug configuration

    1. Create a Dart Web run/debug configuration:

      Go to Run | Edit Configurations, in the Edit Configurations dialog that opens, click the Add button (the Add button) on the toolbar and select Dart Web from the list.

      In the Run/Debug Configuration: Dart Web dialog that opens, specify the path to the HTML file that references the Dart code to run or debug and the port on which the webdev server will start the Dart web app .

    Run your application

    • From the Run/Debug Configurations list on the toolbar, select the newly created Dart Web configuration and click the Run button next to it.

      The browser opens at 127.0.0.1:<webdev_port>/<specified_HTML_file>.

    Debug your application

    1. Set the breakpoints in the Dart code, as required.

    2. From the Select run/debug configuration list on the toolbar, select the newly created Dart Web configuration and click the Debug button next to it.

    Alternative way to run and debug Dart web applications

    Besides using a Dart Web run/debug configuration, which is the recommended workflow, with PyCharm, you can still run and debug Dart web applications with a JavaScript Debug configuration.

    Run a Dart web application

    1. Open the HTML file with a Dart reference or select it in the Project tool window.

    2. From the context menu of the editor or selection, select Open in Browser and choose the required browser in the list.

    Create a JavaScript Debug run/debug configuration

    1. Open the HTML file that references Dart or select the file in the Project tool window.

    2. From the context menu, select Create '<HTML_file_name>'. The Run/Debug Configuration: JavaScript Debug dialog opens.

    3. Specify the browser from the Chrome family to debug the application in.

    4. The URL field already shows the URL address of the application in the format http://localhost:<built-in server port>/<project-name>/<relative path to the HTML file>. During a debugging session, the browser will be redirected from this URL to the webdev server URL.

    Start debugging

    1. Configure and set breakpoints in the Dart code.

    2. Initiate a debugging session: choose the created run configuration from the Edit configurations list on the toolbar and click the Debug button. PyCharm opens the specified URL in the chosen browser.

    3. In the Debug tool window that opens, step through the program, stop and resume program execution, examine it when suspended, and so on.

    Testing Dart applications

    PyCharm supports running and debugging Dart tests that are written using the dart test package. You can run tests on any target platform, debugging is supported only for VM tests.

    You can run and debug single tests, test groups, as well as tests from entire files and folders. PyCharm creates a run/debug configuration with the default settings and launches the tests. You can later save this configuration for reuse.

    Run or debug a single test

    Open the test file in the editor, right-click the call of the test() method, and choose Run '<test_name>' or Debug '<test_name>' from the context menu.

      Run or debug a group

      Open the test file in the editor, right-click the call of the group() method, and choose Run '<group_name>' or Debug '<group_name>' from the context menu.

        Run or debug Dart tests from a file

        In the Project tool window, select the file with the tests to run and choose Run '<file_name>' or Debug '<file_name>' from the context menu.

          Run or debug Dart tests from a folder

          In the Project tool window, select the folder with the tests to run and choose Run '<folder_name>' or Debug '<folder_name>' from the context menu.

            Save an automatically generated default configuration

            After a test session is over, choose Save <default_test_configuration_name> from the context menu of the test, test group, test file, or folder.

              Run or debug tests using a previously saved run/debug configuration

              • Choose the required Dart Test configuration from the list on the toolbar and click the Run button or the Debug button.

              Configuring syntax highlighting

              You can configure Dart-aware syntax highlighting according to your preferences and habits.

              1. In the Settings dialog (Ctrl+Alt+S) , go to Editor | Color Scheme | Dart.

              2. Select the color scheme, accept the highlighting settings inherited from the defaults or customize them as described in Colors and fonts.

              Last modified: 11 February 2024
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