Build and Test

Version added 26-Jun-2018| Modified 10-Jun-2019

After developing the QML app, you must build the app and verify its functionality.

Add Recipe File

webOS OSE uses OpenEmbedded of Yocto project to build its components. You must write a recipe that configures the build environment. For more details about the recipe, see Yocto project reference manual.

  • Create and update the file : <qml-app-name>.bb

    • Directory : build-webos/meta-webosose/meta-webos/recipes-webos/<qml-app-name>

where <qml-app-name> is the name of the qml app. For the sample qml app, <qml-app-name> must be replaced by "".

SECTION = "webos/apps"
LICENSE = "Apache-2.0"
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/Apache-2.0;md5=89aea4e17d99a7cacdbeed46a0096b10"
DEPENDS = "qtbase qt-features-webos qtdeclarative pmloglib"
RDEPENDS_${PN} += "qml-webos-framework qml-webos-bridge"

PR = "r0"
inherit webos_qmake5
inherit webos_submissions
inherit webos_app
FILES_${PN} += "${webos_applicationsdir}"

A brief explanation of the above file:

  • Line(1~4) : Basic descriptions of the component.

  • Line(6) : A list of a package's build dependencies. Add "qtbase", "qt-features-webos", "qtdeclarative", and "pmloglib".

  • Line(7) : A list of a package's runtime dependencies (other packages) that must be installed in order for the built package to run correctly. Add "qml-webos-bridge" and "qml-webos-framework".

  • Line(9) : Version of the component. For the webOS OSE component, this field is mandatory.

  • Line(10) : Revision version of the recipe. Each recipe requires a counter to track its modification history. Make sure that you increment the version when you edit the recipe, unless you only change the value of the WEBOS_VERSION field or comments.

  • Line(12) : Instruct OpenEmbedded that the component uses QMake for configuration, which is the preferred choice for webOS components.

  • Line(13) : Instruct OpenEmbedded to use the WEBOS_VERSION value as the component version number. If you develop your component on a local repository, this entry is required.

  • Line(14) : Inherit webos_app, because the component is an app.

  • Line(16) : ${webos_applicationsdir} indicates /usr/palm/applications${PN} is the package name, which is set to

Configure Local Source Directory

To build a component that is located on the local system, you must specify the directory information.

  • Create and update the file : webos-local.conf

    • Directory : build-webos

For the sample QML app (, you must provide the local path where the source exists.

INHERIT += "externalsrc" = "/home/username/project/" = "/home/username/project/" =".local0"

A brief explanation of the above file:

  • Line(1) : Inherit "externalsrc" bbclass file.

  • Line(2) : The local source directory. The syntax of the property is EXTERNALSRC_pn-<component>.

  • Line(3) : The local build directory. The syntax of the property is EXTERNALSRC_BUILD_pn-<component>.

  • Line(4) : The appended revision version (PR) for building local source files. The syntax of the property is PR_append_pn-<component>. This property is optional.

We recommend that you add a trailing slash (/) at the end of all local directory paths, as in Line(2) and Line(3).

Build, Run, and Verify

  1. Build the QML app.

    To build the component on the OpenEmbedded environment, enter the following commands on the shell:

    build-webos$ source oe-init-build-env
    build-webos$ bitbake

    For more information, see Building webOS OSE.


  2. Copy the IPK to the target.

    When the build is successful, oe-related directories are created under the project root directory. These directories are linked to the directory where the build output is generated from the actual build-webos sub-directory.
    ├── appinfo.json
    ├── build
    ├── icon.png
    ├── main.qml
    ├── oe-logs -> /home/username/build/build-webos/BUILD/work/raspberrypi3-webos-linux-gnueabi/
    └── oe-workdir -> /home/username/build/build-webos/BUILD/work/raspberrypi3-webos-linux-gnueabi/

    If you go to oe-workdir/deploy-ipks/raspberrypi3, you can see file.$

    Copy the IPK file to the target device using the scp command.

    ~/project/$ scp root@


  3. Install the app on the target.

    Connect to the target using the ssh command and install

    $ ssh root@
    root@raspberrypi3:~# cd /media/internal/downloads/
    root@raspberrypi3:/media/internal/downloads# opkg install
    Installing (1.0.0) on root.


  4. Discover the LS2 configuration files.

    To make LS2 daemon scan the LS2 configuration files of the app, use the ls-control command as follows.

    root@raspberrypi3:/media/internal/downloads# ls-control scan-services
      telling hub to reload setting and rescan all directories
    For the QML app, LS2 configuration files are generated during the build in step 1. To run the app properly, you must make the system scan the newly generated configuration files.


  5. Scan the app.

    To make System and Application Manager (SAM) scan the app, restart SAM using the systemctl command. This step is required so that the app can be added to the app list, which in turn makes the app appear on the Home Launcher.

    root@raspberrypi3:/# systemctl restart sam
    Rebooting the target after step 3 will have the same effect as running step 4 and step 5. However, using the commands in step 4 and step 5 allows you to continue testing without rebooting.


  6. Run the QML app.

    Use the Windows key on your keyboard to display the Home Launcher. Click the app icon to see the window titled "QML app" with the following page:



  7. Verify the execution of the QML app.

    • Using SAM

      You can check whether the app is running by using SAM. For more SAM methods, see com.webos.service.applicationmanager.

      root@raspberrypi3:/# luna-send -i -f luna://com.webos.service.applicationmanager/running '{"subscribe":true}'
          "subscribed": true,
          "running": [
                  "id": "",
                  "webprocessid": "",
                  "defaultWindowType": "card",
                  "appType": "native_qml",
                  "processId": "2779"
          "returnValue": true
    • Using the app

      • Click on the screen, and the UTC time is printed on the screen.

    • Using logs

      • When the app is first launched on launcher

        The app is launched and registered to SAM by qml-runner. The app gets the "params" value from qml-runner. As the app is in the foreground, windowState value is "4". qml-runner [] QMLApp LAUNCH_PARAMS {     "params": {     } } qml-runner [] QMLApp WINDOW_CHANGED {     "status": 4 }
      • When the app goes to the background by launching another app, windowState is changed to "1". qml-runner [] QMLApp WINDOW_CHANGED {     "status": 1 }
      • When relaunching the app while the app is in the foreground and running

        Specify the "params" parameter to pass specific values to the app via SAM, as follows:

        root@raspberrypi3:/# luna-send -n 1 luna://com.webos.applicationManager/launch '{"id":"", "params" : {"test":"key1"}}'

        See the log. qml-runner [] QMLApp LAUNCH_PARAMS {     "params": {         "test": "key1"     } } qml-runner [] QMLApp WINDOW_CHANGED {     "status": 4 }
Except as noted, this content is licensed under Creative Commons Attribution 4.0 and sample code is licensed under Apache License 2.0.