How to execute JavaScript from Native C code in Tizen?

Original Created Mar 24, 2017 | Regeneration Apr 22, 2026

Question

I'm trying to execute JavaScript code from a native Tizen application (written in C) but my function keeps failing. Here's the problematic code:

static Evas_Object* load_html_file(Evas_Object* parent)
{
    Evas *e_webview = evas_object_evas_get(parent);
    Evas_Object *browser = ewk_view_add(e_webview);
    Ewk_Settings *settings = ewk_view_settings_get(browser);
    ewk_settings_javascript_enabled_set(settings, EINA_TRUE);

    char* javaScript =
        "function setWallpaperSuccess() {}"
        "function setWallpaperError() {}"
        "function test() {"
        "    try {"
        "        tizen.systemsetting.setProperty(\"HOME_SCREEN\", \"file:///opt/usr/media/Downloads/2017-03-20_RiverofLife_1080x1920_no.jpg\", setWallpaperSuccess, setWallpaperError);"
        "    }"
        "    catch (error) {"
        "        console.log(\"Error: \" + error); return 'exceptionhappened';"
        "    } return 'thisworkedorwhat';"
        "}"
        "test();";
    ewk_view_script_execute(browser, javaScript, JScallback, NULL);
    elm_win_resize_object_add(parent, browser);
    evas_object_show(parent);
    evas_object_show(browser);
    return browser;
}

static void JScallback(Evas_Object* o, const char* result_value, void* user_data) {
    dlog_print(DLOG_INFO, LOG_TAG, "[scriptCallback] return value: %s\n", result_value);
}

The sdb dlog always prints:

I/My-Experiment-App (31448): [scriptCallback] return value: exceptionhappened

Here are the privileges declared in my TizenManifest.xml:

<privileges>
    <privilege>http://tizen.org/privilege/mediastorage</privilege>
    <privilege>http://tizen.org/privilege/network.get</privilege>
    <privilege>http://tizen.org/privilege/systemsettings</privilege>
    <privilege>http://tizen.org/privilege/internet</privilege>
    <privilege>http://tizen.org/privilege/appmanager.launch</privilege>
    <privilege>http://tizen.org/privilege/externalstorage</privilege>
</privileges>

Could anyone help me understand why this is failing?

Answer

Problem Understanding

The JavaScript code is executing but failing in the try block, causing it to enter the catch block and return 'exceptionhappened'. This indicates that the tizen.systemsetting.setProperty() function is not working as expected.

Solution Methods

Verify JavaScript Execution: First, confirm that basic JavaScript execution is working by testing with a simple console.log statement.
Check Privileges: Ensure all required privileges are properly declared and granted.
Debug the System Setting API: Test the systemsetting API with simpler parameters to isolate the issue.

Code Examples

Here's a simplified test to verify JavaScript execution:

char* testScript = 
    "function test() {"
    "    console.log('JavaScript is working!');"
    "    return 'success';"
    "}"
    "test();";
ewk_view_script_execute(browser, testScript, JScallback, NULL);

Additional Tips

Make sure the file path you're trying to use exists and is accessible
Verify that the systemsetting API is supported on your Tizen version
Check the official documentation for any known limitations of the systemsetting API