René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Cannot read property 'mainScreen' of undefined - when trying to get dark mode status","articleBody":"**Environment**\r\nProvide version numbers for the following components (information can be retrieved by running `tns info` in your project folder or by inspecting the `package.json` of the project):\r\n - CLI: 7.0.8\r\n - Cross-platform modules: \"@nativescript/firebase\": \"rc\"\r\n - Android Runtime: -\r\n - iOS Runtime: \r\n```\r\nInstalling on device E2CFC71D-3295-443F-B505-B3B83D45553F...\r\nSuccessfully installed on device with identifier 'E2CFC71D-3295-443F-B505-B3B83D45553F'.\r\nRestarting application on device E2CFC71D-3295-443F-B505-B3B83D45553F...\r\nSuccessfully synced application org.nativescript.aaa on device E2CFC71D-3295-443F-B505-B3B83D45553F.\r\n(RunningBoardServices) [com.apple.runningboard:connection] Identity resolved as application\u003corg.nativescript.aaa\u003e\r\n***** Fatal JavaScript exception - application has been terminated. *****\r\nNativeScript encountered a fatal error: Uncaught TypeError: Cannot read property 'mainScreen' of undefined\r\nat\r\n../node_modules/@nativescript/theme/index.js(file: node_modules/@nativescript/theme/index.js:25:33)\r\nat __webpack_require__(file: app/webpack/bootstrap:74:0)\r\nat ../node_modules/babel-loader/lib/index.js!../node_modules/vue-loader/lib/index.js?!./components/Home.vue?vue\u0026type=script\u0026lang=js\u0026(file:///app/bundle.js:42:77)\r\nat __webpack_require__(file: app/webpack/bootstrap:74:0)\r\nat ./components/Home.vue?vue\u0026type=script\u0026lang=js\u0026(file: app/components/Home.vue?5625:1:0)\r\nat __webpack_require__(file: app/webpack/bootstrap:74:0)\r\nat ./components/Home.vue(file: app/components/Home.vue:1:0)\r\nat __webpack_require__(file: app/webpack/bootstrap:74:0)\r\nat (file: app/app.js:1:0)\r\nat ./app.js(file:///app/bundle.js:403:30)\r\nat __webpack_require__(file: app/webpack/bootstrap:74:0)\r\nat checkDeferredModules(file: app/webpack/bootstrap:43:0)\r\nat webpackJsonpCallback(file: app/webpack/bootstrap:30:0)\r\nat (file:///app/bundle.js:2:57)\r\nat require(:1:137)\r\n(CoreFoundation) *** Terminating app due to uncaught exception 'NativeScript encountered a fatal error: Uncaught TypeError: Cannot read property 'mainScreen' of undefined\r\nat\r\n../node_modules/@nativescript/theme/index.js(file: node_modules/@nativescript/theme/index.js:25:33)\r\nat __webpack_require__(file: app/webpack/bootstrap:74:0)\r\nat ../node_modules/babel-loader/lib/index.js!../node_modules/vue-loader/lib/index.js?!./components/Home.vue?vue\u0026type=script\u0026lang=js\u0026(file:///app/bundle.js:42:77)\r\nat __webpack_require__(file: app/webpack/bootstrap:74:0)\r\nat ./components/Home.vue?vue\u0026type=script\u0026lang=js\u0026(file: app/components/Home.vue?5625:1:0)\r\nat __webpack_require__(file: app/webpack/bootstrap:74:0)\r\nat ./components/Home.vue(file: app/components/Home.vue:1:0)\r\nat __webpack_require__(file: app/webpack/bootstrap:74:0)\r\nat (file: app/app.js:1:0)\r\nat ./app.js(file:///app/bundle.js:403:30)\r\nat __webpack_require__(file: app/webpack/bootstrap:74:0)\r\nat checkDeferredModules(file: app/webpack/bootstrap:43:0)\r\nat webpackJsonpCallback(file: app/webpack/bootstrap:30:0)\r\nat (file:///app/bu\u003c…\u003e\r\n\r\n```\r\n - Plugin(s):\r\n    \"@nativescript/core\": \"~7.0.0\",\r\n    \"@nativescript/firebase\": \"rc\",\r\n    \"@nativescript/theme\": \"nativescript-vue\" (tried with rc also),\r\n    \"nativescript-vue\": \"~2.8.0\"\r\n\r\n**Describe the bug**\r\nPretty much stock nativescript-vue installation with NativeScript CLI 7.0.8.\r\nIn my main screen I import the theme using `import Theme from \"@nativescript/theme\";`\r\nThen I'm trying to get the dark mode status like this:\r\n```\r\nmounted () {\r\n      console.log(Theme.getMode())\r\n},\r\n```\r\nI get an error:\r\n`(CoreFoundation) *** Terminating app due to uncaught exception 'NativeScript encountered a fatal error: Uncaught TypeError: Cannot read property 'mainScreen' of undefined`\r\n\r\n**To Reproduce**\r\nJust try to use `Theme.getMode()` on NativeScript 7 with Vue (might be the same with others as well)\r\n\r\n**Expected behavior**\r\nHaven't used this feature before, I guess it will give you a string of \"ns-light\" or \"ns-dark\" and won't break your app.\r\n\r\n**Sample project**\r\nCan't reproduce this on play.nativescript.org as it uses the old NativeScript. As far as I've tested it seems to be the issue only with NativeScript 7\r\n","author":{"url":"https://github.com/butaminas","@type":"Person","name":"butaminas"},"datePublished":"2020-09-13T12:26:00.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":10},"url":"https://github.com/275/theme/issues/275"}