Update README.md

README.md

@@ -1,24 +1,25 @@
 # pwa-test
 
-## Project setup
-```
-npm install
-```
+[Original Stack Overflow question](https://stackoverflow.com/questions/68716680/accessing-css-variable-on-mount-in-vue)
 
-### Compiles and hot-reloads for development
-```
-npm run serve
-```
+I'm working on a Vue.js PWA that requires the js to know the value of `env(safe-area-inset-top)`. I have the `env` reassigned to a css variable named `--sat` which I'm reading. But I can't find a way to get its value at the beginning of the lifecycle.
 
-### Compiles and minifies for production
-```
-npm run build
-```
+The [MDN documentation](https://developer.mozilla.org/en-US/docs/Web/API/Window/load_event) says that 
+>The Window `load` event is fired when the whole page has loaded, including all dependent resources such as **stylesheets** and images.
 
-### Lints and fixes files
-```
-npm run lint
+So i've tried the following:
+```javascript
+methods: {
+  setSat() {
+    this.sat = getComputedStyle(document.body).getPropertyValue('--sat');
+  },
+},
+mounted() {
+  window.onload = this.setSat;
+},
 ```
+However this doesn't seem to work. When I open the project on my phone from the home screen as a PWA the `setSat` method does get called by itself but returns `0px`. If I trigger it by clicking a button after the page is loaded it returns the appropriate `48px`.
 
-### Customize configuration
-See [Configuration Reference](https://cli.vuejs.org/config/).
+If I try to run the function on a 0 or even 100ms timeout, the value of `env(safe-area-inset-top)` is still `0px`.
+
+For now I've resorted to waiting a second before getting the value but this is obviously not desirable.