To understand how evolution has occurred it is necessary to talk about specific bones and their transformations through time. This is not directly taught in the class but is done on your own with the help of lab guides. Technically there is not a lab for the course, but part of the course requires you to study and learn the basic vertebrate skeleton, the skulls of three vertebrates, and a set of mammalian teeth. If a question requires a more extended answer I will work with people outside of class. Questions during class are encouraged and expected. Although most of my work is now done in geology I have never lost my fascination with paleotology and am willing to work with anyone who wants to take the course. My graduate degrees are in this subject, and I love teaching it. Permission of the instructor should be gained if you are not sure you are prepared for the class but it has never been a problem in the past. Because the course has in the past had geologists with little background in biology, and biologists with little background in geology, I have learned that I must provide background to both groups for many of the subjects taught. I have placed prerequisites of either an introductory geology or an introductory biology course, but they are technically not necessary. My undergraduate degree is in biology, plus my graduate work (MS and PhD are both in vertebrate paleontology) included course work and advsors in both zoology and geology so I know the backgrounds and perspectives of both groups. The course is meant for for geology and biology majors and I work to speak to both groups equally. Yet this error also disappears in a split second after the screen loads.233 Miller Hall - phone 6531 Vertebrate Paleotology is an elective course exploring the origin and history of the vertebrate taught by Lynn S. 'package:flutter/src/widgets/text.dart': Failed assertion: line 298 pos 10: 'data != null' Additionally, when I just comment out that part of code, another error appears which I believe to be caused by the same reason, populating things without first waiting on the info.Ī non-null String must be provided to a Text widget. I've tried to populated the weather forecast lists in initState() but that crashes my app. The app loads and works perfectly, just a second or so after the screens are created but I can't deploy the app with this red screen popping up. I can't make selectedWeather() async, as the Children part of the Row within listView demands a list not a Future. Of course, I can't make the build() widget asynchronous, but I've made a method updateUI() async, where it populates the lists used in selectedWeather(). I feel like the main problem is it's loading the UI without getting the information first. #4 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4502:15) #3 StatefulElement.build (package:flutter/src/widgets/framework.dart:4619:28) #2 _HomeScreenState.build (package:clear_skies/screens/HomeScreen.dart:521:41) #1 _HomeScreenState.**selectedWeather** (package:clear_skies/screens/HomeScreen.dart:356:22) (dart:core-patch/growable_array.dart:146:60) When the exception was thrown, this was the stack: HomeScreen file:///E:/Projects/flutter/myapps/clear_skies/lib/screens/LoadingScreen.dart:37:18 I suspect that this is causing the issue, as in my stack trace: The relevant error-causing widget was: Used as a child of the final Row in build().Īll this code does is return the corresponding forecast information based on what a user taps. /selectedIndex is 0 by default, when "This Week" is selected, it becomes 1, returning The SelectedWeather method is this: ///Returns the hourly or daily weather forecast based on which tab is selected. MainAxisAlignment: MainAxisAlignment.start,ĬrossAxisAlignment: CrossAxisAlignment.stretch, I've managed to isolate it inside my code, it's the bottom container I have displaying forecast information. RangeError (index): Invalid value: Valid value range is empty: 0 The following RangeError was thrown building HomeScreen(dirty, state: _HomeScreenState#9b318): My app goes from a quick loading screen, to a home screen, but inbetween, the screen flashes red for a second with the following error: I have been attempting to solve this bug for hours and just can't seem to fix it.
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