JavaScript/TypeScript Validate Json file with Json schema
Json file is widely used for many purposes. To consume the data, we somehow need to validate the json file. It is ok to ...
JavaScript/TypeScript 
Dart and Flutter Flutter Dropdown Button hint text and initial value
Dropdown is one of the common ways to let a user select an option from a list. Let's learn how to implement it in Flutte...
Dart and Flutter Flutter Alert/Simple Dialog examples
When we want to tell a message to a user, showing the message on a dialog is one of the ways. Flutter offers the followi...
Dart and Flutter Dart/Flutter Constructors tutorial with examples
Constructor is one of the basics to implement dart class. There are some features that I didn't know before writing this...
JavaScript/TypeScript TypeScript Hack the original behavior
Dependency doesn't support what you want? Then, hacking the code might be the solution. This article tries to replace th...
Dart and Flutter Flutter Riverpod Handling Future and dispose in StateNotifier
It took me a while to find out how to implement a Provider that uses FutureProvider in it and disposes of a variable cre...
Dart and Flutter Flutter Dynamic TextField creation with Riverpod
I have posted the following article before. The code uses neither Riverpod nor Provider. It is implemented by using Stat...
Dart and Flutter Flutter 4 ways to hide persistentFooterButtons
Scaffold Widget has persistentFooterButtons property. How can we implement it if we want to show and hide it depending o...
JavaScript/TypeScript Make an Event Listener test simpler by Promise
A unit test should test only one thing but there might be some cases that a test checks multiple things because those va...
JavaScript/TypeScript OR Operator causes a misunderstanding
OR operator "||" is useful to set a default value if the target variable is not set but it is easy to make a mistake eve...