Flask-SQLAlchemy uses a ForeignKey column to constrain and join data models, a relationship() method that allows one model to access its related model, and a back_populates property to establish a bi-directional relationship between models such that ...
Classes and Instances Class: A bundle of data and functionality. This can be copied and modified to accomplish a wide variety of programming tasks. A blueprint on how to build an object Class names begin with capital letters classes with multiple...
Python is an interpreted, object-orientated programming language. Python builds server-side applications To run a python file, in the command line, type: python filename.py To use the python shell, type python into the terminal and enter. You c...
Side Effects: an operation, function or expression is said to have a side effect if it modifies some state variable value(s) outside its local environment, while having an observable effect besides returning a value. (Wikipedia on Side Effects) Side ...
Controlling Form Values from State A controlled form is a form that derives its input values from state Consider the following form code import React, { useState } from "react"; function Form() { const [firstName, setFirstName] = useState("Joh...
What is State in React? State: Data that is DYNAMIC in your component. It changes over time as users interact with the application. To use, we must import a function from React called "useState". It is a React Hook. The setup looks as follows: im...
How to set up REACT for Rendering? import React from 'react' import ReactDom from 'react-dom' ReactDom.render( <h1>Hello</h1>, //what we want to display(our entire app) document.getElementbyId("root") //where we want to display it ) On the top, yo...
There are many events that we can use to mutate the DOM based on the event. Some examples are: Mouse: click double click Keyboard keypress keydown keyup For a full list, look at https://developer.mozilla.org/en-US/docs/Web/API/Element ...
There are multiple ways to use javascript to access specific nodes in the DOM. document.getElementById() This method is very specific as IDs are supposed to be unique. It will return only 1 node. the argument should be placed around ' ' or " " ...