angular basics

Cross Domain Ajax

What is same origin policy?
Browsers allow a web page to make AJAX requests only with in the 
same domain. Browser security prevents a web page from making
AJAX requests to another domain. This is called same origin policy.

URIs have the same origin
 http://localhost:1234/api/employees
http://localhost:1234/Employees.html

Different origins: Because they have different port numbers
http://localhost:1234/api/employees
http://localhost:5678/Employees.html
Different origins: Because they have different domains
http://mahesh.com/api/employees
http://mahesh.net/Employees.html



Comments

Post a Comment

Popular posts from this blog

reactjs questions part 4

A prop change does not re-render a component if the prop is stored as a local variable. It only re-renders when the prop is stored as a state variable. =======  I take 2-3 interviews per week on average for react devs. The most common one I ask my candidates is this: Explain how react works under the hood to me like I'm 5 yr old What problem did react come to solve? What are composable components? How do you separate logic and style? What are the security measures to be taken to avoid data leak in frontend TYPESCRIPT specific How do you validate form input data  How do you design typesafe components GENERAL what are accessible components, how do you design them ? State management - redux vs context API.  --------------------------2------------------------------- Here are some key API-related questions to prepare for your React.js interview: API Calls and Data Manipulation How do you make API calls in a React application and handle the response data? What is the best pract...
Read more

ReactJS: How and when to force a React component to re-render

Image
What is force re-rendering? Force re-rendering in React is like pressing the refresh button on a webpage, even when the page seems just fine. In React, it means telling a component to update and redraw itself, even if nothing has really changed in the data (stat/props) it uses. Although React is usually good at knowing when it is time to update a component, there are moments when you want to take the reins and tell it to refresh a certain part of the codebase. In this article, we will explore this in more detail. Understanding React’s rendering behavior Let’s take a closer look at how React’s rendering process works by default. To understand when and why you might need to nudge React into re-rendering, you need to get familiar with its underlying architecture. At the heart of  React’s rendering  magic lies the Virtual DOM. Imagine it as a clone of the actual DOM, the structure of your webpage. React uses this Virtual DOM to figure out what needs to be updated when your data ch...
Read more

Q: Error Boundary in React that catches an error and displays a fallback UI

ErrorBoundary Component : This catches errors in its child components and displays a fallback UI ( Something went wrong. ). MyComponent : This component intentionally throws an error to demonstrate how the error boundary works. App Component : Wraps  MyComponent  with  ErrorBoundary  to catch and handle errors  When you run this code, you'll see "Something went wrong." displayed on the screen because MyComponent throws an error, which is caught by the ErrorBoundary .  CREATING SAMPLE: Let's create a simple example of an error boundary in React that catches an error and displays a fallback UI when an error occurs in a component. 1.ErrorBoundary Component import React , { Component } from " react " ; class ErrorBoundary extends Component {   constructor ( props ) {     super ( props ) ;     this . state = { hasError : false } ;   }   static getDerivedStateFromError ( error ) {     ...
Read more