3. React

  • 3.17. React shouldComponentUpdate() method

    The shouldComponentUpdate() format of the method is as follows: shouldComponentUpdate(nextProps, nextState) sho...
    2025-10-25 13:34:29 UTC
  • 3.18. React getSnapshotBeforeUpdate () method

    The render() format of the method is as follows: getSnapshotBeforeUpdate(prevProps, prevState) getSnapshotBefor...
    2025-10-25 13:34:29 UTC
  • 3.19. React componentDidUpdate() method

    The componentDidUpdate() format of the method is as follows: componentDidUpdate(prevProps, prevState, snapshot) ...
    2025-10-25 13:34:30 UTC
  • 3.20. React componentWillUnmount() method

    componentWillUnmount() format of the method is as follows: componentWillUnmount() componentWillUnmount() meth...
    2025-10-25 13:34:30 UTC
  • 3.21. React AJAX

    Data from the React component can be accessed through the componentDidMount method, and when getting data from the serve...
    2025-10-25 13:34:29 UTC
  • 3.22. React forms and events

    In this section we will discuss how to use forms in React. HTML form elements are different from other DOM elements in Rea...
    2025-10-25 13:34:29 UTC
  • 3.23. React Refs

    React supports a very special attribute Ref which you can use to bind to the render() on any component of the output...
    2025-10-25 13:34:30 UTC

Principles, Technologies, and Methods of Geographic Information Systems

 102

In recent years, Geographic Information Systems (GIS) have undergone rapid development in both theoretical and practical dimensions. GIS has been widely applied for modeling and decision-making support across various fields such as urban management, regional planning, and environmental remediation, establishing geographic information as a vital component of the information era. The introduction of the “Digital Earth” concept has further accelerated the advancement of GIS, which serves as its technical foundation. Concurrently, scholars have been dedicated to theoretical research in areas like spatial cognition, spatial data uncertainty, and the formalization of spatial relationships. This reflects the dual nature of GIS as both an applied technology and an academic discipline, with the two aspects forming a mutually reinforcing cycle of progress.