- Part 1: Adding and Loading the Library
- Part 2: Using Selectors
- Part 3: Reacting to Events
- Part 4: Ajax
Over a decade later, it is core to how many sites function and continues to serve as a fundamental web technology driving nearly all interactive websites and projects.
Using Ajax in jQuery
Note: Retrieving data from a service or content from a webpage can have many potential challenges. To protect the user from different ways they can be attacked or preyed upon, many browsers have built-in safeguards that block out-going requests across protocols (HTTP or HTTPS), depending on Cross-origin resource sharing (CORS) rules, and on the content in which data sent or requested. Depending on the service or server, there be additional rules or expectations as well.
Similar to using a selector and a function on the result, the ajax() function in jQuery accepts an object parameter of different properties to set. The done() and fail() functions are called depending on the outcome. If everything worked, the done() function is called. If not, or there was a problem of some sort, the fail() function is called.
Once content has been retrieved (and no problems were encountered), additional actions can be taken depending on the content and how it should be handled. For example, when working with text content, a common action might be to append the text to an element or act on it somehow.