How to get dynamics with jquery

Web page data?

As front-end developers, we all know that jquery is a very popular and powerful Javascript library. It can help us easily manipulate DOM elements, handle events, send AJAX requests, and more. But what should we do when we need to obtain data from dynamic web pages? In this article, I will introduce some common techniques for obtaining dynamic web page data using jquery.

1. Use jquery's ajax method to send a request

jquery's ajax method can help us send HTTP requests to the server and obtain response data. We can use this method to get data for both static and dynamic web pages. The following are the basic steps to use jquery's ajax method to obtain dynamic web page data:

1. Understand the target URL

First, we need to understand the target URL, that is, where we want to obtain the data Website address. Please note that if the website uses Ajax technology for dynamic loading, we need to find the Ajax interface used by the website. You can use your browser's developer tools to look for Ajax requests and find the source of the data. If you don't know the target URL, you can't get the data correctly.

2. Use jquery's $.ajax method to send a request

Next, we can use jquery's $.ajax method to send a request to obtain data. The following are the important options we need to specify when using the $.ajax method:

• url: The address of the target website, including the address of the Ajax interface.
• type: Request type, usually "GET" or "POST".
• dataType: The type of requested data, such as json, xml, html, etc.
• data: Data that needs to be sent when sending a request.

The following is a sample code that uses jquery's $.ajax method to obtain dynamic web page data:

$.ajax({
    url: "https://example.com/ajax",
    type: "GET",
    dataType: "html",
    success: function(response) {
        // 处理获取到的 response 数据
    },
    error: function(xhr, status, error) {
        // 处理请求发生错误的情况
    }
});

In the above code, we use the $.ajax method to send a GET requests to the target URL and requests data in HTML format. After successfully obtaining the data, we can process the obtained data in the success callback function. When an error occurs, we can perform error handling logic in the error callback function.

3. Parse the obtained HTML data

After obtaining the HTML data, we need to parse the HTML data and extract the data we need. We can use jquery's selector to select HTML elements and use jquery's method to extract data. The following is a simple example:

$.ajax({
    url: "https://example.com/ajax",
    type: "GET",
    dataType: "html",
    success: function(response) {
        var data = $(response).find(".target-element").text();
        // 在 .target-element 元素中找到所需的数据
    },
    error: function(xhr, status, error) {
        // 处理请求发生错误的情况
    }
});

In the above code, we use jquery's $.ajax method to send a GET request to the target URL and obtain the data using HTML format. We used the $(response).find(".target-element") selector to select the target element in the HTML and used the .text() method to extract the text. Finally, we can use the variable data to save the data or process it further.

2. Dynamically load data in the web page and extract it

In addition to using the ajax method to send requests to obtain data, we can also dynamically load data in the web page and extract information. This is often at the heart of AJAX technology and is the approach used by many modern web applications. The following are common ways to use jquery:

1. Load data using jquery's load method

jquery's load method can help us load data from other web pages or HTML files . We can use this method to load data into the page and then use jquery's selectors and methods to extract the data. The following is a sample code that uses jquery's load method to dynamically load data:

$("#target-element").load("https://example.com/ajax .target-element", function() {
    var data = $("#target-element").text();
    // 在 #target-element 元素中找到所需的数据
});

In the above code, we use jquery's load method to load data from the Ajax interface of the target website and insert it into # target-element element. In the callback function of the load method, we can use jquery's selectors and methods to extract the data we need.

2. Use jquery's get and post methods to send requests

jquery also provides get and post methods to send GET or POST requests to the server. These two methods are very similar to the ajax method, but they are more convenient and can insert the response data directly into the page. The following is a sample code that uses jquery's get method to obtain data and insert it into the page:

$.get("https://example.com/ajax", function(response) {
    $("#target-element").html(response);
    var data = $("#target-element .target-element").text();
    // 在 #target-element 元素中找到所需的数据
});

In the above code, we use jquery's get method to obtain data from the Ajax interface of the target website, And insert it into the element of #target-element. In the callback function of the get method, we can use jquery's selectors and methods to extract the data we need.

3. Conclusion

The above are some methods and techniques for using jquery to obtain dynamic web page data. As web applications evolve, it becomes easier to obtain data, so we can use these methods to create more powerful web applications.

No matter which method we use, we need to understand the structure of the target website and the technology used. We need to know which selectors and methods work for different types of data and decide what to do with that data. By using some simple tricks and tools, we can easily get the data we need and use them in our web applications.

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