Learn the Tutorial on Learning to use the Clj Tagsoup Framework to Process HTML
Learn the tutorial of using the CLJ Tagsoup framework to process HTML
Overview:
ClJ Tagsoup is a CLOJURE library for handling HTML. It provides a simple and flexible way to analyze and operate HTML documents.This tutorial will take you to gradually learn how to use the CLJ Tagsoup framework to process HTML.
Step 1: Install ClJ tagsoup
First, we need to install the CLJ TAGSOUP library.You can add the following dependencies to the project file (Project.clj) of the Clojure project:
clojure
:dependencies [[clj-tagsoup "0.4.4"]]
Then, the following command will be added to the project:
bash
lein deps
Step 2: Import the clj tagsoup library
In the CLOJURE file, you need to import the CLJ Tagsoup library so that you can use the functions.Use the following code line to guide the library:
clojure
(ns my-app.core
(:require [clj-tagsoup.core :as tagsoup]))
Step 3: Analyze the html document
Using CLJ Tagsoup, you can use the `tagsoup/PARSE` function to parse the HTML document.The following is a simple example:
clojure
(let [html "<html><body><h1>Hello, Clj TagSoup!</h1></body></html>"]
(println (tagsoup/parse html)))
Run the above code to analyze the output HTML document.
Step 4: Extract HTML element
Using CLJ Tagsoup, you can use CSS to select the syntax to extract specific HTML elements.The following is an example:
clojure
(let [html "<html><body><h1>Hello, Clj TagSoup!</h1></body></html>"
parsed-html (tagsoup/parse html)]
(println (tagsoup/select parsed-html [:body :h1])))
Run the above code will output `[<h1> Hello, CLJ Tagsoup! </H1>]`, which contains the selected HTML element.
Step 5: Operation HTML elements
Clj tagsoup also provides some functions so that you can operate HTML elements.Here are some commonly used examples:
-Capor the text content of the element:
clojure
(let [html "<html><body><h1>Hello, Clj TagSoup!</h1></body></html>"
parsed-html (tagsoup/parse html)
element (first (tagsoup/select parsed-html [:body :h1]))]
(println (tagsoup/text element)))
Run the above code, the output `Hello, CLJ TAGSOUP!
-Early obtain the attributes of the element:
clojure
(let [html "<a href='https://example.com'>Link</a>"
parsed-html (tagsoup/parse html)
element (first (tagsoup/select parsed-html [:a]))]
(println (tagsoup/attrs element)))
Run the above code, the output `{: href" https://example.com "}`, which contains the attributes of the selected element.
Step 6: Save the modified HTML document
If you modify HTML and want to save the modified document, you can use the `tagsoup/render` function.The following is an example:
clojure
(let [html "<html><body><h1>Hello, Clj TagSoup!</h1></body></html>"
parsed-html (tagsoup/parse html)
modified-html (tagsoup/set-attr! (tagsoup/select parsed-html [:body :h1]) :style "color: red")]
(spit "modified.html" (tagsoup/render modified-html)))
The above code will use the `tagsoup/set -rstr!` Function to set the `style` property of the selected element to` color: red`, and save the modified HTML document to the `modify.html` file.
The above is the basic tutorial of processing HTML with the CLJ Tagsoup framework.By mastering these techniques, you will be able to easily analyze and operate HTML documents.
Java code example:
If you want to use the CLJ Tagsoup framework in Java to process HTML, you can implement it by using the Java calling function of Clojure.The following is an example of the Java code of the above example:
import clojure.java.api.Clojure;
import clojure.lang.IFn;
public class HTMLProcessor {
public static void main(String[] args) {
IFn require = Clojure.var("clojure.core", "require");
require.invoke(Clojure.read("clj-tagsoup.core"));
IFn parse = Clojure.var("clj-tagsoup.core", "parse");
String html = "<html><body><h1>Hello, Clj TagSoup!</h1></body></html>";
Object parsedHtml = parse.invoke(html);
IFn select = Clojure.var("clj-tagsoup.core", "select");
Object selectedElements = select.invoke(parsedHtml, Clojure.read("[:body :h1]"));
System.out.println(selectedElements);
}
}
Run the above Java code the same result as the output as the Clojure example.
I hope that this CLJ Tagsoup framework processing HTML tutorial can help you get started quickly and learn to use the framework to process HTML documents.If you need more help, please refer to the official documentation and example code of ClJ Tagsoup.
