javascript and thymeleaf

-

 th:each in Thymeleaf is primarily used for iterating over collections within HTML templates, not directly within JavaScript code. It processes on the server-side to generate HTML before the JavaScript executes in the browser. However, you can use th:each to generate JavaScript code dynamically based on data from your server. Here's how:

Generating JavaScript with th:each
  • Server-Side Iteration: Use th:each within a <script> tag to loop through a collection provided by your Spring Boot controller.
Code
    <script th:inline="javascript">        /*<![CDATA[*/        var items = [];        /*[# th:each="item : ${itemList}"]*/            items.push(/*[[${item}]]*/);        /*[/]*/        console.log(items);        /*]]>*/    </script>
  • th:inline="javascript": Enables Thymeleaf to process the script tag.
  • /*<![CDATA[*/ and /*]]>*/: Wraps the JavaScript code to prevent XML parsing errors, especially with older Thymeleaf versions.
  • /*[# th:each="item : ${itemList}"]*/: Starts a Thymeleaf loop over the itemList.
  • items.push(/*[[${item}]]*/);: Adds each item to the JavaScript items array. /*[[${item}]]*/ is an inline expression that will be replaced with the actual item value.
  • /*[/]*/: Closes the th:each loop.
  • Accessing Generated Data: Your JavaScript code can now use the items array populated by the server-side Thymeleaf processing.
Important Considerations
  • Server-Side vs. Client-Side:
    Thymeleaf processes th:each on the server, generating HTML and JavaScript. JavaScript then executes on the client's browser.
  • Data Types:
    Ensure that the data types being passed from the server are compatible with JavaScript.
  • Inline Expressions:
    Use /*[[${variable}]]*/ for inline expressions within JavaScript, as opposed to ${variable} which is used in HTML attributes.
  • CDATA:
    The CDATA section is crucial for older Thymeleaf versions to prevent parsing errors.
  • View Source:
    Inspect the generated HTML source in your browser to verify the JavaScript output.
Example
Controller (Java):
Java
import org.springframework.stereotype.Controller;import org.springframework.ui.Model;import org.springframework.web.bind.annotation.GetMapping;import java.util.Arrays;import java.util.List;@Controllerpublic class MyController {    @GetMapping("/example")    public String example(Model model) {        List<String> items = Arrays.asList("apple", "banana", "cherry");        model.addAttribute("itemList", items);        return "example";    }}
Template (HTML):
Code
<!DOCTYPE html><html xmlns:th="http://www.thymeleaf.org"><head>    <title>Thymeleaf Example</title></head><body>    <h1>Thymeleaf Example</h1>    <script th:inline="javascript">        /*<![CDATA[*/            var items = [];            /*[# th:each="item : ${itemList}"]*/                items.push(/*[[${item}]]*/);            /*[/]*/            console.log(items);        /*]]>*/    </script></body></html>
This example will output the following JavaScript in your browser's console:
JavaScript
var items = ["apple", "banana", "cherry"];console.log(items);
In summary, while th:each cannot be used directly inside JavaScript code, it can generate JavaScript code based on the data from the server, allowing you to dynamically create JavaScript arrays or other structures.

Comments

Post a Comment

Popular posts from this blog

image work in springboot

-
 Bean file :         @Lob @Column(length = Integer.MAX_VALUE) private byte[] images;          public byte[] getImages() {           return images;            }          public void setImages(byte[] images) {           this.images = images;            } save image controller :       @PostMapping("/") public String saveHolidayPackage(@ModelAttribute CreateHolidayPackageOne createHolidayPackageOne,               @RequestParam("image") MultipartFile file,HttpSession httpSession) throws IOException { createHolidayPackageOne.setImages(file.getBytes()); createHolidayPackageOneRepo.save(createHolidayPackageOne); return "Admin/CreateHolidayPackageDetails"; } retrieve image from database controller :         ...
Read more

Springboot important annotation

-
Image
  Spring Boot Annotations Spring Boot’s annotations are key to getting up to speed with the framework. They allow you to direct the framework to do your bidding, taking control and overriding its defaults when needed. Annotations are quick, easy to use, and orders of magnitude faster than building the equivalent functionality yourself. You can learn more in Spring’s documentation. The  PDF  or  web  versions are essential reading if you plan on working with Spring Boot. Knowing how to use annotations can level up your game and help you get the most out of the framework. Listed below are several common annotations, some of them with sample code. Spring Boot works with  Java ,  Kotlin , and Groovy. I’ll use Java for the examples in this article. Basic Setup @SpringBootApplication @Configuration @ComponentScan @EnableAutoConfiguration Request Responses @GetMapping @RequestMapping @RequestParam Component Types @Component @Service @Repository @Controller @R...
Read more