Thymeleaf: add parameter to current url

问题

I'm at

http://example.com/some/page?p1=11

and I want to add a parameter to current url without having to redefine it:

http://example.com/some/page?p1=11&p2=32

with something like:

<a th:href="@{?(p2=32)}">Click here</a>

but the above code return http://example.com/some/page?&p2=32 (removes the p1 parameter).

How can I do it using Thymeleaf?

回答1:

The easiest solution is concatenating "requestURI" and "queryString". Here is example:

<div th:with="currentUrl=(${#httpServletRequest.requestURI + '?' + #strings.defaultString(#httpServletRequest.queryString, '')})">
   <a th:href="@{${currentUrl}(myparam=test)}">click here</a>
</div>

Result for "http://localhost:8080/some-page?param1=1":

 http://localhost:8080/some-page?param1=1&myparam=test

Result for "http://localhost:8080/some-page":

 http://localhost:8080/some-page?&myparam=test

Drawback:
Thymeleaf doesn't overwrite parameters - only adds parameters to URL. So if you user click once again to that URL, the result will be:

http://localhost:8080/some-page?param1=1&myparam=test&myparam=test

References:
http://forum.thymeleaf.org/How-to-link-to-current-page-and-exchange-parameter-td4024870.html

EDIT:

Here is some workaround, which removes parameter "myparam" from the URL:

<div th:with="currentUrl=(${@currentUrlWithoutParam.apply('myparam')})">
    <a th:href="@{${currentUrl}(myparam=test)}">click here</a>
</div>

Next in Spring configuration:

@Bean
public Function<String, String> currentUrlWithoutParam() {
    return param ->   ServletUriComponentsBuilder.fromCurrentRequest().replaceQueryParam(param).toUriString();
}

For more "global" solution, I would try extending processor for attribute "th:href" or creating my own attribute. I'm not a thymeleaf expert, just facing similar problem.

回答2:

You can use URI builder, directly from Thymeleaf.

<span th:with="urlBuilder=${T(org.springframework.web.servlet.support.ServletUriComponentsBuilder).fromCurrentRequest()}"
      th:text="${urlBuilder.replaceQueryParam('p2', '32').toUriString()}">
</span>

For URL http://example.com/some/page?p1=11 prints out:

http://example.com/some/page?p1=11&p2=32

Explained:

• SpEL T operator is used for accessing ServletUriComponentsBuilder type.
• An instance created by factory method fromCurrentRequest is saved to urlBuilder variable.
• A param is added or replaced in the query string by replaceQueryParam method, and then the URL is built.

Pros:

• Safe solution.
• No trailing ? in case of empty query string.
• No extra bean in Spring context.

Cons:

• It is quite verbose.

! Be aware that solution above creates one instance of the builder. This means that the builder cannot be reused because it still modifies a single URL. For multiple URLs on a page you have to create multiple builders, like this:

<span th:with="urlBuilder=${T(org.springframework.web.servlet.support.ServletUriComponentsBuilder)}">
    <span th:text="${urlBuilder.fromCurrentRequest().replaceQueryParam('p2', 'whatever').toUriString()}"></span>
    <span th:text="${urlBuilder.fromCurrentRequest().replaceQueryParam('p3', 'whatever').toUriString()}"></span>
    <span th:text="${urlBuilder.fromCurrentRequest().replaceQueryParam('p4', 'whatever').toUriString()}"></span>
</span>

For http://example.com/some/page prints:

http://example.com/some/page?p2=whatever 
http://example.com/some/page?p3=whatever     
http://example.com/some/page?p4=whatever

回答3:

th:href="@{/your/link?parameter=__${appendParameter}__}"

回答4:

According to the docs you can specify all parameters

th:href="@{http://example.com/some/page(p1=11,p2=32)}"

You can use expressions to get values:

th:href="@{http://example.com/some/page(p1=11,p2=${someid})}"

回答5:

This will work for you, even in Unicode:

 <ul class="pagination">
                <li th:if="${currentPage > 1}"><a th:href="'/search?key=' + ${param.key[0]} + '&amp;page=' +   ${currentPage-1}">Previous</a></li>

                      <li th:each="i : ${#numbers.sequence( 1, total+1)}" th:class="${i==currentPage}?active:''">
                            <a th:href="'/search?key=' + ${param.key[0]} + '&amp;page=' +   ${i}" th:inline="text">
                            [[${i}]] <span  class="sr-only">(current)</span>
                            </a>
                      </li>
                      <li><a th:if="${total + 1 > currentPage}" th:href="'/search?key=' + ${param.key[0]} + '&amp;page=' +   ${currentPage+1}">Next</a></li>
            </ul>

来源：https://stackoverflow.com/questions/27623405/thymeleaf-add-parameter-to-current-url