Define and insert Thymeleaf fragments in TEXT templates

I'm trying to create email templates in both plain text and HTML with Thymeleaf. Because I don't want to duplicate the common parts I want to define these parts separately and insert them into the more specific templates.

It works for HTML, but for plain text variables in the common parts are not replaced:

HTML

common.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    </head>
    <body>
        <div th:fragment="header">
            <p>
                Hello, [( ${name} )]
            </p>
        </div>
        <div th:fragment="footer">
            <p>
                Bye.
            </p>
        </div>
    </body>
</html>

specific.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    </head>
    <body>
        <div th:replace="html/common::header"></div>
        <p>
            <a th:href="${myLink}">[( ${myLink} )]</a>
        </p>
        <div th:replace="html/common::footer"></div>
    </body>
</html>

Plain text

header.txt
```
Hello ${name}
```
footer.txt
```
Bye
```

specific.txt

[( ~{text/header} )]
[( ${myLink} )]
[( ~{text/footer} )]

Result

It all works well for HTML but for the plain text version the ${name} variable from the inserted header.txt template is not replaced:

Hello, [#th:block th:utext="${name}"][/th:block]

    http://example.com

Bye.

The HTML result looks correct:

<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    </head>
    <body>
        <div>
            <p>
                Hello, name-value
            </p>
        </div>
        <p>
            <a href="http://example.com">http://example.com</a>
        </p>
        <div>
            <p>
                Bye.
            </p>
        </div>
    </body>
</html>

My questions

Is there an elegant solution for the plain text version?
Is there a way to define and use fragments also for textual Thymeleaf templates?
Any general recommendations, as I'm only starting to use Thymeleaf?

Solution

Variables in the Plain Text Version

For the plain text issue, you can use the [#th:block] syntax.

Specifically, instead of using this in your specific.txt:

[( ~{text/header} )]

you can use this:

[#th:block th:replace="text/header"][/th:block]

Also, in the header.txt file, instead of using this:

Hello ${name}

you need to use this:

Hello [( ${name} )]

This is expression inlining - which you have already used - and is presented here, for reference.

Some additional examples of the [#th:block] syntax are presented here.

Defining and Using Fragments for Text

You might think that the [#th:block] syntax would now allow us to use fragments, in a similar way to the HTML approach. For example, something like this:

DOES NOT WORK:
[#th:block th:replace="text/common :: header"][/th:block]

together with a common.txt fragment like this:

ALSO DOES NOT WORK:
[#th:block th:fragment="header"]
Hello, [( ${name} )]
[/th:block]

If you try this, you will get the following error:

java.lang.IllegalArgumentException: Template selectors cannot be specified for a template using a TEXT template mode: template insertion operations must be always performed on whole template files, not fragments

General Comments

The only other thing I would mention here, if you have not already seen or used it, is parameterized fragments. They can make HTML fragments more flexible and re-usable.