Rendering a multiline line in Timeleaf

Question

In the variant of this question , I want to display a multiline row in an HTML table using Thymeleaf.

That is, how do I convert a string like

Cronut fixie tousled migas. Whatever neutra offal fanny pack, photo booth kitsch bespoke hammock swag. Keffiyeh yuccie meditation mustache cornhole paleo. 

in

 <table class="table"> <tr> <td>Cronut fixie tousled migas.</td> </tr> <tr> <td>Whatever neutra offal fanny pack, photo booth kitsch bespoke hammock swag.</td> </tr> <tr> <td>Keffiyeh yuccie meditation mustache cornhole paleo.</td> </tr> </table> 

Answer 1

With the string contained in the model.text model model.text , a possible solution (when using the Spring dialect) is the following:

 <table> <tr th:each="line : ${#strings.arraySplit(model.text, T(org.apache.commons.lang3.StringUtils).LF)}"> <td th:text="${line}"></td> </tr> </table> 

The reason for using T(org.apache.commons.lang3.StringUtils).LF instead of just \n is because (as also described in this answer ). SpEL speeds up the backslash and then decides to split by 'n' letters instead of newlines.

Of course, you should also consider the solution of simply breaking the string into an array directly in the controller (i.e. using simple Java).

Answer 2

I originally posted this answer to a previous SO question , but this one seems to pop up too. I changed it to display the table instead of newlines.

This can be done using a special dialect and an attribute processor to handle this without a lot of built-in SpEl or hacks.

Creating a custom attribute processor

 public class NewlineAttrProcessor extends AbstractUnescapedTextChildModifierAttrProcessor { public NewlineAttrProcessor() { super("nl2br"); } @Override protected String getText(Arguments arguments, Element element, String attributeName) { final Configuration configuration = arguments.getConfiguration(); final IStandardExpressionParser parser = StandardExpressions.getExpressionParser(configuration); final String attributeValue = element.getAttributeValue(attributeName); final IStandardExpression expression = parser.parseExpression(configuration, arguments, attributeValue); final String value = (String)expression.execute(configuration, arguments); final String[] lines = StringUtils.split(value, "\n"); return "<table><td>" + StringUtils.join(lines, "</td><td>") + "</td></table>"; } @Override public int getPrecedence() { return 10000; } } 

You need to extend the AbstractUnescapedTextChildModifierAttrProcessor processor, otherwise you will get html entity tags for <table>...</table> and you will not actually get HTML.

Create custom dialect

To implement a custom dialect, you will need a dialect class:

 public class MyCustomDialect extends AbstractDialect { @Override public String getPrefix() { return "cd"; } @Override public Set<IProcessor> getProcessors() { final Set<IProcessor> processors = new HashSet<>(); processors.add(new NewlineAttrProcessor()); return processors; } } 

The return value of the getPrefix method is what you could use to call any custom processors you make. For example, Thimeleaf uses th . The user processor that we implemented above this is looking for nl2br , so you must use the cd:nl2br instead of th:text to call it.

Register a new dialect

In your main class, you just need to create @Bean , which will return a new instance of your dialect class.

 @SpringBootApplication public class MyApplication { public static void main(String[] args) { SpringApplication.run(MyApplication.class, args); } @Bean public MyCustomDialect myCustomDialect() { return new MyCustomDialect(); } } 

Using a custom processor

Finally, in your template file you will have the following HTML tag:

<div cd:nl2br="${myObject.myField}">MY MULTILINE FIELD</div>

For a more detailed guide on implementing custom dialects, I recommend the Thymeleaf docs:

• Thymeleaf extension in 5 minutes
• Thymeleaf extension in 5 minutes