Replace tag in Apache velocity in java
Question
Haven't used Apache velocity , but in current project, we use this library to populate data into templates.
would like to ask if it is possible to replace tag inside template, using Velocity ?
I have such template:
<head>
<link href="conf/templates/template_style.css" rel="stylesheet" type="text/css"/>
</head>
<p>
<span class="mention" data-id="295" data-value="${AutumnExams}">
<span contenteditable="false">${AutumnExams}</span>
</span>
</p>
and using such code:
private String applyDynamicContent(String templateHtmlData, List<DynamicContentPart> dynamicContentParts) throws ParseException {
if (!dynamicContentParts.isEmpty()) {
RuntimeServices rs = RuntimeSingleton.getRuntimeServices();
SimpleNode sn = rs.parse(new StringReader(templateHtmlData), "Template body");
Template template = new Template();
template.setRuntimeServices(rs);
template.setData(sn);
template.initDocument();
VelocityContext context = createVelocityContext(null, null);
dynamicContentParts.forEach(dContent -> context.put(dContent.getPlaceholder(), dContent.getContent()));
StringWriter writer = new StringWriter();
template.merge(context, writer);
return writer.toString();
}
return templateHtmlData;
}
I am replacing only: ${AutumnExams} placeholders. But is there any possibility to replace the whole SPAN for example based on data-value="${AutumnExams}"
I have 1-hour experience with velocity lib , so would appreciate help with code.
2 answers
solution1
0 2018-09-03 20:56:30
To replace the entire tag you would need to use the Velocity if condition ( more info at this page ) based on a parameter that you insert in the model. That parameter can then be based on a condition in the backend.
For example, if you want to have two versions of the span tag based on a boolean "foo" variable use the following code:
#if( $foo )
<span class="mention" data-id="295" data-value="${AutumnExams}">
<span contenteditable="false">${AutumnExams}</span>
</span>
#else
<!-- second version of span -->
#end
solution2
0 2018-09-07 13:43:02
What @gmcontessa said is correct, you will need to use the if-check on your span field. Easiest would be to check if the value isn't null and then just replace it in your span:
#if ($!AutumnExams)
<span class="mention" data-id="295" data-value="$!AutumnExams">
<span contenteditable="false">$!AutumnExams</span>
</span>
#end
The main reason for using $! is to check if your variable has a value or not and if it doesn't it will just print an empty string. When used with an if-check it returns false if the variable is blank.
Also if you want to run a specific if-check on what the value of that velocity variable is you can do this:
#if ("$!AutumnExams" == "Maths")
<span class="mention" data-id="295" data-value="$!AutumnExams">
<span contenteditable="false">Maths</span>
</span>
#else
##Code here
#end
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