public static interface JxltEngine.Template
The source text is parsed considering each line beginning with '$$' (as default pattern) as JEXL script code and all others as Unified JEXL expressions; those expressions will be invoked from the script during evaluation and their output gathered through a writer. It is thus possible to use looping or conditional construct "around" expressions generating output.
For instance:$$ for(var x : [1, 3, 5, 42, 169]) { $$ if (x == 42) { Life, the universe, and everything $$ } else if (x > 42) { The value $(x} is over forty-two $$ } else { The value ${x} is under forty-two $$ } $$ }
Will evaluate as:
The value 1 is under forty-two The value 3 is under forty-two The value 5 is under forty-two Life, the universe, and everything The value 169 is over forty-two
During evaluation, the template context exposes its writer as '$jexl' which is safe to use in this case. This allows writing directly through the writer without adding new-lines as in:
$$ for(var cell : cells) { $jexl.print(cell); $jexl.print(';') }
A template is expanded as one JEXL script and a list of template expressions; each template expression is being replaced in the script by a call to jexl:print(expr) (the expr is in fact the expr number in the template). This integration uses a specialized JexlContext (TemplateContext) that serves as a namespace (for jexl:) and stores the template expression array and the writer (java.io.Writer) that the 'jexl:print(...)' delegates the output generation to.
Modifier and Type | Method and Description |
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String |
asString()
Recreate the template source from its inner components.
|
void |
evaluate(JexlContext context,
Writer writer)
Evaluates this template.
|
void |
evaluate(JexlContext context,
Writer writer,
Object... args)
Evaluates this template.
|
String[] |
getParameters()
Gets the list of parameters expected by this template.
|
Map<String,Object> |
getPragmas()
Gets this script pragmas.
|
Set<List<String>> |
getVariables()
Gets the list of variables accessed by this template.
|
JxltEngine.Template |
prepare(JexlContext context)
Prepares this template by expanding any contained deferred TemplateExpression.
|
String asString()
void evaluate(JexlContext context, Writer writer)
context
- the context to use during evaluationwriter
- the writer to use for outputvoid evaluate(JexlContext context, Writer writer, Object... args)
context
- the context to use during evaluationwriter
- the writer to use for outputargs
- the argumentsJxltEngine.Template prepare(JexlContext context)
context
- the context to prepare againstSet<List<String>> getVariables()
This method will visit all nodes of the sub-expressions and extract all variables whether they are written in 'dot' or 'bracketed' notation. (a.b is equivalent to a['b']).
String[] getParameters()
Map<String,Object> getPragmas()
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