Module io.jstach.opt.jmustache

Package io.jstach.opt.jmustache

Class JMustacheRenderer

java.lang.Object

io.jstach.opt.jmustache.JMustacheRenderer

All Implemented Interfaces:

JStachioExtension, JStachioExtensionProvider, JStachioFilter

@MetaInfServices(JStachioExtension.class)
public class JMustacheRenderer
extends Object

Use JMustache instead of JStachio for rendering. The idea of this extension is to allow you to edit Mustache templates in real time without waiting for the compile reload cycle.

You are probably asking yourself why do I need JMustache if I have JStachio? Unfortunately JStachio needs the annotation processor to run every time a template is changed!. While there are incremental compilers like Eclipse that do support incrementally compiling annotations they are often not triggered via editing resources. Furthermore incremental compilation often just doesn't work.

Enter JMustache. Through reflection you can edit your templates while an application is running. Luckily JMustache and JStachio are almost entirely compatible especially through this extension which configures JMustache to act like JStachio. Even JStacheLambda will work.

The only major compatibility issue is that JMustache currently does not support mustache inheritance (parents and blocks)!

If this extension is enabled which it is by default if the ServiceLoader finds it JMustache will be used when a runtime filtered rendering call is made (see JStachio).

How this works is this extension is a filter that checks to see if the statically generated renderer (template) can render and that its template is up-to-date. If it is not then JMustache will use the template meta data to construct its own template and then execute it. In some cases the annotation processor does not even have to run for this to work (see Templates.getInfoByReflection(Class).

Strongly recommended you disable this in production via JSTACHIO_JMUSTACHE_DISABLE or use

Author:

agentgt

See Also:

• JStachio

Nested Class Summary

Nested classes/interfaces inherited from interface io.jstach.jstachio.spi.JStachioFilter

JStachioFilter.FilterChain

Field Summary

Fields

Modifier and Type	Field	Description
static final String	JSTACHIO_JMUSTACHE_DISABLE	Property key to disable jmustache.
static final String	JSTACHIO_JMUSTACHE_SOURCE_PATH	Property key of where jmustache will try to load template files.

Constructor Summary

Constructors

Constructor	Description
JMustacheRenderer()	No-arg constructor for ServiceLoader

Method Summary

Modifier and Type	Method	Description
JStachioFilter.FilterChain	filter(TemplateInfo template, JStachioFilter.FilterChain previous)	Advises or filters a previously created filter.
void	init(JStachioConfig config)	Called before the extensions are used but after JStachioExtensionProvider.provideConfig().
JMustacheRenderer	prefix(@Nullable String prefix)	A prefix to add to the output to know that JMustache is being used.
final @NonNull JStachioFilter	provideFilter()	Provide a filter or not.
JMustacheRenderer	sourcePath(String sourcePath)	Sets the relative to the project sourcePath for runtime lookup of templates.
JMustacheRenderer	suffix(@Nullable String suffix)	A suffix to append to the output to know that JMustache is being used.
JMustacheRenderer	use(boolean flag)	Enables JMustache

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface io.jstach.jstachio.spi.JStachioExtensionProvider

provideConfig, provideTemplateFinder

Methods inherited from interface io.jstach.jstachio.spi.JStachioFilter

filter, order

Field Details

JSTACHIO_JMUSTACHE_SOURCE_PATH

public static final String JSTACHIO_JMUSTACHE_SOURCE_PATH

Property key of where jmustache will try to load template files. Default is src/main/resources.

See Also:

• Constant Field Values

JSTACHIO_JMUSTACHE_DISABLE

public static final String JSTACHIO_JMUSTACHE_DISABLE

Property key to disable jmustache. Default is false.

See Also:

• Constant Field Values

Constructor Details

JMustacheRenderer

public JMustacheRenderer()

No-arg constructor for ServiceLoader

Method Details

use

public JMustacheRenderer use(boolean flag)

Enables JMustache

Parameters:

flag - true enables

Returns:

return this for builder like config

prefix

public JMustacheRenderer prefix(@Nullable String prefix)

A prefix to add to the output to know that JMustache is being used.

Parameters:

prefix - string to prefix output

Returns:

return this for builder like config

suffix

public JMustacheRenderer suffix(@Nullable String suffix)

A suffix to append to the output to know that JMustache is being used.

Parameters:

suffix - string to suffix output

Returns:

return this for builder like config

sourcePath

public JMustacheRenderer sourcePath(String sourcePath)

Sets the relative to the project sourcePath for runtime lookup of templates. By default is src/main/resources.

Parameters:

sourcePath - by default is src/main/resources

Returns:

sourcePath should not be null

init

public void init(JStachioConfig config)

Description copied from interface: JStachioExtensionProvider

Called before the extensions are used but after JStachioExtensionProvider.provideConfig(). See JStachioExtensionProvider.provideConfig() on how the config is consolidated to a single config.

Parameters:

config - the composite config never null

filter

public JStachioFilter.FilterChain filter(TemplateInfo template,
 JStachioFilter.FilterChain previous)

Description copied from interface: JStachioFilter

Advises or filters a previously created filter.

Specified by:

filter in interface JStachioFilter

Parameters:

template - info about the template

previous - the function returned early in the chain.

Returns:

an advised render function or often the previous render function if no advise is needed.

provideFilter

public final @NonNull JStachioFilter provideFilter()

Provide a filter or not. The final filter is a composite and becomes a filter chain. The implementation is a filter and provides itself.

Specified by:

provideFilter in interface JStachioExtensionProvider

Returns:

filter if this service provider provies one or null