com.google.template.soy.data

Class SoyAbstractCachingValueProvider

java.lang.Object

com.google.template.soy.data.SoyAbstractCachingValueProvider

All Implemented Interfaces:

SoyValueProvider

Direct Known Subclasses:

SoyFutureValueProvider

public abstract class SoyAbstractCachingValueProvider
extends Object
implements SoyValueProvider

A SoyValueProvider that lazily computes and caches its value.

SoyAbstractCachingValueProvider is thread-safe, but in a race condition, may compute its value twice.

Important: Do not use outside of Soy code (treat as superpackage-private).

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SoyAbstractCachingValueProvider.ValueAssertion A mechanism to plug in assertions on the computed value that will be run the first time the value is computed.

Constructor Summary

Constructors

Constructor and Description
SoyAbstractCachingValueProvider()

Method Summary

Modifier and Type	Method and Description
void	addValueAssertion(SoyAbstractCachingValueProvider.ValueAssertion assertion) Registers a SoyAbstractCachingValueProvider.ValueAssertion callback with this caching provider.
protected abstract SoyValue	compute() Implemented by subclasses to do the heavy-lifting for resolving.
int	hashCode()
boolean	isComputed() Returns true if the caching provider has already been calculated.
RenderResult	renderAndResolve(LoggingAdvisingAppendable appendable, boolean isLast) Renders this value to the given LoggingAdvisingAppendable, possibly partially.
SoyValue	resolve() Usually, this method is a no-op that simply returns this object.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.google.template.soy.data.SoyValueProvider

status

Constructor Detail

SoyAbstractCachingValueProvider

public SoyAbstractCachingValueProvider()

Method Detail

resolve

public final SoyValue resolve()

Description copied from interface: SoyValueProvider

Usually, this method is a no-op that simply returns this object. However, if this value needs to be resolved at usage time, then this method resolves and returns the resolved value.

Specified by:

resolve in interface SoyValueProvider

Returns:

The resolved value.

renderAndResolve

public RenderResult renderAndResolve(LoggingAdvisingAppendable appendable,
                                     boolean isLast)
                              throws IOException

Description copied from interface: SoyValueProvider

Renders this value to the given LoggingAdvisingAppendable, possibly partially.

This should render the exact same content as resolve().render(Appendable) but may optionally detach part of the way through rendering. Note, this means that this method is stateful and if it returns something besides RenderResult.done() then the next call to this method will resume rendering from the previous point.

Specified by:

renderAndResolve in interface SoyValueProvider

Parameters:

appendable - The appendable to render to.

isLast - True if this is definitely the last time this value will be rendered. Used as a hint to implementations to not optimize for later calls (for example, by storing render results in a buffer for faster re-renders). The value of this parameter should not affect behavior of this method, only performance.

Returns:

A RenderResult that describes whether or not rendering completed. If the returned result is not done, then to complete rendering you must call this method again.

Throws:

IOException - If the appendable throws an IOException

hashCode

public int hashCode()

Overrides:

hashCode in class Object

isComputed

public final boolean isComputed()

Returns true if the caching provider has already been calculated.

addValueAssertion

public void addValueAssertion(SoyAbstractCachingValueProvider.ValueAssertion assertion)

Registers a SoyAbstractCachingValueProvider.ValueAssertion callback with this caching provider.

compute

protected abstract SoyValue compute()

Implemented by subclasses to do the heavy-lifting for resolving.