de.caff.templ

Interface ValueProvider

public interface ValueProvider

Interface for resolving template values.

Since:

April 03, 2026

Author:

Rammi

Method Summary

Modifier and Type	Method and Description
static ValueProvider	fromMapping(java.lang.String tag, java.lang.String value) Create a value provider which just handles one tag-value pair.
static ValueProvider	fromMapping(java.lang.String k1, java.lang.String v1, java.lang.String k2, java.lang.String v2) Create a value provider which just handles two tag-value pairs.
static ValueProvider	fromMapping(java.lang.String k1, java.lang.String v1, java.lang.String k2, java.lang.String v2, java.lang.String k3, java.lang.String v3, java.lang.String... moreTagsAndValues) Create a value provider which just handles three or more tag-value pairs.
static ValueProvider	multi(java.util.function.Function<java.lang.String,java.lang.Iterable<ValueProvider>> multiFunction) Create a value provider which does only handle multi-values.
java.lang.Iterable<ValueProvider>	multiValue(java.lang.String tag) Get the value providers for a multiple insertion.
static ValueProvider	parentWrap(ValueProvider parentProvider, ValueProvider childProvider) Wrap a provider with a parent provider.
java.lang.String	value(java.lang.String tag) Get the value which is inserted for a given tag.
default ValueProvider	withParent(ValueProvider parentProvider) Wrap this provider with the given parent provider.

Method Detail

value

@Nullable
java.lang.String value(@NotNull
                                 java.lang.String tag)

Get the value which is inserted for a given tag.

Parameters:

tag - template tag

Returns:

associated value, or null if the tag is unresolvable

multiValue

@Nullable
java.lang.Iterable<ValueProvider> multiValue(@NotNull
                                                       java.lang.String tag)

Get the value providers for a multiple insertion.

Parameters:

tag - template tag for the insertion

Returns:

value providers for the multiple insertion, or null if the tag is unresolvable

withParent

@NotNull
default ValueProvider withParent(@NotNull
                                          ValueProvider parentProvider)

Wrap this provider with the given parent provider.

The returned provider will first try to resolve items with this provider, the fall back to the parent if this provider cannot resolve a tag.

This allows to define a hierarchy of providers.

Parameters:

parentProvider - parent provider for fallback evaluation

Returns:

wrapped provider as described

See Also:

parentWrap(ValueProvider, ValueProvider)

parentWrap

@NotNull
static ValueProvider parentWrap(@NotNull
                                         ValueProvider parentProvider,
                                         @NotNull
                                         ValueProvider childProvider)

Wrap a provider with a parent provider.

The returned provider will first try to resolve a tag using the child provider, and try the parent provider if the child cannot resolve the item.

This allows to define a hierarchy of providers.

Parameters:

parentProvider - parent provider used as fallback

childProvider - child provider used first

Returns:

wrapped provider as described

See Also:

withParent(ValueProvider)

fromMapping

@NotNull
static ValueProvider fromMapping(@NotNull
                                          java.lang.String tag,
                                          @NotNull
                                          java.lang.String value)

Create a value provider which just handles one tag-value pair.

Parameters:

tag - the only possible tag

value - the associated value

Returns:

value provider which cannot handle multi-values, and only one tag

fromMapping

@NotNull
static ValueProvider fromMapping(@NotNull
                                          java.lang.String k1,
                                          @NotNull
                                          java.lang.String v1,
                                          @NotNull
                                          java.lang.String k2,
                                          @NotNull
                                          java.lang.String v2)

Create a value provider which just handles two tag-value pairs.

Parameters:

k1 - the first possible tag

v1 - the value associated with the first tag

k2 - the second possible tag

v2 - the value associated with the second tag

Returns:

value provider which cannot handle multi-values, and only two keys

fromMapping

@NotNull
static ValueProvider fromMapping(@NotNull
                                          java.lang.String k1,
                                          @NotNull
                                          java.lang.String v1,
                                          @NotNull
                                          java.lang.String k2,
                                          @NotNull
                                          java.lang.String v2,
                                          @NotNull
                                          java.lang.String k3,
                                          @NotNull
                                          java.lang.String v3,
                                          @NotNull
                                          java.lang.String... moreTagsAndValues)

Create a value provider which just handles three or more tag-value pairs.

Parameters:

k1 - the first possible tag

v1 - the value associated with the first tag

k2 - the second possible tag

v2 - the value associated with the second tag

k3 - the third possible tag

v3 - the value associated with the third tag

moreTagsAndValues - more tags (even positions) and values (odd positions), an even number of var args is required

Returns:

value provider which cannot handle multi-values, and only the given keys

multi

@NotNull
static ValueProvider multi(@NotNull
                                    java.util.function.Function<java.lang.String,java.lang.Iterable<ValueProvider>> multiFunction)

Create a value provider which does only handle multi-values.

Parameters:

multiFunction - multi-value resolve function

Returns:

value provider which does not resolve single values, but resolves multi-values with multiFunction