FormatRepository (BandM metatools API doc)

java.lang.Object
- eu.bandm.tools.format.FormatRepository<K>

```
public abstract class FormatRepository<K extends Serializable>
extends Object
```
A map-like store for formats with serialized resource backing store and on-demand computation.
The intended use is to bundle constant formats bound to static final fields of a class C. If no further action is taken, these are computed at the time class C is loaded. In order to precompute them offline, so that loading class C merely deserializes the formats, do the following:
Declare a static final FormatRepository in class C with context set to C.
Declare static final formats in C initialized by calls to cache(K).
Load class C to compute the formats.
Call store(File) to store the computed formats.
Install the resulting file to the location from where the class is loaded.
For using this class you have to derive a sub-class and implement the only abstract method, toFormat(K), which carries out the effective generation of format objects.
A practical way is to use java.lang.String as the K parameter, and call a parser (like metajava FormatClosure to derive the format objects from the character sequence forming the key.

This class can also be used in conjunction with dynamically produced formats. The caching functionality is completely available in the dynamic case. But beware that persistent storage of a dynamic collection of formats is only efficient if the actual members do not vary too much from one run of the application to the other, or if a superset of potential members can be approximated ahead of time.

Field Summary

Fields
Modifier and Type	Field and Description
`protected Class<?>`	`context`
`protected String`	`filename` The resource filename.
`protected Map<K,Format>`	`formats` The computed formats.
`protected String`	`name`
`protected boolean`	`stored` Indicates whether the current state has been successfully stored.
`protected static File`	`wd`

Constructor Summary

Constructors
Constructor and Description

FormatRepository(Class<?> context, String name)
Creates a new repository.

Constructors
Constructor and Description
`FormatRepository(Class<?> context, String name)` Creates a new repository.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`Format`	`cache(K key)` Computes or retrieves the format for a key.
`void`	`clear()` Removes all computed or loaded formats.
`boolean`	`store()` Stores computed formats relative to the current working directory.
`boolean`	`store(File directory)` Stores computed formats relative to a given directory.
`protected abstract Format`	`toFormat(K key)` Computes the format for a key.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - context
```
protected final Class<?> context
```
  - name
```
protected final String name
```
  - filename
```
protected final String filename
```
    The resource filename. Always set to String.valueOf(context) + "." + name
  - formats
```
protected final Map<K extends Serializable,Format> formats
```
    The computed formats.
  - stored
```
protected boolean stored
```
    Indicates whether the current state has been successfully stored.
  - wd
```
protected static final File wd
```
- Constructor Detail
  - FormatRepository
```
public FormatRepository(Class<?> context,
                        String name)
```
    Creates a new repository. The resource name (i.e. filename) for this repository is composed from a context class and a specific name. If the resource is available, the stored formats are loaded.
    
    Parameters:
    
    context - the context class.
    
    name - the name.
- Method Detail
  - cache
```
public Format cache(K key)
```
    Computes or retrieves the format for a key. If the format has already been computed or loaded, it is retrieved. Otherwise, it is computed with toFormat(K).
  - clear
```
public void clear()
```
    Removes all computed or loaded formats.
  - toFormat
```
protected abstract Format toFormat(K key)
```
    Computes the format for a key.
  - store
```
public boolean store()
```
    Stores computed formats relative to the current working directory.
  - store
```
public boolean store(File directory)
```
    Stores computed formats relative to a given directory. Creates a file directory/filename. Must be installed into the class tree manually in order to be loaded.
    
    Parameters:
    
    directory - the directory. It is created if it does not exists.
    
    Returns:
    
    true if successful.

Class FormatRepository<K extends Serializable>

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

context

name

filename

formats

stored

wd

Constructor Detail

FormatRepository

Method Detail

cache

clear

toFormat

store

store