Module snippetory.core

Package org.jproggy.snippetory.spi

Interface Format

All Known Subinterfaces:

VoidFormat

All Known Implementing Classes:

CaseFormatter.Camelize, CaseFormatter.FirstUpper, CaseFormatter.Lower, CaseFormatter.StringFormat, CaseFormatter.Upper, CropFormat, DateFormatter.DateFormatWrapper, DefaultFormat, NullFormat, NumFormatter.DecimalFormatWrapper, NumFormatter.ToStringFormat, PadFormat, PropertyFormat, SimpleFormat, ToggleFormatter.ToggleFormat, ValuesFormat

public interface Format

The format allows one to encapsulate and reuse portions of view logic in a simple and generic manner.

Format definition in template file

Formats are activated by a single attribute, that's evaluated by a FormatFactory, that parses this definition, found within the template file, in order to create an appropriate Format. However, before creating the format itself there is another step to take: The FormatFactory returns a FormatConfiguration which takes additional parameters, called sub-attributes. Sub attributes have the form <main-attribute>.<sub-attribute> and directly follow the main attribute. For instance:

stretch="20" stretch.align="left"

Sub-attributes are implemented as bean properties of the FormatConfiguration implementation:

  enum Alignment {left, right};
  public void setAlign(Alignment value) {..
 

This mechanism provides support for numbers, boolean, enums, and strings. Alternatively, especially when the attributes are not known at build time, this can be done by implementing DynamicAttributes instead. However, the separation of Format and FormatConfiguration is for advanced state handling and validation of the configuration. For most Formats extending SimpleFormat makes things much simpler by combining both.

Binding data to formats at runtime

In order to bind data to a format at runtime you have to implement VoidFormat and of course you've to take care for handling the state appropriately. Returning a new instance per call of FormatConfiguration.getFormat(org.jproggy.snippetory.util.TemplateNode) will do the job.

Author:

B. Ebertz

See Also:

Official documentation on formats, Extending the platform, FormatFactory, FormatConfiguration, SimpleFormat, VoidFormat

Method Summary

Modifier and Type	Method	Description
void	clear(TemplateNode location)	Resets the state of the format to initialization value.
Object	format(TemplateNode location, Object value)	Will only be called for supported values.
static void	register(String name, FormatFactory value)
boolean	supports(Object value)	Many formats only apply to a special type or even specific values.

Method Detail

register

static void register(String name,
                     FormatFactory value)

format

Object format(TemplateNode location,
              Object value)

Will only be called for supported values.

Parameters:

location - gives some additional information to this call like the target encoding

value - will be turned into character data

Returns:

value as character data. So either a String, a StringBuilder or EncodedData

supports

boolean supports(Object value)

Many formats only apply to a special type or even specific values. The format method will only be called for supported values

clear

void clear(TemplateNode location)

Resets the state of the format to initialization value. As most formats are state-less they can safely ignore this method.

Parameters:

location - In some cases state is bound to specific nodes