com.github.bordertech.wcomponents

Interface Headers

All Known Implementing Classes:

HeadersImpl

public interface Headers

WComponents can use this interface to communicate "global" or "shared" items to the server. Examples are lines in the html/head element. It also allows for extra attributes on the html element itself.

It is important to note that "headlines" must be added in the preparePaint phase. Headlines adding in serviceRequest will be lost because the headers are reset at the start of preparePaint. Adding headlines in the paint phase is too late as the headers have already been written. Note also that it would be possible to make the adding of headlines work for the paint phase, but at the expense of requiring the entire body of the page to be cached.

Since:

1.0.0

Author:

James Gifford, Martin Shevchenko

Field Summary

Fields

Modifier and Type	Field and Description
static String	CSS_HEADLINE CSS headline.
static String	JAVASCRIPT_HEADLINE Javascript headline.
static String	UNTYPED_HEADLINE Untyped headline.

Method Summary

Modifier and Type	Method and Description
void	addHeadLine(String aLine) Records a "shared" line for inclusion in the output.
void	addHeadLine(String type, String aLine) Records a "shared" line (of a specified type) for inclusion in the output.
void	addUniqueHeadLine(String aLine) Records a line for inclusion in the html/head, if it has not already been included.
void	addUniqueHeadLine(String type, String aLine) Records a "shared" line (of a specified type) for inclusion in the output, if it has not already been included.
String	getContentType() Get the content type (usually text/html).
List	getHeadLines()
List	getHeadLines(String type) Get the head lines, of a specified type.
void	reset() Called by the servlet between service requests.
void	setContentType(String type) Set the content type (usually text/html).

Field Detail

UNTYPED_HEADLINE

static final String UNTYPED_HEADLINE

Untyped headline.

See Also:

Constant Field Values

JAVASCRIPT_HEADLINE

static final String JAVASCRIPT_HEADLINE

Javascript headline.

See Also:

Constant Field Values

CSS_HEADLINE

static final String CSS_HEADLINE

CSS headline.

See Also:

Constant Field Values

Method Detail

reset

void reset()

Called by the servlet between service requests.

addHeadLine

void addHeadLine(String aLine)

Records a "shared" line for inclusion in the output.

Parameters:

aLine - the line to add.

addHeadLine

void addHeadLine(String type,
                 String aLine)

Records a "shared" line (of a specified type) for inclusion in the output.

Parameters:

type - the type of line to add.

aLine - the line to add.

addUniqueHeadLine

void addUniqueHeadLine(String aLine)

Records a line for inclusion in the html/head, if it has not already been included.

Parameters:

aLine - the line to add.

addUniqueHeadLine

void addUniqueHeadLine(String type,
                       String aLine)

Records a "shared" line (of a specified type) for inclusion in the output, if it has not already been included.

An example of where this is useful is for adding shared JavaScript code.

Parameters:

type - the type of line to add.

aLine - the line to add.

getHeadLines

List getHeadLines()

Returns:

the "un-typed" head lines.

getHeadLines

List getHeadLines(String type)

Get the head lines, of a specified type.

Parameters:

type - the type of headlines to return.

Returns:

the head lines, of a specified type

getContentType

String getContentType()

Get the content type (usually text/html).

Returns:

the content mime type.

setContentType

void setContentType(String type)

Set the content type (usually text/html).

Parameters:

type - The content type to set on the response.