org.mmbase.bridge.jsp.taglib
Class ContextReferrerTag

java.lang.Object
  javax.servlet.jsp.tagext.TagSupport
      javax.servlet.jsp.tagext.BodyTagSupport
          org.mmbase.bridge.jsp.taglib.ContextReferrerTag

All Implemented Interfaces:

Serializable, BodyTag, IterationTag, JspTag, Tag, TryCatchFinally

Direct Known Subclasses:

AbstractParamTag, BranchTag, CloudReferrerTag, CloudTag, ContextTag, EscaperTag, EscapeTag, HasPageTag, ImportTag, LeafConstraintsTag, ListReferrerTag, LogTag, PresentTag, QueryAddNodeTag, RemoveTag, TimerTag, TimeTag, ValidTag, WriteTag, XsltTag

public abstract class ContextReferrerTag
extends BodyTagSupport
implements TryCatchFinally

If you want to have attributes which obtain the value from a parameter or other context variable, or if you want to be able to refer to other tags, then your tag can extend from this one.

Version:

$Id: ContextReferrerTag.java 35869 2009-06-09 14:02:59Z michiel $

Author:

Michiel Meeuwissen

See Also:

ContextTag, Serialized Form

Field Summary

protected Attribute	contextId
static int	EVAL_BODY EVAL_BODY is EVAL_BODY_INCLUDE or EVAL_BODY_BUFFERED.
protected WriterHelper	helper The helper member is only used by 'Writer' extensions.
protected Attribute	id
protected ContextTag	pageContextTag
protected Attribute	referid
protected Attribute	writerid Which writer to use.

Fields inherited from class javax.servlet.jsp.tagext.BodyTagSupport

bodyContent

Fields inherited from class javax.servlet.jsp.tagext.TagSupport

pageContext

Fields inherited from interface javax.servlet.jsp.tagext.BodyTag

EVAL_BODY_BUFFERED, EVAL_BODY_TAG

Fields inherited from interface javax.servlet.jsp.tagext.IterationTag

EVAL_BODY_AGAIN

Fields inherited from interface javax.servlet.jsp.tagext.Tag

EVAL_BODY_INCLUDE, EVAL_PAGE, SKIP_BODY, SKIP_PAGE

Constructor Summary

ContextReferrerTag()

Method Summary

String	appendMoreParameters(String connector, String amp, StringBuffer buf) Deprecated.
void	doCatch(Throwable e)
int	doEndTag()
void	doFinally()
void	fillStandardParameters(Parameters p) Fill standard parameters like request, response, language and locale
Tag	findLoopOrQuery(String tagId, boolean exception) Find loop or query tag using an id
protected <C> C	findParentTag(Class<C> clazz, String id) Finds a parent tag by class and id.
<C> C	findParentTag(Class<C> clazz, String tagId, boolean exception) Finds a parent tag by class and id.
Writer	findWriter() Find the parent writer tag.
Writer	findWriter(boolean th) Find the parent writer tag.
Attribute	getAttribute(String attribute)
Attribute	getAttribute(String attribute, boolean interpretEmptyAsAbsent)
protected Boolean	getAttributeBoolean(String b) Like getAttributeValue but converts the result to a Boolean, and throws an exception if this cannot be done.
protected Integer	getAttributeInteger(String i) Like getAttributeValue but converts the result to an Integer, and throws an exception if this cannot be done.
protected Integer	getAttributeInteger(String i, int def)
String	getAttributeValue(String attribute) Deprecated. Call getAttribute in the set-method and 'toString(tag)' when using it. This is better for performance and makes sure the impl. works in all servlet containers.
ContentTag	getContentTag() Returns the content-tag in which this context-referrer is in, or a default (compatible with MMBase 1.6) if there is none.
ContextProvider	getContextProvider() Finds the parent context provider.
ContextTag	getContextTag() Finds the parent context tag.
protected Block	getCurrentBlock()
Locale	getDefaultLocale() Get the default locale which is set in mmbase.
protected Object	getEscapedValue(Object value) Returns the escaped value associated with this tag, but only if the escape attribute was set explicitly (so not when only inherited from content-tag).
FormTag	getFormTag(boolean excpetion, Attribute form) Get the surrounding form tag
String	getId()
Locale	getLocale() Get the locale which is defined by surrounding tags or the cloud
Locale	getLocaleFromContext() Get the locale which is defined by surrounding tags or the cloud
Object	getObject(String key) Gets an object from the Context.
Object	getObjectConditional(String key) Support '[key]?', which returns the object with name [key] if it is present, or simply null otherwise.
PageContext	getPageContext() Just exposes the (otherwise protected) pageContext member.
protected ContextTag	getPageContextTag() Returns the ContextTag first on the page
protected Query	getQuery(Attribute container) Implements a getQuery for QueryContainerReferrers
protected String	getReferid()
protected String	getString(String key) Gets an object from the Context, and returns it as a String.
protected static String	getTaglibVersion()
static PageContext	getThreadPageContext() Returns the pageContext which is stored on a trhead local for this request
TimeZone	getTimeZone() Get the timezone from the context or the timezone set in mmbase
Object	getWriterValue()
void	haveBody()
void	release() Release all allocated resources.
void	setContext(String c) Refer to a specific context.
void	setEscape(String e)
void	setId(String i)
void	setJspvar(String j)
void	setListdelimiter(String l) Set list delimiter
void	setPageContext(PageContext pc)
(package private) void	setPageContextOnly(PageContext pc)
void	setReferid(String r) ContextReferrers normally can have the attribute 'referid'.
void	setVartype(String t)
void	setWrite(String w)
void	setWriter(String w) Sets the writer attribute.

Methods inherited from class javax.servlet.jsp.tagext.BodyTagSupport

doAfterBody, doInitBody, doStartTag, getBodyContent, getPreviousOut, setBodyContent

Methods inherited from class javax.servlet.jsp.tagext.TagSupport

findAncestorWithClass, getParent, getValue, getValues, removeValue, setParent, setValue

Methods inherited from class java.lang.Object

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

Methods inherited from interface javax.servlet.jsp.tagext.Tag

getParent, setParent

Field Detail

EVAL_BODY

public static int EVAL_BODY

EVAL_BODY is EVAL_BODY_INCLUDE or EVAL_BODY_BUFFERED. It wants to be EVAL_BODY_INCLUDE, but because that often not works, it on default is EVAL_BODY_BUFFERED. This configurable constant might become deprecated, because it is a bit experimental.

pageContextTag

protected ContextTag pageContextTag

contextId

protected Attribute contextId

referid

protected Attribute referid

id

protected Attribute id

writerid

protected Attribute writerid

Which writer to use.

helper

protected final WriterHelper helper

The helper member is only used by 'Writer' extensions.

Constructor Detail

ContextReferrerTag

public ContextReferrerTag()

Method Detail

getTaglibVersion

protected static String getTaglibVersion()

setPageContextOnly

void setPageContextOnly(PageContext pc)

getThreadPageContext

public static PageContext getThreadPageContext()

Returns the pageContext which is stored on a trhead local for this request

Returns:

jsp pageContext

Since:

MMBase-1.8.5

getPageContext

public PageContext getPageContext()

Just exposes the (otherwise protected) pageContext member. Needed by some helper classes in the neighbourhood. Lacking concept of friends.

Returns:

JSP Page Context

getPageContextTag

protected ContextTag getPageContextTag()

Returns the ContextTag first on the page

Returns:

ContextTag of page

Since:

MMBase-1.7.4

setPageContext

public void setPageContext(PageContext pc)

Specified by:

setPageContext in interface Tag

Overrides:

setPageContext in class TagSupport

setReferid

public void setReferid(String r)
                throws JspTagException

ContextReferrers normally can have the attribute 'referid'. If a ContextReferrer has the 'id' attribute it registers its output in the surrounding Context. With 'referid' you can 'repeat' a tag which had the 'id' attribute.

Parameters:

r - referid value

Throws:

JspTagException - when parsing of attributes fails

setId

public void setId(String i)

Overrides:

setId in class TagSupport

getId

public String getId()

Overrides:

getId in class TagSupport

getReferid

protected String getReferid()
                     throws JspTagException

Throws:

JspTagException

findWriter

public Writer findWriter()
                  throws JspTagException

Find the parent writer tag. It also calls haveBody on this parent tag, so that this knows that it has a body. If a write-tag has a body, then on default it will not write itself, but only communicate itself tot the body's tags.

Returns:

Writer

Throws:

JspTagException - when parsing of attributes fails

findWriter

public Writer findWriter(boolean th)
                  throws JspTagException

Find the parent writer tag. It also calls haveBody on this parent tag, so that this knows that it has a body. If a write-tag has a body, then on default it will not write itself, but only communicate itself tot the body's tags.

Parameters:

th - if it has to throw an exception if the parent can not be found (default: yes).

Returns:

Writer

Throws:

JspTagException - when parsing of attributes fails

Since:

MMBase-1.6.2

setWriter

public void setWriter(String w)
               throws JspTagException

Sets the writer attribute.

Parameters:

w - unparsed attribute

Throws:

JspTagException - when parsing of attributes fails

doEndTag

public int doEndTag()
             throws JspTagException

Specified by:

doEndTag in interface Tag

Overrides:

doEndTag in class BodyTagSupport

Throws:

JspTagException

doFinally

public void doFinally()

Specified by:

doFinally in interface TryCatchFinally

doCatch

public void doCatch(Throwable e)
             throws Throwable

Specified by:

doCatch in interface TryCatchFinally

Throws:

Throwable

release

public void release()

Release all allocated resources.

Specified by:

release in interface Tag

Overrides:

release in class BodyTagSupport

setContext

public void setContext(String c)
                throws JspTagException

Refer to a specific context. With this you can refer to, and write in, another context then the direct parent (but is must be an ancestor). This is for analogy with other attributes like this.

Parameters:

c - name of specific context

Throws:

JspTagException - when parsing of attributes fails

getAttributeValue

public String getAttributeValue(String attribute)
                         throws JspTagException

Deprecated. Call getAttribute in the set-method and 'toString(tag)' when using it. This is better for performance and makes sure the impl. works in all servlet containers.

Call this function in your set-attribute function. It makes it possible for the user of the taglib to include ids of values stored in the context. The method replaces all occurrences of ${x} and $x, where x is a reference to a attribute value, possibly prefixed with context names. The end of the variable if determined by the closing bracket (${x}) or by the first non ContextIndentifierChar or end of string ($x). Simple arithmetic is possible with ${+...}, and since you can even use $-vars inside ${}, you can do in this way some arithmetic on variables.

Parameters:

attribute - name of attribute

Returns:

Value of attribute

Throws:

JspTagException - when parsing of attributes fails

getAttribute

public Attribute getAttribute(String attribute)
                       throws JspTagException

Parameters:

attribute - unparsed attribute

Returns:

Attribute

Throws:

JspTagException - when parsing of attributes fails

Since:

MMBase-1.6.1

getAttribute

public Attribute getAttribute(String attribute,
                              boolean interpretEmptyAsAbsent)
                       throws JspTagException

Throws:

JspTagException

Since:

MMBase-1.9

getAttributeBoolean

protected Boolean getAttributeBoolean(String b)
                               throws JspTagException

Like getAttributeValue but converts the result to a Boolean, and throws an exception if this cannot be done.

Parameters:

b - unparsed attribute

Returns:

boolean

Throws:

JspTagException - when parsing of attributes fails

getAttributeInteger

protected Integer getAttributeInteger(String i)
                               throws JspTagException

Like getAttributeValue but converts the result to an Integer, and throws an exception if this cannot be done. It the incoming string evaluates to an empty string, then it will return 0, unless the second optional parameter specifies another default value;

Parameters:

i - unparsed attribute

Returns:

integer value of attribute

Throws:

JspTagException - when parsing of attributes fails

getAttributeInteger

protected Integer getAttributeInteger(String i,
                                      int def)
                               throws JspTagException

Throws:

JspTagException

findParentTag

public <C> C findParentTag(Class<C> clazz,
                           String tagId,
                           boolean exception)
                throws JspTagException

Finds a parent tag by class and id. This is a base function for 'getContext', but it is handy in itself, so also available for extended classes.

Type Parameters:

C - type of the tag class

Parameters:

clazz - the class of the Tag to find.

tagId - the id of the Tag to find.

exception - if it has to throw an exception if the parent can not be found (default: yes).

Returns:

Parent tag

Throws:

JspTagException - when the parent tag is not found

Since:

MMBase-1.7

findLoopOrQuery

public Tag findLoopOrQuery(String tagId,
                           boolean exception)
                    throws JspTagException

Find loop or query tag using an id

Parameters:

tagId - the id of the Tag to find.

exception - if it has to throw an exception if the parent can not be found (default: yes).

Returns:

Tag

Throws:

JspTagException - when parent tag is not found

Since:

MMBase-1.8

findParentTag

protected final <C> C findParentTag(Class<C> clazz,
                                    String id)
                         throws JspTagException

Finds a parent tag by class and id. This is a base function for 'getContext', but it is handy in itself, so also available for extended classes.

Type Parameters:

C - type of the tag class

Parameters:

clazz - the class of the Tag to find.

id - the id of the Tag to find.

Returns:

Parent tag

Throws:

JspTagException - when parent tag is not found

Since:

MMBase-1.7

getContextProvider

public ContextProvider getContextProvider()
                                   throws JspTagException

Finds the parent context provider.

Returns:

ContextProvider

Throws:

JspTagException - when context provider is not found

Since:

MMBase-1.7

getContextTag

public ContextTag getContextTag()
                         throws JspTagException

Finds the parent context tag. In MMBase 1.7 and higher, normally you would like to use getContextProvider in stead.

Returns:

ContextTag

Throws:

JspTagException - when context provider is not found

getObject

public Object getObject(String key)
                 throws JspTagException

Gets an object from the Context.

Parameters:

key - key the object is stored under

Returns:

stored object

Throws:

JspTagException - when context provider is not found

getObjectConditional

public Object getObjectConditional(String key)
                            throws JspTagException

Support '[key]?', which returns the object with name [key] if it is present, or simply null otherwise. If not ends with ?, it simply behaves like getObject(String).

Parameters:

key - key the object is stored under

Returns:

stored object

Throws:

JspTagException - when context provider is not found

Since:

MMBase-1.8.1

getString

protected String getString(String key)
                    throws JspTagException

Gets an object from the Context, and returns it as a String. This is not always a simple 'toString'. For example a getString on a Node will return the number, which also uniquely identifies it. If the object is 'not present' then it returns an empty string.

Parameters:

key - key the string is stored under

Returns:

stored string

Throws:

JspTagException - when context provider is not found

getContentTag

public ContentTag getContentTag()
                         throws JspTagException

Returns the content-tag in which this context-referrer is in, or a default (compatible with MMBase 1.6) if there is none.

Returns:

ContextTag

Throws:

JspTagException - when parent tag is not found

Since:

MMBase-1.7

getLocale

public Locale getLocale()
                 throws JspTagException

Get the locale which is defined by surrounding tags or the cloud

Returns:

a locale when defined or otherwise the mmbase locale.

Throws:

JspTagException - when parent tag is not found

Since:

MMBase-1.7.1

getLocaleFromContext

public Locale getLocaleFromContext()
                            throws JspTagException

Get the locale which is defined by surrounding tags or the cloud

Returns:

a locale when defined or otherwise null

Throws:

JspTagException - when parent tag is not found

Since:

MMBase-1.8.1

getDefaultLocale

public Locale getDefaultLocale()

Get the default locale which is set in mmbase.

Returns:

default locale

Since:

MMBase-1.8.1

getTimeZone

public TimeZone getTimeZone()

Get the timezone from the context or the timezone set in mmbase

Returns:

timezone

Since:

MMBase-1.8

fillStandardParameters

public void fillStandardParameters(Parameters p)
                            throws JspTagException

Fill standard parameters like request, response, language and locale

Parameters:

p - the parameters

Throws:

JspTagException - when parent tag is not found

Since:

MMBase-1.7.4

getCurrentBlock

protected Block getCurrentBlock()
                         throws JspTagException

Throws:

JspTagException

Since:

MMBase-1.9

setVartype

public void setVartype(String t)
                throws JspTagException

Throws:

JspTagException

setListdelimiter

public final void setListdelimiter(String l)
                            throws JspTagException

Set list delimiter

Parameters:

l - delimiter

Throws:

JspTagException - when parsing of attributes fails

Since:

MMBase-1.8

setJspvar

public void setJspvar(String j)

setWrite

public final void setWrite(String w)
                    throws JspTagException

Throws:

JspTagException

setEscape

public final void setEscape(String e)
                     throws JspTagException

Throws:

JspTagException

getWriterValue

public final Object getWriterValue()

haveBody

public final void haveBody()

getEscapedValue

protected Object getEscapedValue(Object value)
                          throws JspTagException

Returns the escaped value associated with this tag, but only if the escape attribute was set explicitly (so not when only inherited from content-tag).

Parameters:

value - initial value

Returns:

escaped value

Throws:

JspTagException - when parsing of attributes fails

Since:

MMBase-1.8

getFormTag

public FormTag getFormTag(boolean excpetion,
                          Attribute form)
                   throws JspTagException

Get the surrounding form tag

Parameters:

excpetion - throw exception when form tag not found

form - name of form

Returns:

FormTag

Throws:

JspTagException - when parsing of attributes fails

Since:

MMBase-1.8.5

getQuery

protected final Query getQuery(Attribute container)
                        throws JspTagException

Implements a getQuery for QueryContainerReferrers

Throws:

JspTagException

Since:

MMBase-1.9.0

appendMoreParameters

public String appendMoreParameters(String connector,
                                   String amp,
                                   StringBuffer buf)
                            throws JspTagException

Deprecated.

Can be overriden in extensions.

Returns:

new connector

Throws:

JspTagException

Since:

MMBase-1.8.5