atg.taglib.json
Class JsonBaseTag

java.lang.Object
  javax.servlet.jsp.tagext.SimpleTagSupport
      atg.taglib.json.JsonBaseTag

All Implemented Interfaces:

javax.servlet.jsp.tagext.JspTag, javax.servlet.jsp.tagext.SimpleTag

Direct Known Subclasses:

JsonArrayTag, JsonObjectTag, JsonPropertyTag

public abstract class JsonBaseTag
extends javax.servlet.jsp.tagext.SimpleTagSupport

Abstract base class for all JSON tags

Version:

$Id$

Author:

James Wiltshire

Field Summary

protected java.lang.Boolean	mEscapeXmlOriginalValue
protected boolean	mEscapeXmlValueSet
protected java.lang.String	mName
protected boolean	mNewStackCreated
protected boolean	mTrim
protected static int	PRETTY_PRINT_INDENT

Constructor Summary

JsonBaseTag()

Method Summary

protected java.util.Stack	createEntityStack() Create a new entity stack and set it in pageContext
protected boolean	entityStackExists() Does an entity stack exist?
protected JsonEntity	getCurrentEntity() Get the topmost JSONObject or JSONArray from the stack
protected java.lang.Object	getDefaultValue(java.lang.String pParamKey, java.lang.Object pDefaultConstant) Get the default value for a parameter.
protected java.util.Stack	getEntityStack() Get the JSON object stack.
boolean	getEscapeXml() Gets the value of the EscapeXml flag.
java.lang.Boolean	getEscapeXmlDefault() Get the default value of the escapeXml property
java.lang.String	getName() Gets the Name
int	getPrettyPrintIndentFactor() Get the number of spaces that should be used to indent the pretty-printed output, or 0 if no pretty-printing should be used
boolean	getTrim() Gets the Trim
protected boolean	isRootTag() Is this tag the root json: tag?
protected void	processTagEnd(JsonEntity pNewEntity) Process the end of a tag.
protected void	removeEntityStack() Remove the entity stack object from page context
protected void	resetEscapeXmlValue() Replace the escapeXml value with the original value if this tag modified it
void	setEscapeXml(boolean pEscapeXml) Sets the EscapeXml flag.
void	setName(java.lang.String pName) Sets the Name
void	setPrettyPrint(boolean pPrettyPrint) Sets the PrettyPrint flag.
void	setTrim(boolean pTrim) Sets the Trim
protected java.lang.Object	trimAndEscapeValue(java.lang.Object pValue) Trim and EscapeXml chars in the value depending on whether the trim and escapeXml attributes have been set

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

doTag, findAncestorWithClass, getJspBody, getJspContext, getParent, setJspBody, setJspContext, setParent

Methods inherited from class java.lang.Object

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

Field Detail

PRETTY_PRINT_INDENT

protected static final int PRETTY_PRINT_INDENT

See Also:

Constant Field Values

mName

protected java.lang.String mName

mTrim

protected boolean mTrim

mNewStackCreated

protected boolean mNewStackCreated

mEscapeXmlOriginalValue

protected java.lang.Boolean mEscapeXmlOriginalValue

mEscapeXmlValueSet

protected boolean mEscapeXmlValueSet

Constructor Detail

JsonBaseTag

public JsonBaseTag()

Method Detail

getName

public java.lang.String getName()

Gets the Name

Returns:

the Name

setName

public void setName(java.lang.String pName)

Sets the Name

Parameters:

pName - The Name to set

getTrim

public boolean getTrim()

Gets the Trim

Returns:

the Trim

setTrim

public void setTrim(boolean pTrim)

Sets the Trim

Parameters:

pTrim - The Trim to set

setPrettyPrint

public void setPrettyPrint(boolean pPrettyPrint)

Sets the PrettyPrint flag. If set, then any JSON output should be nicely formatted

Parameters:

pPrettyPrint - The PrettyPrint to set

getPrettyPrintIndentFactor

public int getPrettyPrintIndentFactor()

Get the number of spaces that should be used to indent the pretty-printed output, or 0 if no pretty-printing should be used

Returns:

The number of spaces to indent when pretty printing

getEscapeXml

public boolean getEscapeXml()

Gets the value of the EscapeXml flag. This can be set on any tag by setting the escapeXml attribute to true, or it can be set by setting a page attribute atg.taglib.json.escapeXml. When set on a tag it will recursively apply to all sub-tags, but may be overriden by any sub-tag.
Defaults to true

Returns:

the EscapeXml flag value

setEscapeXml

public void setEscapeXml(boolean pEscapeXml)

Sets the EscapeXml flag. If set, then any output will be xml-escaped

Parameters:

pEscapeXml - The EscapeXml to set

getEscapeXmlDefault

public java.lang.Boolean getEscapeXmlDefault()

Get the default value of the escapeXml property

Returns:

the default escapeXml value

resetEscapeXmlValue

protected void resetEscapeXmlValue()

Replace the escapeXml value with the original value if this tag modified it

getEntityStack

protected java.util.Stack getEntityStack()
                                  throws javax.servlet.jsp.JspException

Get the JSON object stack. This is stored as an attribute in the page context. Request scope is used so that jsp:include can be used to nest json: tags in included pages.

If an entity stack does not exists, then this method will create a new one

Returns:

The JSON Entity Stack

Throws:

javax.servlet.jsp.JspException - If there is a problem creating a new entity stack

createEntityStack

protected java.util.Stack createEntityStack()
                                     throws javax.servlet.jsp.JspException

Create a new entity stack and set it in pageContext

Returns:

The newly created JSON entity statck

Throws:

javax.servlet.jsp.JspException

removeEntityStack

protected void removeEntityStack()

Remove the entity stack object from page context

getCurrentEntity

protected JsonEntity getCurrentEntity()
                               throws javax.servlet.jsp.JspException

Get the topmost JSONObject or JSONArray from the stack

Returns:

the topmost JsonEntity on the stack

Throws:

javax.servlet.jsp.JspException - if unable to get the object stack

entityStackExists

protected boolean entityStackExists()

Does an entity stack exist?

Returns:

true if an entity stack is found in pageContext, false otherwise

isRootTag

protected boolean isRootTag()

Is this tag the root json: tag?

Returns:

true if this tag instance is the root tag, false otherwise

getDefaultValue

protected java.lang.Object getDefaultValue(java.lang.String pParamKey,
                                           java.lang.Object pDefaultConstant)

Get the default value for a parameter. This will search each of the following locations in order, returning the first value that it finds.

1. page/request/session/application attributes. Uses findAttribute to try and find the attribute
2. Servlet Context initParams - as set in a web.xml context-param
3. The Default Constant value passed in to this method

Parameters:

pParamKey - The key of the param.

Returns:

trimAndEscapeValue

protected java.lang.Object trimAndEscapeValue(java.lang.Object pValue)

Trim and EscapeXml chars in the value depending on whether the trim and escapeXml attributes have been set

Parameters:

pValue - The value to trim and xml-escape

Returns:

The processed value

processTagEnd

protected void processTagEnd(JsonEntity pNewEntity)
                      throws javax.servlet.jsp.JspException,
                             JSONException

Process the end of a tag. Check to see if this is the top level tag that created the entity stack, and if so, render the JSON data to the output stream.

Parameters:

pNewEntity - The entity that has just been created by this tag

Throws:

javax.servlet.jsp.JspException

JSONException