org.springframework.web.servlet.tags.form
Class SelectTag

java.lang.Object
  javax.servlet.jsp.tagext.TagSupport
      org.springframework.web.servlet.tags.RequestContextAwareTag
          org.springframework.web.servlet.tags.HtmlEscapingAwareTag
              org.springframework.web.servlet.tags.form.AbstractFormTag
                  org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag
                      org.springframework.web.servlet.tags.form.AbstractHtmlElementTag
                          org.springframework.web.servlet.tags.form.AbstractHtmlInputElementTag
                              org.springframework.web.servlet.tags.form.SelectTag

All Implemented Interfaces:

java.io.Serializable, javax.servlet.jsp.tagext.DynamicAttributes, javax.servlet.jsp.tagext.IterationTag, javax.servlet.jsp.tagext.JspTag, javax.servlet.jsp.tagext.Tag, javax.servlet.jsp.tagext.TryCatchFinally, EditorAwareTag

public class SelectTag
extends AbstractHtmlInputElementTag

Databinding-aware JSP tag that renders an HTML 'select' element.

Inner 'option' tags can be rendered using one of the approaches supported by the OptionWriter class.

Also supports the use of nested OptionTags or (typically one) nested OptionsTag.

Since:

2.0

Author:

Rob Harrop, Juergen Hoeller

See Also:

OptionTag, Serialized Form

Field Summary

private static java.lang.Object	EMPTY Marker object for items that have been specified but resolve to null.
private java.lang.String	itemLabel The name of the property mapped to the inner text of the 'option' tag.
private java.lang.Object	items The Collection, Map or array of objects used to generate the inner 'option' tags.
private java.lang.String	itemValue The name of the property mapped to the 'value' attribute of the 'option' tag.
static java.lang.String	LIST_VALUE_PAGE_ATTRIBUTE The PageContext attribute under which the bound value is exposed to inner OptionTags.
private java.lang.Object	multiple Indicates whether or not the 'select' tag allows multiple-selections.
private java.lang.String	size The value of the HTML 'size' attribute rendered on the final 'select' element.
private TagWriter	tagWriter The TagWriter instance that the output is being written.

Fields inherited from class org.springframework.web.servlet.tags.form.AbstractHtmlInputElementTag

ACCESSKEY_ATTRIBUTE, DISABLED_ATTRIBUTE, ONBLUR_ATTRIBUTE, ONCHANGE_ATTRIBUTE, ONFOCUS_ATTRIBUTE, READONLY_ATTRIBUTE

Fields inherited from class org.springframework.web.servlet.tags.form.AbstractHtmlElementTag

CLASS_ATTRIBUTE, DIR_ATTRIBUTE, LANG_ATTRIBUTE, ONCLICK_ATTRIBUTE, ONDBLCLICK_ATTRIBUTE, ONKEYDOWN_ATTRIBUTE, ONKEYPRESS_ATTRIBUTE, ONKEYUP_ATTRIBUTE, ONMOUSEDOWN_ATTRIBUTE, ONMOUSEMOVE_ATTRIBUTE, ONMOUSEOUT_ATTRIBUTE, ONMOUSEOVER_ATTRIBUTE, ONMOUSEUP_ATTRIBUTE, STYLE_ATTRIBUTE, TABINDEX_ATTRIBUTE, TITLE_ATTRIBUTE

Fields inherited from class org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag

COMMAND_NAME_VARIABLE_NAME, NESTED_PATH_VARIABLE_NAME

Fields inherited from class org.springframework.web.servlet.tags.RequestContextAwareTag

logger, REQUEST_CONTEXT_PAGE_ATTRIBUTE

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

pageContext

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

SelectTag()

Method Summary

int	doEndTag() Closes any block tag that might have been opened when using nested options.
void	doFinally() Clears the TagWriter that might have been left over when using nested options.
private boolean	forceMultiple() Returns 'true' if the bound value requires the resultant 'select' tag to be multi-select.
protected java.lang.String	getItemLabel() Get the value of the 'itemLabel' attribute.
protected java.lang.Object	getItems() Get the value of the 'items' attribute.
protected java.lang.String	getItemValue() Get the value of the 'itemValue' attribute.
protected java.lang.Object	getMultiple() Get the value of the HTML 'multiple' attribute rendered on the final 'select' element.
protected java.lang.String	getSize() Get the value of the 'size' attribute.
private boolean	isMultiple()
void	setItemLabel(java.lang.String itemLabel) Set the name of the property mapped to the label (inner text) of the 'option' tag.
void	setItems(java.lang.Object items) Set the Collection, Map or array of objects used to generate the inner 'option' tags.
void	setItemValue(java.lang.String itemValue) Set the name of the property mapped to the 'value' attribute of the 'option' tag.
void	setMultiple(java.lang.Object multiple) Set the value of the HTML 'multiple' attribute rendered on the final 'select' element.
void	setSize(java.lang.String size) Set the value of the HTML 'size' attribute rendered on the final 'select' element.
private static boolean	typeRequiresMultiple(java.lang.Class type) Returns 'true' for arrays, Collections and Maps.
private void	writeHiddenTagIfNecessary(TagWriter tagWriter) If using a multi-select, a hidden element is needed to make sure all items are correctly unselected on the server-side in response to a null post.
protected int	writeTagContent(TagWriter tagWriter) Renders the HTML 'select' tag to the supplied TagWriter.

Methods inherited from class org.springframework.web.servlet.tags.form.AbstractHtmlInputElementTag

getAccesskey, getDisabled, getOnblur, getOnchange, getOnfocus, getReadonly, isDisabled, isReadonly, setAccesskey, setDisabled, setOnblur, setOnchange, setOnfocus, setReadonly, writeOptionalAttributes

Methods inherited from class org.springframework.web.servlet.tags.form.AbstractHtmlElementTag

getCssClass, getCssErrorClass, getCssStyle, getDir, getDynamicAttributes, getLang, getOnclick, getOndblclick, getOnkeydown, getOnkeypress, getOnkeyup, getOnmousedown, getOnmousemove, getOnmouseout, getOnmouseover, getOnmouseup, getTabindex, getTitle, resolveCssClass, setCssClass, setCssErrorClass, setCssStyle, setDir, setDynamicAttribute, setLang, setOnclick, setOndblclick, setOnkeydown, setOnkeypress, setOnkeyup, setOnmousedown, setOnmousemove, setOnmouseout, setOnmouseover, setOnmouseup, setTabindex, setTitle, writeDefaultAttributes

Methods inherited from class org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag

autogenerateId, convertToDisplayString, getBindStatus, getBoundValue, getEditor, getId, getName, getNestedPath, getPath, getPropertyEditor, getPropertyPath, resolveId, setId, setPath

Methods inherited from class org.springframework.web.servlet.tags.form.AbstractFormTag

createTagWriter, doStartTagInternal, evaluate, evaluateBoolean, getDisplayString, getDisplayString, isDefaultHtmlEscape, writeOptionalAttribute

Methods inherited from class org.springframework.web.servlet.tags.HtmlEscapingAwareTag

isHtmlEscape, setHtmlEscape

Methods inherited from class org.springframework.web.servlet.tags.RequestContextAwareTag

doCatch, doStartTag, getRequestContext

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

doAfterBody, findAncestorWithClass, getParent, getValue, getValues, release, removeValue, setPageContext, setParent, setValue

Methods inherited from class java.lang.Object

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

Field Detail

LIST_VALUE_PAGE_ATTRIBUTE

public static final java.lang.String LIST_VALUE_PAGE_ATTRIBUTE

The PageContext attribute under which the bound value is exposed to inner OptionTags.

See Also:

Constant Field Values

EMPTY

private static final java.lang.Object EMPTY

Marker object for items that have been specified but resolve to null. Allows to differentiate between 'set but null' and 'not set at all'.

items

private java.lang.Object items

The Collection, Map or array of objects used to generate the inner 'option' tags.

itemValue

private java.lang.String itemValue

The name of the property mapped to the 'value' attribute of the 'option' tag.

itemLabel

private java.lang.String itemLabel

The name of the property mapped to the inner text of the 'option' tag.

size

private java.lang.String size

The value of the HTML 'size' attribute rendered on the final 'select' element.

multiple

private java.lang.Object multiple

Indicates whether or not the 'select' tag allows multiple-selections.

tagWriter

private TagWriter tagWriter

The TagWriter instance that the output is being written.

Only used in conjunction with nested OptionTags.

Constructor Detail

SelectTag

public SelectTag()

Method Detail

setItems

public void setItems(java.lang.Object items)

Set the Collection, Map or array of objects used to generate the inner 'option' tags.

Required when wishing to render 'option' tags from an array, Collection or Map.

Typically a runtime expression.

Parameters:

items - the items that comprise the options of this selection

getItems

protected java.lang.Object getItems()

Get the value of the 'items' attribute.

May be a runtime expression.

setItemValue

public void setItemValue(java.lang.String itemValue)

Set the name of the property mapped to the 'value' attribute of the 'option' tag.

Required when wishing to render 'option' tags from an array or Collection.

May be a runtime expression.

getItemValue

protected java.lang.String getItemValue()

Get the value of the 'itemValue' attribute.

May be a runtime expression.

setItemLabel

public void setItemLabel(java.lang.String itemLabel)

Set the name of the property mapped to the label (inner text) of the 'option' tag.

May be a runtime expression.

getItemLabel

protected java.lang.String getItemLabel()

Get the value of the 'itemLabel' attribute.

May be a runtime expression.

setSize

public void setSize(java.lang.String size)

Set the value of the HTML 'size' attribute rendered on the final 'select' element.

May be a runtime expression.

Parameters:

size - the desired value of the 'size' attribute

getSize

protected java.lang.String getSize()

Get the value of the 'size' attribute.

May be a runtime expression.

setMultiple

public void setMultiple(java.lang.Object multiple)

Set the value of the HTML 'multiple' attribute rendered on the final 'select' element.

May be a runtime expression.

getMultiple

protected java.lang.Object getMultiple()

Get the value of the HTML 'multiple' attribute rendered on the final 'select' element.

May be a runtime expression.

writeTagContent

protected int writeTagContent(TagWriter tagWriter)
                       throws javax.servlet.jsp.JspException

Renders the HTML 'select' tag to the supplied TagWriter.

Renders nested 'option' tags if the items property is set, otherwise exposes the bound value for the nested OptionTags.

Specified by:

writeTagContent in class AbstractFormTag

Returns:

valid tag render instruction as per Tag.doStartTag().

Throws:

javax.servlet.jsp.JspException

writeHiddenTagIfNecessary

private void writeHiddenTagIfNecessary(TagWriter tagWriter)
                                throws javax.servlet.jsp.JspException

If using a multi-select, a hidden element is needed to make sure all items are correctly unselected on the server-side in response to a null post.

Throws:

javax.servlet.jsp.JspException

isMultiple

private boolean isMultiple()
                    throws javax.servlet.jsp.JspException

Throws:

javax.servlet.jsp.JspException

forceMultiple

private boolean forceMultiple()
                       throws javax.servlet.jsp.JspException

Returns 'true' if the bound value requires the resultant 'select' tag to be multi-select.

Throws:

javax.servlet.jsp.JspException

typeRequiresMultiple

private static boolean typeRequiresMultiple(java.lang.Class type)

Returns 'true' for arrays, Collections and Maps.

doEndTag

public int doEndTag()
             throws javax.servlet.jsp.JspException

Closes any block tag that might have been opened when using nested options.

Specified by:

doEndTag in interface javax.servlet.jsp.tagext.Tag

Overrides:

doEndTag in class javax.servlet.jsp.tagext.TagSupport

Throws:

javax.servlet.jsp.JspException

doFinally

public void doFinally()

Clears the TagWriter that might have been left over when using nested options.

Specified by:

doFinally in interface javax.servlet.jsp.tagext.TryCatchFinally

Overrides:

doFinally in class AbstractDataBoundFormElementTag