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

java.lang.Object
  org.springframework.web.servlet.tags.form.OptionWriter

Direct Known Subclasses:

OptionsTag.OptionsWriter

 class OptionWriter
extends java.lang.Object

Provides supporting functionality to render a list of 'option' tags based on some source object. This object can be either an array, a Collection, or a Map.

Using an array or a Collection:

If you supply an array or Collection source object to render the inner 'option' tags, you may optionally specify the name of the property on the objects which corresponds to the value of the rendered 'option' (i.e., the valueProperty) and the name of the property that corresponds to the label (i.e., the labelProperty). These properties are then used when rendering each element of the array/Collection as an 'option'. If either property name is omitted, the value of Object.toString() of the corresponding array/Collection element is used instead. However, if the item is an enum, Enum.name() is used as the default value.

Using a Map:

You can alternatively choose to render 'option' tags by supplying a Map as the source object.

If you omit property names for the value and label:

• the key of each Map entry will correspond to the value of the rendered 'option', and
• the value of each Map entry will correspond to the label of the rendered 'option'.

If you supply property names for the value and label:

• the value of the rendered 'option' will be retrieved from the valueProperty on the object corresponding to the key of each Map entry, and
• the label of the rendered 'option' will be retrieved from the labelProperty on the object corresponding to the value of each Map entry.

When using either of these approaches:

• Property names for the value and label are specified as arguments to the constructor.
• An 'option' is marked as 'selected' if its key matches the value that is bound to the tag instance.

Since:

2.0

Author:

Rob Harrop, Juergen Hoeller, Sam Brannen, Scott Andrews

Field Summary

private BindStatus	bindStatus
private boolean	htmlEscape
private java.lang.String	labelProperty
private java.lang.Object	optionSource
private java.lang.String	valueProperty

Constructor Summary

OptionWriter(java.lang.Object optionSource, BindStatus bindStatus, java.lang.String valueProperty, java.lang.String labelProperty, boolean htmlEscape)
Creates a new OptionWriter for the supplied objectSource.

Method Summary

private void	doRenderFromCollection(java.util.Collection optionCollection, TagWriter tagWriter) Renders the inner 'option' tags using the supplied Collection of objects as the source.
private java.lang.String	getDisplayString(java.lang.Object value) Determines the display value of the supplied Object, HTML-escaped as required.
protected boolean	isOptionDisabled() Determine whether the option fields should be disabled.
private boolean	isOptionSelected(java.lang.Object resolvedValue) Determine whether the supplied values matched the selected value.
protected java.lang.String	processOptionValue(java.lang.String resolvedValue) Process the option value before it is written.
private void	renderFromArray(TagWriter tagWriter) Renders the inner 'option' tags using the optionSource.
private void	renderFromCollection(TagWriter tagWriter) Renders the inner 'option' tags using the optionSource.
private void	renderFromEnum(TagWriter tagWriter) Renders the inner 'option' tags using the optionSource.
private void	renderFromMap(TagWriter tagWriter) Renders the inner 'option' tags using the supplied Map as the source.
private void	renderOption(TagWriter tagWriter, java.lang.Object item, java.lang.Object value, java.lang.Object label) Renders an HTML 'option' with the supplied value and label.
protected void	writeCommonAttributes(TagWriter tagWriter) Writes default attributes configured to the supplied TagWriter.
void	writeOptions(TagWriter tagWriter) Write the 'option' tags for the configured optionSource to the supplied TagWriter.

Methods inherited from class java.lang.Object

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

Field Detail

optionSource

private final java.lang.Object optionSource

bindStatus

private final BindStatus bindStatus

valueProperty

private final java.lang.String valueProperty

labelProperty

private final java.lang.String labelProperty

htmlEscape

private final boolean htmlEscape

Constructor Detail

OptionWriter

public OptionWriter(java.lang.Object optionSource,
                    BindStatus bindStatus,
                    java.lang.String valueProperty,
                    java.lang.String labelProperty,
                    boolean htmlEscape)

Creates a new OptionWriter for the supplied objectSource.

Parameters:

optionSource - the source of the options (never null)

bindStatus - the BindStatus for the bound value (never null)

valueProperty - the name of the property used to render option values (optional)

labelProperty - the name of the property used to render option labels (optional)

Method Detail

writeOptions

public void writeOptions(TagWriter tagWriter)
                  throws JspException

Write the 'option' tags for the configured optionSource to the supplied TagWriter.

Throws:

JspException

renderFromArray

private void renderFromArray(TagWriter tagWriter)
                      throws JspException

Renders the inner 'option' tags using the optionSource.

Throws:

JspException

See Also:

doRenderFromCollection(java.util.Collection, TagWriter)

renderFromMap

private void renderFromMap(TagWriter tagWriter)
                    throws JspException

Renders the inner 'option' tags using the supplied Map as the source.

Throws:

JspException

See Also:

renderOption(TagWriter, Object, Object, Object)

renderFromCollection

private void renderFromCollection(TagWriter tagWriter)
                           throws JspException

Renders the inner 'option' tags using the optionSource.

Throws:

JspException

See Also:

doRenderFromCollection(java.util.Collection, TagWriter)

renderFromEnum

private void renderFromEnum(TagWriter tagWriter)
                     throws JspException

Renders the inner 'option' tags using the optionSource.

Throws:

JspException

See Also:

doRenderFromCollection(java.util.Collection, TagWriter)

doRenderFromCollection

private void doRenderFromCollection(java.util.Collection optionCollection,
                                    TagWriter tagWriter)
                             throws JspException

Renders the inner 'option' tags using the supplied Collection of objects as the source. The value of the valueProperty field is used when rendering the 'value' of the 'option' and the value of the labelProperty property is used when rendering the label.

Throws:

JspException

renderOption

private void renderOption(TagWriter tagWriter,
                          java.lang.Object item,
                          java.lang.Object value,
                          java.lang.Object label)
                   throws JspException

Renders an HTML 'option' with the supplied value and label. Marks the value as 'selected' if either the item itself or its value match the bound value.

Throws:

JspException

getDisplayString

private java.lang.String getDisplayString(java.lang.Object value)

Determines the display value of the supplied Object, HTML-escaped as required.

processOptionValue

protected java.lang.String processOptionValue(java.lang.String resolvedValue)

Process the option value before it is written. The default implementation simply returns the same value unchanged.

isOptionSelected

private boolean isOptionSelected(java.lang.Object resolvedValue)

Determine whether the supplied values matched the selected value. Delegates to SelectedValueComparator.isSelected(org.springframework.web.servlet.support.BindStatus, java.lang.Object).

isOptionDisabled

protected boolean isOptionDisabled()
                            throws JspException

Determine whether the option fields should be disabled.

Throws:

JspException

writeCommonAttributes

protected void writeCommonAttributes(TagWriter tagWriter)
                              throws JspException

Writes default attributes configured to the supplied TagWriter.

Throws:

JspException