org.apache.click.element
Class CssStyle

java.lang.Object
  org.apache.click.element.Element
      org.apache.click.element.ResourceElement
          org.apache.click.element.CssStyle

All Implemented Interfaces:

Serializable

public class CssStyle
extends ResourceElement

Provides a Css HEAD element for including inline Cascading Stylesheets using the <style> tag.

Example usage:

 public class MyPage extends Page {

     public List getHeadElements() {
         // We use lazy loading to ensure the CSS import is only added the
         // first time this method is called.
         if (headElements == null) {
             // Get the header entries from the super implementation
             headElements = super.getHeadElements();

             CssStyle cssStyle = new CssStyle("body { font: 12px arial; }");
             headElements.add(cssStyle);
         }
         return headElements;
     }
 } 

The cssStyle instance will render as follows:

 <style type="text/css">
 body { font: 12px arial; }
 </style> 

Below is an example showing how to render inline CSS from a Velocity template.

First we create a Velocity template (/css/style-template.css) which contains the variable $context that must be replaced at runtime with the application context path:

 .blue {
     background: #00ff00 url('$context/css/blue.png') no-repeat fixed center;
 } 

Next is the Page implementation:

 public class MyPage extends Page {

     public List getHeadElements() {
         // We use lazy loading to ensure the CSS is only added the first time
         // this method is called.
         if (headElements == null) {
             // Get the head elements from the super implementation
             headElements = super.getHeadElements();

             Context context = getContext();

             // Create a default template model to pass to the template
             Map model = ClickUtils.createTemplateModel(this, context);

             // Specify the path to CSS template
             String templatePath = "/css/style-template.css";

             // Create the inline Css for the given template path and model
             CssStyle cssStyle = new CssStyle(templatePath, model);
             headElements.add(cssStyle);
         }
         return headElements;
     }
 } 

The Css above will render as follows (assuming the context path is myApp):

 <style type="text/css">
 .blue {
     background: #00ff00 url('/myApp/css/blue.png') no-repeat fixed center;
 }
 </style> 

Character data (CDATA) support

Sometimes it is necessary to wrap inline Css in CDATA tags. Two use cases are common for doing this:

• For XML parsing: When using Ajax one often send back partial XML snippets to the browser, which is parsed as valid XML. However the XML parser will throw an error if the content contains reserved XML characters such as '&', '<' and '>'. For these situations it is recommended to wrap the style content inside CDATA tags.
• XHTML validation: if you want to validate your site using an XHTML validator e.g: http://validator.w3.org/.

To wrap the CSS Style content in CDATA tags, set setCharacterData(boolean) to true. Below is shown how the Css content would be rendered:

 <style type="text/css">
  /∗<![CDATA[∗/

  div > p {
    border: 1px solid black;
  }

  /∗]]>∗/
 </style> 

Notice the CDATA tags are commented out which ensures older browsers that don't understand the CDATA tag, will ignore it and only process the actual content.

For an overview of XHTML validation and CDATA tags please see http://javascript.about.com/library/blxhtml.htm.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.click.element.ResourceElement

IF_IE, IF_IE7, IF_LESS_THAN_IE7, IF_LESS_THAN_IE9, IF_LESS_THAN_OR_EQUAL_TO_IE7

Constructor Summary

CssStyle()
Construct a new Css style element.

CssStyle(String content)
Construct a new Css style element with the given content.

CssStyle(String template, Map<String,Object> model)
Construct a new Css style element for the given template path and template model.

Method Summary

boolean	equals(Object o)
String	getContent() Return the CssStyle content.
Map<String,Object>	getModel() Return the model of the template to render.
String	getTag() Returns the Css HTML tag: <style>.
String	getTemplate() Return the path of the template to render.
int	hashCode()
boolean	isCharacterData() Return true if the CssStyle's content should be wrapped in CDATA tags, false otherwise.
void	render(HtmlStringBuffer buffer) Render the HTML representation of the CssStyle element to the specified buffer.
protected void	renderContent(HtmlStringBuffer buffer) Render the CssStyle content to the specified buffer.
void	setCharacterData(boolean characterData) Sets whether the CssStyle's content should be wrapped in CDATA tags or not.
void	setContent(String content) Set the CssStyle content.
void	setModel(Map<String,Object> model) Set the model of the template to render.
void	setTemplate(String template) Set the path of the template to render.

Methods inherited from class org.apache.click.element.ResourceElement

getConditionalComment, getVersionIndicator, isRenderId, isUnique, setConditionalComment, setRenderId, setVersionIndicator

Methods inherited from class org.apache.click.element.Element

appendAttributes, getAttribute, getAttributes, getContext, getId, hasAttribute, hasAttributes, setAttribute, setId, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

CssStyle

public CssStyle()

Construct a new Css style element.

CssStyle

public CssStyle(String content)

Construct a new Css style element with the given content.

Parameters:

content - the Css content

CssStyle

public CssStyle(String template,
                Map<String,Object> model)

Construct a new Css style element for the given template path and template model.

When the CssStyle is rendered the template and model will be merged and the result will be rendered together with any CssStyle content.

For example:

 public class MyPage extends Page {
     public void onInit() {
         Context context = getContext();

         // Create a default template model
         Map model = ClickUtils.createTemplateModel(this, context);

         // Create CssStyle for the given template path and model
         CssStyle style = new CssStyle("/mypage-template.css", model);

         // Add style to the Page Head elements
         getHeadElements().add(style);
     }
 } 

Parameters:

template - the path of the template to render

model - the template model

Method Detail

getTag

public String getTag()

Returns the Css HTML tag: <style>.

Overrides:

getTag in class Element

Returns:

the Css HTML tag: <style>

getContent

public String getContent()

Return the CssStyle content.

Returns:

the CssStyle content

setContent

public void setContent(String content)

Set the CssStyle content.

Parameters:

content - the CssStyle content

isCharacterData

public boolean isCharacterData()

Return true if the CssStyle's content should be wrapped in CDATA tags, false otherwise.

Returns:

true if the CssStyle's content should be wrapped in CDATA tags, false otherwise

setCharacterData

public void setCharacterData(boolean characterData)

Sets whether the CssStyle's content should be wrapped in CDATA tags or not.

Parameters:

characterData - true indicates that the CssStyle's content should be wrapped in CDATA tags, false otherwise

getTemplate

public String getTemplate()

Return the path of the template to render.

Returns:

the path of the template to render

See Also:

setTemplate(java.lang.String)

setTemplate

public void setTemplate(String template)

Set the path of the template to render.

If the template property is set, the template and model will be merged and the result will be rendered together with any CssStyle content.

Parameters:

template - the path of the template to render

getModel

public Map<String,Object> getModel()

Return the model of the template to render.

Returns:

the model of the template to render

See Also:

setModel(java.util.Map)

setModel

public void setModel(Map<String,Object> model)

Set the model of the template to render.

If the template property is set, the template and model will be merged and the result will be rendered together with any CssStyle content.

Parameters:

model - the model of the template to render

render

public void render(HtmlStringBuffer buffer)

Render the HTML representation of the CssStyle element to the specified buffer.

Overrides:

render in class ResourceElement

Parameters:

buffer - the buffer to render output to

equals

public boolean equals(Object o)

Overrides:

equals in class Object

Parameters:

o - the object with which to compare this instance with

Returns:

true if the specified object is the same as this object

See Also:

Object.equals(java.lang.Object)

hashCode

public int hashCode()

Overrides:

hashCode in class Object

Returns:

a hash code value for this object

See Also:

Object.hashCode()

renderContent

protected void renderContent(HtmlStringBuffer buffer)

Render the CssStyle content to the specified buffer.

Please note: if the template property is set, this method will merge the template and model and the result will be rendered, together with the CssStyle content, to the specified buffer.

Parameters:

buffer - the buffer to append the output to