org.apache.juneau.html

Class HtmlRender<T>

java.lang.Object

org.apache.juneau.html.HtmlRender<T>

Type Parameters:

T - The bean property type.

public abstract class HtmlRender<T>
extends Object

Allows custom rendering of bean property values when serialized as HTML.

Associated with bean properties using the @Html.render() annotation.

Using this class, you can alter the CSS style and HTML content of the bean property.

The following example shows two render classes that customize the appearance of the pctFull and status columns shown below:

// Our bean class public class FileSpace { private final String drive; private final long total, available; public FileSpace(String drive, long total, long available) { this.drive = drive; this.total = total; this.available = available; } @Html(link="drive/{drive}") public String getDrive() { return drive; } public long getTotal() { return total; } public long getAvailable() { return available; } @Html(render=FileSpacePctRender.class) public float getPctFull() { return ((100 * available) / total); } @Html(render=FileSpaceStatusRender.class) public FileSpaceStatus getStatus() { float pf = getPctFull(); if (pf < 80) return FileSpaceStatus.OK; if (pf < 90) return FileSpaceStatus.WARNING; return FileSpaceStatus.SEVERE; } } // Possible values for the getStatus() method public static enum FileSpaceStatus { OK, WARNING, SEVERE; } // Custom render for getPctFull() method public static class FileSpacePctRender extends HtmlRender<Float> { @Override public String getStyle(SerializerSession session, Float value) { if (value < 80) return "background-color:lightgreen;text-align:center"; if (value < 90) return "background-color:yellow;text-align:center"; return "background-color:red;text-align:center;border:;animation:color_change 0.5s infinite alternate"; } @Override public Object getContent(SerializerSession session, Float value) { if (value >= 90) return div( String.format("%.0f%%", value), style("@keyframes color_change { from { background-color: red; } to { background-color: yellow; }") ); return String.format("%.0f%%", value); } } // Custom render for getStatus() method public static class FileSpaceStatusRender extends HtmlRender<FileSpaceStatus> { @Override public String getStyle(SerializerSession session, FileSpaceStatus value) { return "text-align:center"; } @Override public Object getContent(SerializerSession session, FileSpaceStatus value) { switch (value) { case OK: return img().src(URI.create("servlet:/htdocs/ok.png")); case WARNING: return img().src(URI.create("servlet:/htdocs/warning.png")); default: return img().src(URI.create("servlet:/htdocs/severe.png")); } } }

Constructor Summary

Constructors

Constructor and Description
HtmlRender()

Method Summary

Modifier and Type	Method and Description
Object	getContent(SerializerSession session, T value) Returns the delegate value for the specified bean property value.
String	getStyle(SerializerSession session, T value) Returns the CSS style of the element containing the bean property value.

Methods inherited from class java.lang.Object

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

Constructor Detail

HtmlRender

public HtmlRender()

Method Detail

getStyle

public String getStyle(SerializerSession session,
                       T value)

Returns the CSS style of the element containing the bean property value.

Parameters:

session - The current serializer session. Can be used to retrieve properties and session-level information.

value - The bean property value.

Returns:

The CSS style string, or null if no style should be added.

getContent

public Object getContent(SerializerSession session,
                         T value)

Returns the delegate value for the specified bean property value.

The default implementation simply returns the same value. A typical use is to return an HTML element using one of the HTML5 DOM beans.

Parameters:

session - The current serializer session. Can be used to retrieve properties and session-level information.

value - The bean property value.

Returns:

The new bean property value.