alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Tomcat example source code file (TagInfo.java)

This example Tomcat source code file (TagInfo.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Tomcat tags/keywords

body_content_jsp, body_content_scriptless, string, string, tagattributeinfo, tagattributeinfo, tagextrainfo, tagextrainfo, taginfo, taglibraryinfo, taglibraryinfo, tagvariableinfo, validationmessage, variableinfo

The Tomcat TagInfo.java source code

/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements.  See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License.  You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

 
package javax.servlet.jsp.tagext;

/**
 * Tag information for a tag in a Tag Library;
 * This class is instantiated from the Tag Library Descriptor file (TLD)
 * and is available only at translation time.
 *
 * 
*/

public class TagInfo {

    /**
     * Static constant for getBodyContent() when it is JSP.
     */

    public static final String BODY_CONTENT_JSP = "JSP";

    /**
     * Static constant for getBodyContent() when it is Tag dependent.
     */

    public static final String BODY_CONTENT_TAG_DEPENDENT = "tagdependent";


    /**
     * Static constant for getBodyContent() when it is empty.
     */

    public static final String BODY_CONTENT_EMPTY = "empty";
    
    /**
     * Static constant for getBodyContent() when it is scriptless.
     * 
     * @since 2.0
     */ 
    public static final String BODY_CONTENT_SCRIPTLESS = "scriptless";

    /**
     * Constructor for TagInfo from data in the JSP 1.1 format for TLD.
     * This class is to be instantiated only from the TagLibrary code
     * under request from some JSP code that is parsing a
     * TLD (Tag Library Descriptor).
     *
     * Note that, since TagLibibraryInfo reflects both TLD information
     * and taglib directive information, a TagInfo instance is
     * dependent on a taglib directive.  This is probably a
     * design error, which may be fixed in the future.
     *
     * @param tagName The name of this tag
     * @param tagClassName The name of the tag handler class
     * @param bodycontent Information on the body content of these tags
     * @param infoString The (optional) string information for this tag
     * @param taglib The instance of the tag library that contains us.
     * @param tagExtraInfo The instance providing extra Tag info.  May be null
     * @param attributeInfo An array of AttributeInfo data from descriptor.
     * May be null;
     *
     */
    public TagInfo(String tagName,
	    String tagClassName,
	    String bodycontent,
	    String infoString,
	    TagLibraryInfo taglib,
	    TagExtraInfo tagExtraInfo,
	    TagAttributeInfo[] attributeInfo) {
	this.tagName       = tagName;
	this.tagClassName  = tagClassName;
	this.bodyContent   = bodycontent;
	this.infoString    = infoString;
	this.tagLibrary    = taglib;
	this.tagExtraInfo  = tagExtraInfo;
	this.attributeInfo = attributeInfo;

	if (tagExtraInfo != null)
            tagExtraInfo.setTagInfo(this);
    }
			 
    /**
     * Constructor for TagInfo from data in the JSP 1.2 format for TLD.
     * This class is to be instantiated only from the TagLibrary code
     * under request from some JSP code that is parsing a
     * TLD (Tag Library Descriptor).
     *
     * Note that, since TagLibibraryInfo reflects both TLD information
     * and taglib directive information, a TagInfo instance is
     * dependent on a taglib directive.  This is probably a
     * design error, which may be fixed in the future.
     *
     * @param tagName The name of this tag
     * @param tagClassName The name of the tag handler class
     * @param bodycontent Information on the body content of these tags
     * @param infoString The (optional) string information for this tag
     * @param taglib The instance of the tag library that contains us.
     * @param tagExtraInfo The instance providing extra Tag info.  May be null
     * @param attributeInfo An array of AttributeInfo data from descriptor.
     * May be null;
     * @param displayName A short name to be displayed by tools
     * @param smallIcon Path to a small icon to be displayed by tools
     * @param largeIcon Path to a large icon to be displayed by tools
     * @param tvi An array of a TagVariableInfo (or null)
     */
    public TagInfo(String tagName,
	    String tagClassName,
	    String bodycontent,
	    String infoString,
	    TagLibraryInfo taglib,
	    TagExtraInfo tagExtraInfo,
	    TagAttributeInfo[] attributeInfo,
	    String displayName,
	    String smallIcon,
	    String largeIcon,
	    TagVariableInfo[] tvi) {
	this.tagName       = tagName;
	this.tagClassName  = tagClassName;
	this.bodyContent   = bodycontent;
	this.infoString    = infoString;
	this.tagLibrary    = taglib;
	this.tagExtraInfo  = tagExtraInfo;
	this.attributeInfo = attributeInfo;
	this.displayName = displayName;
	this.smallIcon = smallIcon;
	this.largeIcon = largeIcon;
	this.tagVariableInfo = tvi;

	if (tagExtraInfo != null)
            tagExtraInfo.setTagInfo(this);
    }
			 
    /**
     * Constructor for TagInfo from data in the JSP 2.0 format for TLD.
     * This class is to be instantiated only from the TagLibrary code
     * under request from some JSP code that is parsing a
     * TLD (Tag Library Descriptor).
     *
     * Note that, since TagLibibraryInfo reflects both TLD information
     * and taglib directive information, a TagInfo instance is
     * dependent on a taglib directive.  This is probably a
     * design error, which may be fixed in the future.
     *
     * @param tagName The name of this tag
     * @param tagClassName The name of the tag handler class
     * @param bodycontent Information on the body content of these tags
     * @param infoString The (optional) string information for this tag
     * @param taglib The instance of the tag library that contains us.
     * @param tagExtraInfo The instance providing extra Tag info.  May be null
     * @param attributeInfo An array of AttributeInfo data from descriptor.
     * May be null;
     * @param displayName A short name to be displayed by tools
     * @param smallIcon Path to a small icon to be displayed by tools
     * @param largeIcon Path to a large icon to be displayed by tools
     * @param tvi An array of a TagVariableInfo (or null)
     * @param dynamicAttributes True if supports dynamic attributes
     *
     * @since 2.0
     */
    public TagInfo(String tagName,
            String tagClassName,
            String bodycontent,
            String infoString,
            TagLibraryInfo taglib,
            TagExtraInfo tagExtraInfo,
            TagAttributeInfo[] attributeInfo,
            String displayName,
            String smallIcon,
            String largeIcon,
            TagVariableInfo[] tvi,
            boolean dynamicAttributes) {
        this.tagName       = tagName;
        this.tagClassName  = tagClassName;
        this.bodyContent   = bodycontent;
        this.infoString    = infoString;
        this.tagLibrary    = taglib;
        this.tagExtraInfo  = tagExtraInfo;
        this.attributeInfo = attributeInfo;
        this.displayName = displayName;
        this.smallIcon = smallIcon;
        this.largeIcon = largeIcon;
        this.tagVariableInfo = tvi;
        this.dynamicAttributes = dynamicAttributes;

        if (tagExtraInfo != null)
            tagExtraInfo.setTagInfo(this);
    }

    /**
     * The name of the Tag.
     *
     * @return The (short) name of the tag.
     */

    public String getTagName() {
	return tagName;
    }

    /**
     * Attribute information (in the TLD) on this tag.
     * The return is an array describing the attributes of this tag, as
     * indicated in the TLD.
     *
     * @return The array of TagAttributeInfo for this tag, or a
     *         zero-length array if the tag has no attributes.
     */

   public TagAttributeInfo[] getAttributes() {
       return attributeInfo;
   }

    /**
     * Information on the scripting objects created by this tag at runtime.
     * This is a convenience method on the associated TagExtraInfo class.
     *
     * @param data TagData describing this action.
     * @return if a TagExtraInfo object is associated with this TagInfo, the
     *     result of getTagExtraInfo().getVariableInfo( data ), otherwise
     *     null.
     */
   public VariableInfo[] getVariableInfo(TagData data) {
       VariableInfo[] result = null;
       TagExtraInfo tei = getTagExtraInfo();
       if (tei != null) {
	   result = tei.getVariableInfo( data );
       }
       return result;
   }

    /**
     * Translation-time validation of the attributes. 
     * This is a convenience method on the associated TagExtraInfo class.
     *
     * @param data The translation-time TagData instance.
     * @return Whether the data is valid.
     */
    public boolean isValid(TagData data) {
        TagExtraInfo tei = getTagExtraInfo();
        if (tei == null) {
	    return true;
        }
        return tei.isValid(data);
    }

    /**
     * Translation-time validation of the attributes.
     * This is a convenience method on the associated TagExtraInfo class.
     *
     * @param data The translation-time TagData instance.
     * @return A null object, or zero length array if no errors, an
     *     array of ValidationMessages otherwise.
     * @since 2.0
     */
    public ValidationMessage[] validate( TagData data ) {
	TagExtraInfo tei = getTagExtraInfo();
	if( tei == null ) {
	    return null;
	}
	return tei.validate( data );
    }

    /**
     * Set the instance for extra tag information.
     * 
     * @param tei the TagExtraInfo instance
     */
    public void setTagExtraInfo(TagExtraInfo tei) {
	tagExtraInfo = tei;
    }


    /**
     * The instance (if any) for extra tag information.
     * 
     * @return The TagExtraInfo instance, if any.
     */
    public TagExtraInfo getTagExtraInfo() {
	return tagExtraInfo;
    }


    /**
     * Name of the class that provides the handler for this tag.
     *
     * @return The name of the tag handler class.
     */
    
    public String getTagClassName() {
	return tagClassName;
    }


    /**
     * The bodycontent information for this tag.
     * If the bodycontent is not defined for this
     * tag, the default of JSP will be returned.
     *
     * @return the body content string.
     */

    public String getBodyContent() {
	return bodyContent;
    }


    /**
     * The information string for the tag.
     *
     * @return the info string, or null if 
     *         not defined
     */

    public String getInfoString() {
	return infoString;
    }


    /**
     * Set the TagLibraryInfo property.
     *
     * Note that a TagLibraryInfo element is dependent
     * not just on the TLD information but also on the
     * specific taglib instance used.  This means that
     * a fair amount of work needs to be done to construct
     * and initialize TagLib objects.
     *
     * If used carefully, this setter can be used to avoid having to
     * create new TagInfo elements for each taglib directive.
     *
     * @param tl the TagLibraryInfo to assign
     */

    public void setTagLibrary(TagLibraryInfo tl) {
	tagLibrary = tl;
    }

    /**
     * The instance of TabLibraryInfo we belong to.
     *
     * @return the tag library instance we belong to
     */

    public TagLibraryInfo getTagLibrary() {
	return tagLibrary;
    }


    // ============== JSP 2.0 TLD Information ========


    /**
     * Get the displayName.
     *
     * @return A short name to be displayed by tools,
     *         or null if not defined
     */

    public String getDisplayName() {
	return displayName;
    }

    /**
     * Get the path to the small icon.
     *
     * @return Path to a small icon to be displayed by tools,
     *         or null if not defined
     */

    public String getSmallIcon() {
	return smallIcon;
    }

    /**
     * Get the path to the large icon.
     *
     * @return Path to a large icon to be displayed by tools,
     *         or null if not defined
     */

    public String getLargeIcon() {
	return largeIcon;
    }

    /**
     * Get TagVariableInfo objects associated with this TagInfo.
     *
     * @return Array of TagVariableInfo objects corresponding to
     *         variables declared by this tag, or a zero length
     *         array if no variables have been declared
     */

    public TagVariableInfo[] getTagVariableInfos() {
	return tagVariableInfo;
    }


    // ============== JSP 2.0 TLD Information ========

    /**
     * Get dynamicAttributes associated with this TagInfo.
     *
     * @return True if tag handler supports dynamic attributes
     * @since 2.0
     */
    public boolean hasDynamicAttributes() {
        return dynamicAttributes;
    }

    /*
     * private fields for 1.1 info
     */
    private String             tagName; // the name of the tag
    private String             tagClassName;
    private String             bodyContent;
    private String             infoString;
    private TagLibraryInfo     tagLibrary;
    private TagExtraInfo       tagExtraInfo; // instance of TagExtraInfo
    private TagAttributeInfo[] attributeInfo;

    /*
     * private fields for 1.2 info
     */
    private String             displayName;
    private String             smallIcon;
    private String             largeIcon;
    private TagVariableInfo[]  tagVariableInfo;

    /*
     * Additional private fields for 2.0 info
     */
    private boolean dynamicAttributes;
}

Other Tomcat examples (source code examples)

Here is a short list of links related to this Tomcat TagInfo.java source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.