abstractfieldtag.java

java 写的一个新闻发布系统

package org.jahia.taglibs.field;

import org.jahia.data.JahiaData;
import org.jahia.data.fields.*;
import org.jahia.data.containers.JahiaContainer;
import org.jahia.exceptions.JahiaException;
import org.jahia.taglibs.container.*;
import org.jahia.taglibs.util.*;
import org.jahia.utils.JahiaConsole;

import java.io.*;
import java.util.*;

import javax.servlet.*;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;


/**
 * Class AbstractFieldTag : defines common code for Jahia fields
 *
 *  This class check if the field belongs to a container, or it has been declared
 *  directly on the page
 *
 * @author  Jerome Tamiotti
 */
public abstract class AbstractFieldTag extends TagSupport {

    protected String name   =  "";
    private String title  =  "";
    private String value  =  "";
    private int pageId = -1;
    private int pageLevel = -1;
	private String declarationOnly = "false";
	
    public void setName(String name) {
        this.name = name;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public void setValue(String value) {
        this.value = value;
    }

    public void setDeclarationOnly(String value) {
        this.declarationOnly = value;
    }

    public void setPageId(String pageId) {
        try {
            this.pageId = Integer.parseInt(pageId);
        } catch (NumberFormatException nfe) {
            JahiaConsole.println("AbstractFieldTag: setPageId", "The given page id is not a number");
        }
    }

    public void setPageLevel(String pageLevel) {
        try {
            this.pageLevel = Integer.parseInt(pageLevel);
        } catch (NumberFormatException nfe) {
            JahiaConsole.println("AbstractFieldTag: setPageLevel", "The given page level is not a number");
        }
    }

    public int doStartTag() throws JspTagException {

        if (this.title.equals("")) {
            this.title = this.name;
        }

        ServletRequest request = pageContext.getRequest();
        JspWriter out = pageContext.getOut();

        JahiaData jData = (JahiaData) request.getAttribute("org.jahia.data.JahiaData");
        if (jData == null) {
            HashMap tempEngineMap = (HashMap) request.getAttribute("org.jahia.engines.EngineHashMap");
            jData                 = (JahiaData) tempEngineMap.get("jData");
        }

        try {
            // checks if the field is absolute
            if (this.pageId == -1) {
                // check for page level
                if (this.pageLevel != -1) {
                    this.pageId = jData.gui().getLevelID(this.pageLevel);
                }
            }
        } catch (JahiaException je) {
            JahiaConsole.printe("AbstractField.doStartTag:getLevelID call", je);
        }

        // checks if in declaration phase or if there are already container
        JahiaContainer container = null;
        // checks if we are inside a container
        ContainerTag parent = (ContainerTag) findAncestorWithClass(this, ContainerTag.class);
        if (parent != null) {

            ContainerListTag containerListTag = (ContainerListTag)parent.getParent();
            if (containerListTag != null) {
                if (containerListTag.isDeclarationPass()) {
                    // must be declared as a field of the enclosing container list, if not already done
                    // 28.02.2002 NK, added the check bellow to avoid multiple declaration
                    //				  of the same field in the container list structure.
                    if ( !containerListTag.isFieldAlreadyDeclared(this.name) ) {
                    
	                    containerListTag.addField(this.name);
	                    // declares the field when it is not an absolute field,
	                    // or when it is an absolute one and the current page is the home page
	                    if ( this.pageId == -1 || this.pageId == jData.page().getID() ) {
	                        try {
	                            jData.containers().declareField( this.name, this.title, getFieldType(), this.value );
	                        } catch (JahiaException je) {
	                            // this case can be valid if we are using the field multiple times...
	                            // JahiaConsole.println("AbstractField.doStartTag:declaredField call", "Field was probably already declared");
	                        }
	                    }
	                }
                    return SKIP_BODY;
                } else {
                }
            }

            container = parent.getContainer();
        }


        try {

            if (parent == null) {
                JahiaField theField = getField(jData);
                if (theField != null) {
        			if ( !declarationOnly.equals("true") )
                		out.print( readValue(jData, theField.getValue()) );
                }
            } else {
                if (parent.displayBody()) {
                    // must display the field of the current container
                    if (container != null) {
                        //out.print(container.getField(this.name).getValue());
                        if ( !declarationOnly.equals("true") )
                       		out.print( readValue( jData, container.getField(this.name).getValue() ) );
                    }
                }
            }
        } catch (IOException ioe) {
            JahiaConsole.println("AbstractFieldTag: doStartTag","Error while displaying tag '" + this.name + "' : " + ioe.toString());
        } catch (JahiaException je) {
            JahiaConsole.println("AbstractFieldTag: doStartTag","Error while displaying tag '" + this.name + "' : " + je.toString());
        } catch (NullPointerException npe) {
            JahiaConsole.println("AbstractFieldTag: doStartTag","Error while displaying tag '" + this.name + "' : " + npe.toString());
        }
        return SKIP_BODY;
    }


    private JahiaField getField(JahiaData jData) throws JahiaException {

        if ( this.pageId == -1   // the field is not absolute
             || jData.page().getID()== this.pageId ) {
             // the current page is the page that declares the absolute field
             // then we have to check if the field is already declared
             //if ( !jData.fields().checkDeclared(this.name) ) {
                // declare it now !
                jData.fields().declareField( this.name, this.title, getFieldType(), this.value );
             //}
             return jData.fields().getField(this.name);
        }
        // according to the previous tests, the only remaining case is
        // when the field is absolute and the current page is not the declaring page,
        // so return an absolute field of another page
        return jData.fields().getAbsoluteField(this.name, this.pageId);
    }


    public String readValue(JahiaData jData, String value) {
        // this method body can change according to the field type
        // for example, text fields may be truncated, so this method
        // will be overloaded in the subclass TextFieldTag
       	return value;
    }

    // method to implement in subclasses
    public abstract int getFieldType();

}