zkoss/zk

/* HtmlNativeComponent.java

    Purpose:
        
    Description:
        
    History:
        Thu Jul 19 18:05:01     2007, Created by tomyeh

Copyright (C) 2007 Potix Corporation. All Rights Reserved.

{{IS_RIGHT
    This program is distributed under LGPL Version 2.1 in the hope that
    it will be useful, but WITHOUT ANY WARRANTY.
}}IS_RIGHT
*/
package org.zkoss.zk.ui;

import java.io.StringWriter;
import java.io.Writer;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

import org.zkoss.html.HTMLs;
import org.zkoss.idom.Namespace;
import org.zkoss.lang.Strings;
import org.zkoss.zk.ui.ext.DynamicTag;
import org.zkoss.zk.ui.ext.Native;
import org.zkoss.zk.ui.ext.render.DirectContent;
import org.zkoss.zk.ui.ext.render.PrologAllowed;
import org.zkoss.zk.ui.impl.NativeHelpers;
import org.zkoss.zk.ui.sys.ComponentCtrl;
import org.zkoss.zk.ui.sys.ComponentsCtrl;
import org.zkoss.zk.ui.sys.ExecutionsCtrl;
import org.zkoss.zk.ui.sys.HtmlPageRenders;
import org.zkoss.zk.ui.sys.PropertyAccess;
import org.zkoss.zk.ui.sys.StringPropertyAccess;

/**
 * A component used to represent XML elements that are associated
 * with the native namespace (http://www.zkoss.org/2005/zk/native).
 *
 * <p>It contains the content that shall be sent directly to client.
 * It has three parts: prolog, children and epilog.
 * The prolog ({@link #getPrologContent}) and epilog ({@link #getEpilogContent})
 * are both {@link String}.
 *
 * <p>When this component is rendered ({@link #redraw}), it generates
 * the prolog first, the children and then the epilog.
 *
 * @author tomyeh
 * @since 3.0.0
 */
public class HtmlNativeComponent extends AbstractComponent implements DynamicTag, Native { //cannot be RawId since two native might have the same ID
    private static final Helper _helper = new HtmlHelper();
    private static final String ATTR_RENDER_CONTEXT = "org.zkoss.zk.native.renderContext";

    //---------
    //structure: _prefix <_tag> _prolog children _epilog </_tag> _postifx
    //---------

    private String _tag;
    private String _prolog = "", _epilog = "";
    /** The text before the tag name. */
    private String _prefix, _postfix;
    private Map<String, Object> _props;
    /** Declared namespaces ({@link Namespace}). */
    private List<Namespace> _dns;

    /** Constructs a {@link HtmlNativeComponent} component.
     * 
     */
    public HtmlNativeComponent() {
    }

    /** Constructs a {@link HtmlNativeComponent} component with the specified tag name.
     *
     * @param tag the tag name. If null or empty, plain text is assumed.
     */
    public HtmlNativeComponent(String tag) {
        setTag(tag);
    }

    /** Constructs a {@link HtmlNativeComponent} component with the specified
     * prolog and epilog.
     * @param tag the tag name. If null or empty, plain text is assumed.
     * @param prolog the content right before the children, if any.
     * @param epilog the content right after the children, if any.
     */
    public HtmlNativeComponent(String tag, String prolog, String epilog) {
        this(tag);

        _prolog = prolog != null ? prolog : "";
        _epilog = epilog != null ? epilog : "";
    }

    /** Returns the widget class, "zk.Native".
     * @since 5.0.0
     */
    public String getWidgetClass() {
        return "zk.Native";
    }

    /** Returns the tag name, or null if plain text.
     */
    public String getTag() {
        return _tag;
    }

    //Native//
    public List<Namespace> getDeclaredNamespaces() {
        if (_dns != null)
            return _dns;
        return Collections.emptyList();
    }

    public void addDeclaredNamespace(Namespace ns) {
        if (ns == null)
            throw new IllegalArgumentException();

        if (_dns == null)
            _dns = new LinkedList<Namespace>();
        _dns.add(ns);
    }

    public String getPrologContent() {
        return _prolog;
    }

    public void setPrologContent(String prolog) {
        _prolog = prolog != null ? prolog : "";
    }

    public String getEpilogContent() {
        return _epilog;
    }

    public void setEpilogContent(String epilog) {
        _epilog = epilog != null ? epilog : "";
    }

    public Helper getHelper() {
        return _helper;
    }

    //-- Component --//

    public boolean setVisible(boolean visible) {
        throw new UnsupportedOperationException("Use client-dependent attribute, such as display:none");
    }

    public void redraw(Writer out) throws java.io.IOException {
        //Note: _tag == null can NOT be handled specially
        final Execution exec = Executions.getCurrent();
        final boolean root = getParent() == null && (getPage().isComplete()
                || (exec != null && "complete".equals(ExecutionsCtrl.getPageRedrawControl(exec))));
        if (exec == null || exec.isAsyncUpdate(null) || (!root && !HtmlPageRenders.isDirectContent(exec))) {
            super.redraw(out); //renderProperties (assume in zscript)
            return;
        }

        Writer oldout = null;
        if (exec != null && !HtmlPageRenders.isZkTagsGenerated(exec) && exec.getAttribute(ATTR_TOP_NATIVE) == null) { //need to check topmost native only
            String tn;
            if (root || "html".equals(tn = _tag != null ? _tag.toLowerCase(java.util.Locale.ENGLISH) : "")
                    || "body".equals(tn) || "head".equals(tn)) {
                exec.setAttribute(ATTR_TOP_NATIVE, Boolean.TRUE);
                oldout = out;
                out = new StringWriter();
            }
        }

        out.write(getPrologHalf());

        //children
        Component child = getFirstChild();
        if (child == null) {
            //need to invoke outStandalone to generate response if any (Bug 3009925)
            //however, it is not required if not root (since others will invoke)
            if (root)
                HtmlPageRenders.outStandalone(exec, null, out);
        } else {
            if (root)
                HtmlPageRenders.setDirectContent(exec, true);
            do {
                Component next = child.getNextSibling();
                if (child instanceof Native || ((ComponentCtrl) child).getExtraCtrl() instanceof DirectContent) {
                    ((ComponentCtrl) child).redraw(out);
                } else {
                    HtmlPageRenders.setDirectContent(exec, false);
                    HtmlPageRenders.outStandalone(exec, child, out);
                    HtmlPageRenders.setDirectContent(exec, true);
                }
                child = next;
            } while (child != null);
        }

        out.write(getEpilogHalf());

        if (oldout != null) {
            exec.removeAttribute(ATTR_TOP_NATIVE);

            //order: <html><head><zkhead><body>
            //1. replace <zkhead/> if found
            //2. insert before </head> if found
            //3. insert after <body> if found
            //4. insert after <html> if found
            //5. insert at the end if none of above found
            final StringBuffer sb = ((StringWriter) out).getBuffer();
            if (!HtmlPageRenders.isZkTagsGenerated(exec)) {
                int jhead = -1, //anchor of header
                        junav = -1, //anchor of unavailable
                        head = -1, //index of <head>
                        heade = -1, //index of </head>
                        html = -1; //index of <html>
                for (int j = 0, len = sb.length(); (j = sb.indexOf("<", j)) >= 0;) {
                    ++j;
                    if (jhead < 0 && startsWith(sb, "zkhead", j)) {
                        int l = Strings.indexOf(sb, '>', j) + 1;
                        sb.delete(jhead = --j, l); //jhead found
                        len = sb.length();
                    } else if (head < 0 && startsWith(sb, "head", j)) {
                        head = Strings.indexOf(sb, '>', j) + 1;
                    } else if (html < 0 && startsWith(sb, "html", j)) {
                        html = Strings.indexOf(sb, '>', j) + 1;
                    } else if (junav < 0 && startsWith(sb, "body", j)) {
                        junav = Strings.indexOf(sb, '>', j) + 1; //junav found
                        break; //done
                    } else if (sb.charAt(j) == '/' && startsWith(sb, "head", ++j)) {
                        heade = j - 2;
                    }
                }

                boolean disableUnavailable = false;
                if (jhead < 0 && ((jhead = head) < 0) //use <head> if no <zkhead>
                        && ((jhead = heade) < 0) //use </head> if no <head> (though unlikely)
                        && ((jhead = junav) < 0) //use <body> if no </head>
                        && ((jhead = html) < 0)) { //use <html> if no <body>
                    if (_tag != null) {
                        final String tn = _tag.toLowerCase(java.util.Locale.ENGLISH);
                        if ("div".equals(tn) || "span".equals(tn)) {
                            l_loop: for (int j = 0, len = sb.length(); j < len; ++j)
                                switch (sb.charAt(j)) {
                                case '>':
                                    disableUnavailable = true; //make output cleaner
                                    jhead = j + 1; //found
                                case '=': //it might have something depends on JS
                                case '"':
                                    break l_loop;
                                }
                        }
                    }
                    if (jhead < 0)
                        jhead = 0; //insert at head if not found
                }

                final String msg = HtmlPageRenders.outUnavailable(exec);
                //called if disableUnavailable (so it won't be generated later)
                if (msg != null && !disableUnavailable) {
                    if (junav < 0) {
                        if (html >= 0)
                            junav = sb.lastIndexOf("</html");
                    }
                    if (junav >= 0)
                        sb.insert(junav < jhead ? jhead : junav, msg);
                    else
                        sb.append(msg);
                }

                final String zktags = HtmlPageRenders.outHeaderZkTags(exec, getPage());
                if (zktags != null)
                    sb.insert(jhead, zktags);
            }

            oldout.write(sb.toString());
        }
    }

    /** Used to indicate the redrawing of the top native is found. */
    private static final String ATTR_TOP_NATIVE = "zkHtmlTopNative";

    private static boolean startsWith(StringBuffer sb, String tag, int start) {
        int end = start + tag.length();
        char cc;
        return sb.length() > end && tag.equalsIgnoreCase(sb.substring(start, end))
                && ((cc = sb.charAt(end)) < 'a' || cc > 'z') && (cc < 'A' || cc > 'Z');
    }

    protected void renderProperties(org.zkoss.zk.ui.sys.ContentRenderer renderer) throws java.io.IOException {
        super.renderProperties(renderer);

        render(renderer, "prolog", getPrologHalf());
        render(renderer, "epilog", getEpilogHalf());
    }

    private String getPrologHalf() {
        final StringBuffer sb = new StringBuffer(128);
        final Helper helper = getHelper();
        //don't use _helper directly, since the derive might override it

        if (_prefix != null)
            sb.append(_prefix);

        //first half
        helper.getFirstHalf(sb, _tag, _props, _dns);

        //prolog
        sb.append(_prolog); //no encoding
        return sb.toString();
    }

    private String getEpilogHalf() {
        final StringBuffer sb = new StringBuffer(128);
        final Helper helper = getHelper();

        //epilog
        sb.append(_epilog);

        //second half
        helper.getSecondHalf(sb, _tag);

        if (_postfix != null)
            sb.append(_postfix);
        return sb.toString();
    }

    //DynamicTag//
    /** Sets the tag name.
     *
     * @param tag the tag name. If null or empty, plain text is assumed.
     */
    public void setTag(String tag) throws WrongValueException {
        _tag = tag != null && tag.length() > 0 ? tag : null;
    }

    public boolean hasTag(String tag) {
        return true; //accept anything
    }

    public boolean hasDynamicProperty(String name) {
        return ComponentsCtrl.isReservedAttribute(name);
    }

    public Object getDynamicProperty(String name) {
        return _props != null ? _props.get(name) : null;
    }

    public Map<String, Object> getDynamicProperties() {
        return _props;
    }

    public void setDynamicProperty(String name, Object value) throws WrongValueException {
        if (name == null)
            throw new WrongValueException("name required");

        if (value == null) {
            if (_props != null)
                _props.remove(name);
        } else {
            if (_props == null)
                _props = new LinkedHashMap<String, Object>();
            if ("sclass".equals(name))
                _props.put("class", value);
            else
                _props.put(name, value);
        }
    }

    /** The HTML helper.
     */
    public static class HtmlHelper implements Helper {
        public Component newNative(String text) {
            final HtmlNativeComponent nc = new HtmlNativeComponent();
            if (text != null)
                nc.setPrologContent(text);
            return nc;
        }

        public void getFirstHalf(StringBuffer sb, String tag, Map<String, Object> props,
                Collection<Namespace> namespaces) {
            if (tag != null)
                sb.append('<').append(tag);

            NativeHelpers.getAttributes(sb, props, namespaces);

            if (tag != null) {
                final String tn = tag.toLowerCase(java.util.Locale.ENGLISH);
                if ("zkhead".equals(tn) || HTMLs.isOrphanTag(tn))
                    sb.append('/');
                sb.append('>');
            }
        }

        public void getSecondHalf(StringBuffer sb, String tag) {
            if (tag != null) {
                final String tn = tag.toLowerCase(java.util.Locale.ENGLISH);
                if ("zkhead".equals(tn) || HTMLs.isOrphanTag(tn))
                    return;

                sb.append("</").append(tag).append('>');
            }
        }

        public void appendText(StringBuffer sb, String text) {
            sb.append(text); //don't encode (bug 2689443)
        }
    }

    //--ComponentCtrl--//
    private static HashMap<String, PropertyAccess> _properties = new HashMap<String, PropertyAccess>(5);

    static {
        _properties.put("id", new StringPropertyAccess() {
            public void setValue(Component cmp, String value) {
                ((HtmlNativeComponent) cmp).setId(value);
            }

            public String getValue(Component cmp) {
                return ((HtmlNativeComponent) cmp).getId();
            }
        });

        _properties.put("tag", new StringPropertyAccess() {
            public void setValue(Component cmp, String value) {
                ((HtmlNativeComponent) cmp).setTag(value);
            }

            public String getValue(Component cmp) {
                return ((HtmlNativeComponent) cmp).getTag();
            }
        });

        _properties.put("epilogContent", new StringPropertyAccess() {
            public void setValue(Component cmp, String value) {
                ((HtmlNativeComponent) cmp).setEpilogContent(value);
            }

            public String getValue(Component cmp) {
                return ((HtmlNativeComponent) cmp).getEpilogContent();
            }
        });
        _properties.put("prologContent", new StringPropertyAccess() {
            public void setValue(Component cmp, String value) {
                ((HtmlNativeComponent) cmp).setPrologContent(value);
            }

            public String getValue(Component cmp) {
                return ((HtmlNativeComponent) cmp).getPrologContent();
            }
        });
    }

    public PropertyAccess getPropertyAccess(String prop) {
        PropertyAccess pa = _properties.get(prop);
        if (pa != null)
            return pa;
        return super.getPropertyAccess(prop);
    }

    public Object getExtraCtrl() {
        return new ExtraCtrl();
    }

    protected class ExtraCtrl implements DirectContent, PrologAllowed {
        //-- PrologAware --//
        public void setPrologContent(String prolog) {
            _prefix = prolog;
            //Notice: it is used as prefix (shown before the tag and children)
            //while _prolog is the text shown after the tag and before the children
        }
    }
}