javax.faces.context.PartialResponseWriter Maven / Gradle / Ivy

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package javax.faces.context;

import java.io.IOException;
import java.util.Map;
import javax.faces.render.ResponseStateManager;

/**
 * PartialResponseWriter
 * decorates an existing ResponseWriter to support the
 * generation of a partial response suitable for Ajax operations.
 * In addition to the markup generation methods inherited from
 * javax.faces.context.ResponseWriter, this class provides
 * methods for constructing the standard partial response elements.
 *
 * @since 2.0
 */
public class PartialResponseWriter extends ResponseWriterWrapper {
    // True when we need to close a changes tag
    //
    private boolean inChanges = false;

    // True when we need to close a before insert tag
    //
    private boolean inInsertBefore = false;

    // True when we need to close afer insert tag
    //
    private boolean inInsertAfter = false;
    
    // True when we need to close an update tag
    //
    private boolean inUpdate = false;

    ResponseWriter writer;

    /**
     * Reserved ID value to indicate
     * entire ViewRoot.
     *
     * @since 2.0
     */
    public static final String RENDER_ALL_MARKER = "javax.faces.ViewRoot";

    /**
     * Reserved ID value to indicate
     * serialized ViewState.
     *
     * @since 2.0
     */
    public static final String VIEW_STATE_MARKER = ResponseStateManager.VIEW_STATE_PARAM;

    /**
     * Create a PartialResponseWriter.
     *
     * @param writer The writer to wrap.
     * @since 2.0
     */
    public PartialResponseWriter(ResponseWriter writer) {
        this.writer = writer;
    }

    /**
     * Return the wrapped
     * {@link ResponseWriter} instance.
     *
     * @see ResponseWriterWrapper#getWrapped()
     * @since 2.0
     */
    public ResponseWriter getWrapped() {
        return writer;
    }

    /**
     * Write the start of a partial response.
     *
     * @throws IOException if an input/output error occurs
     * @since 2.0
     */
    public void startDocument() throws IOException {
        ResponseWriter writer = getWrapped();
        String encoding = writer.getCharacterEncoding( );
        if( encoding == null ) {
            encoding = "utf-8";
        }
        writer.writePreamble("\n");
        writer.startElement("partial-response", null);
        FacesContext ctx = FacesContext.getCurrentInstance();
        if (null != ctx && null != ctx.getViewRoot()) {
            String id = ctx.getViewRoot().getContainerClientId(ctx);
            writer.writeAttribute("id", id, "id");
        }
    }

    /**
     * Write the end of a partial response.
     *
     * @throws IOException if an input/output error occurs
     * @since 2.0
     */
    public void endDocument() throws IOException {
        endChangesIfNecessary();
        ResponseWriter writer = getWrapped();
        /*
         * Because during a