UploadRenderer.java

/* MyMAM - Open Source Digital Media Asset Management.
 * http://www.mymam.net
 *
 * Copyright 2013, MyMAM contributors as indicated by the @author tag.
 *
 * Licensed 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 net.mymam.ui;

import net.mymam.upload.UploadMultipartRequestWrapper;
import org.apache.commons.fileupload.FileItem;

import javax.faces.component.EditableValueHolder;
import javax.faces.component.UIComponent;
import javax.faces.component.UIInput;
import javax.faces.context.FacesContext;
import javax.faces.context.ResponseWriter;
import javax.faces.render.FacesRenderer;
import javax.faces.render.Renderer;
import javax.servlet.ServletRequestWrapper;
import java.io.IOException;
import java.nio.charset.Charset;

/**
 * Renderer for the {@link Upload} component.
 *
 * <p/>
 * Most of the HTML rendered here is initially invisible, using <tt>style="display: none"</tt>.
 * The invisible tags are templates that are used by <tt>mymam-upload.js</tt>.
 *
 * @see Upload
 * @author fstab
 */
@FacesRenderer(componentFamily = UIInput.COMPONENT_FAMILY, rendererType = "net.mymam.ui.UploadRenderer")
public class UploadRenderer extends Renderer {

    @Override
    public void encodeBegin(FacesContext context, UIComponent component) throws IOException {
        if ( component.isRendered() ) {
            ResponseWriter writer = context.getResponseWriter();
            String clientId = component.getClientId(context);
            renderMainButtons(clientId, writer, (Upload) component);
            renderStatusMessageTemplates(writer, (Upload) component);
            renderGlobalStatusLineTemplate(writer, (Upload) component);
            renderUploadInfoTable(writer, (Upload) component);
        }
    }

    private void renderMainButtons(String clientId, ResponseWriter writer, Upload component) throws IOException {
        writer.startElement("div", component);
        writer.writeAttribute("class", "main-buttons", null);
        renderAddFilesButton(clientId, writer, component);
        renderClearButton(writer, component);
        renderSubmitButton(writer, component);
        writer.endElement("div");
    }

    private void renderAddFilesButton(String clientId, ResponseWriter writer, Upload component) throws IOException {
        writer.startElement("span", component);
        writer.writeAttribute("class", "btn fileinput-button btn-primary", null);
        writer.startElement("i", component);
        writer.writeAttribute("class", "icon-plus", null);
        writer.endElement("i");
        writer.startElement("span", component);
        writer.write(component.getAddFilesButtonLabel());
        writer.endElement("span");
        writer.startElement("input", component);
        writer.writeAttribute("type", "file", null);
        writer.writeAttribute("name", clientId, null);
        writer.writeAttribute("multiple", "multiple", null);
        writer.endElement("input");
        writer.endElement("span");
    }

    private void renderClearButton(ResponseWriter writer, Upload component) throws IOException {
        writer.startElement("input", component);
        writer.writeAttribute("type", "button", null);
        writer.writeAttribute("value", component.getClearButtonLabel(), null);
        writer.writeAttribute("class", "btn clear-button", null);
        writer.endElement("input");
    }

    private void renderSubmitButton(ResponseWriter writer, Upload component) throws IOException {
        writer.startElement("input", component);
        writer.writeAttribute("type", "button", null);
        writer.writeAttribute("value", component.getSubmitButtonLabel(), null);
        writer.writeAttribute("class", "btn submit-button", null);
        writer.endElement("input");
    }

    private void renderStatusMessageTemplates(ResponseWriter writer, Upload component) throws IOException {
        renderStatusMessageTemplate(writer, component, "alert alert-success upload-info-all-done", component.getSuccessMsgTemplate());
        renderStatusMessageTemplate(writer, component, "alert alert-block upload-info-all-warn", component.getWarnMsgTemplate());
        renderStatusMessageTemplate(writer, component, "alert alert-error upload-info-all-error", component.getErrorMsgTemplate());
    }

    private void renderStatusMessageTemplate(ResponseWriter writer, Upload component, String styleClass, String msg) throws IOException {
        writer.startElement("div", component);
        writer.writeAttribute("class", styleClass, null);
        writer.writeAttribute("style", "display: none", null);
        writer.startElement("button", component);
        writer.writeAttribute("type", "button", null);
        writer.writeAttribute("class", "close", null);
        writer.writeAttribute("data-dismiss", "alert", null);
        writer.write("×");
        writer.endElement("button");
        writer.write(msg);
        writer.endElement("div");
    }

    private void renderGlobalStatusLineTemplate(ResponseWriter writer, Upload component) throws IOException {
        writer.startElement("p", component);
        writer.writeAttribute("class", "upload-info-status lead", null);
        writer.startElement("span", component);
        writer.writeAttribute("style", "display: none;", null);
        writer.write(component.getGlobalStatusTemplate());
        writer.endElement("span");
        writer.endElement("p");
    }

    private void renderUploadInfoTable(ResponseWriter writer, Upload component) throws IOException {
        writer.startElement("table", component);
        writer.writeAttribute("class", "table table-striped", null);
        writer.startElement("tbody", component);
        writer.startElement("tr", component);
        writer.writeAttribute("style", "display: none", null);
        renderColumnOne(writer, component);
        renderColumnTwo(writer, component);
        renderColumnThree(writer, component);
        renderColumnFour(writer, component);
        writer.endElement("tr");
        writer.endElement("tbody");
        writer.endElement("table");
    }

    private void renderColumnOne(ResponseWriter writer, Upload component) throws IOException {
        writer.startElement("td", component);
        writer.writeAttribute("class", "upload-info-line-number", null);
        writer.write("1");
        writer.endElement("td");
    }

    private void renderColumnTwo(ResponseWriter writer, Upload component) throws IOException {
        writer.startElement("td", component);
        writer.writeAttribute("class", "upload-info-file-name", null);
        writer.startElement("div", component);
        writer.write("video.mov");
        writer.endElement("div");
        writer.startElement("div", component);
        writer.writeAttribute("class", "progress progress-striped", null);
        writer.startElement("div", component);
        writer.writeAttribute("class", "bar", null);
        writer.writeAttribute("style", "width: 0%;", null);
        writer.endElement("div");
        writer.endElement("div");
        writer.endElement("td");
    }

    private void renderColumnThree(ResponseWriter writer, Upload component) throws IOException {
        writer.startElement("td", component);
        writer.writeAttribute("class", "upload-info-file-size", null);
        writer.write("1.5M");
        writer.endElement("td");
    }

    private void renderColumnFour(ResponseWriter writer, Upload component) throws IOException {
        writer.startElement("td", component);
        writer.writeAttribute("class", "upload-info-status-column", null);
        renderRemoveButton(writer, component);
        renderLabel(writer, component, "label label-info upload-info-status-uploading", "icon-arrow-up", component.getUploadingLabel());
        renderLabel(writer, component, "label label-success upload-info-status-done", "icon-ok-sign", component.getDoneLabel());
        renderLabel(writer, component, "label label-important upload-info-status-failed", "icon-warning-sign", component.getFailedLabel());
        writer.endElement("td");
    }

    private void renderRemoveButton(ResponseWriter writer, Upload component) throws IOException {
        writer.startElement("button", component);
        writer.writeAttribute("class", "btn upload-info-status-remove", null);
        writer.startElement("i", component);
        writer.writeAttribute("class", "icon-remove-circle", null);
        writer.endElement("i");
        writer.startElement("span", component);
        writer.write(" " + component.getRemoveButtonLabel());
        writer.endElement("span");
        writer.endElement("button");
    }

    private void renderLabel(ResponseWriter writer, Upload component, String styleClass, String icon, String msg) throws IOException {
        writer.startElement("span", component);
        writer.writeAttribute("class", styleClass, null);
        writer.writeAttribute("style", "display: none;", null);
        writer.startElement("i", component);
        writer.writeAttribute("class", icon, null);
        writer.endElement("i");
        writer.startElement("span", component);
        writer.write(" " + msg);
        writer.endElement("span");
        writer.endElement("span");
    }

    /**
     * Handle the postback of a form containing an {@link Upload} component.
     *
     * <p/>
     * If the request contains a {@link FileItem}, set the corresponding
     * value in the backing bean.
     *
     * @param context {@link FacesContext} for the request we are processing.
     * @param component {@link UIComponent} to be decoded.
     */
    @Override
    public void decode(FacesContext context, UIComponent component) {
        UploadMultipartRequestWrapper requestWrapper = getMultiPartRequestInChain(context);
        if (requestWrapper != null) { // if we are processing a multipart request
            String clientId = component.getClientId(context);
            FileItem fileItem = requestWrapper.getFileItem(clientId);
            if (fileItem != null) { // if the multipart request has a file item
                String encoding = findEncoding(requestWrapper);
                UploadedFile uploadedFile = new UploadedFile(fileItem, encoding);
                ((EditableValueHolder) component).setSubmittedValue(uploadedFile);
                ((EditableValueHolder) component).setValid(true);
            }
        }
    }

    // Either the encoding is sent in the request, or we take the JVM's default encoding.
    private String findEncoding(UploadMultipartRequestWrapper request) {
        String encoding = request.getCharacterEncoding();
        if ( encoding == null ) {
            encoding = System.getProperty("file.encoding");
        }
        if ( encoding == null ) {
            encoding = Charset.defaultCharset().toString();
        }
        return encoding;
    }

    // Finds our MultipartRequestServletWrapper in case application contains other RequestWrappers.
    // This method is taken from PrimeFaces' implementation.
    private UploadMultipartRequestWrapper getMultiPartRequestInChain(FacesContext facesContext) {
        Object request = facesContext.getExternalContext().getRequest();
        while (request instanceof ServletRequestWrapper) {
            if (request instanceof UploadMultipartRequestWrapper) {
                return (UploadMultipartRequestWrapper) request;
            } else {
                request = ((ServletRequestWrapper) request).getRequest();
            }
        }
        return null;
    }

}