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Wednesday, March 30, 2016

Conditionally display row using JSF Datatable

Conditionally display row using JSF Datatable


I have some JSF code that currently works (as shown below), and I need to modify it to conditionally suppress the display of certain rows of the table. I know how to conditionally suppress the display of a particular cell, but that seems to create an empty cell, while what I'm trying to do is to not display the row at all.

Any suggestions?

                                                                     

Basically, the line that says #{com.rendered} will conditionally display the contents of a single cell, producing an empty cell when com.rendered is false. But I want to skip an entire row of the display under certain conditions - how would I go about doing that?

Answer by Naganalf for Conditionally display row using JSF Datatable


Rows correspond to data objects in the collection of your table. If you don't want the row, don't put the object in the collection.

Alternatively, you can use the rowClasses parameter for dataTable.

Bean code:

public String getRowClasses() {      StringBuilder sb = new StringBuilder();      for (Data data : myData) {          sb.append(data.hide ? 'hide,' : 'show,');      }      return sb.toString();  }  

CSS:

tr.hide {display:none;}  

Answer by Brian Leathem for Conditionally display row using JSF Datatable


I've successfully hidden rows by putting a rendered attribute in all the tags. The problem is that it suppresses the table headers. You're table has no table headers (they are tags embedded in the ), so this approach might work for you.

I ended up using multiple lists in the backing bean, as I needed the table headers.

Answer by Ernst-Jan for Conditionally display row using JSF Datatable


For people using richFaces, you can use rich:column's filterExpression attribute.

      ...    

If the condition is not met, the complete row is filtered out.

Example is using seam EL!

Answer by sanjay for Conditionally display row using JSF Datatable


extension to Brian's solution. To display the column names I did the following in primefaces

                                                                                                                                                                     

Answer by David Wang for Conditionally display row using JSF Datatable


I extend HtmlTableRenderer default renderer and overwrite renderRowStart method to achieve this by giving style attribute into table->tr element with value display:none.

The item inside binding list needs to implement TableRow interface which only has one method of isHide. In the concrete class you can put any logic you like to give a boolean value.

BTW, in this custom renderer also has PrimeFaces implementation like function which gives the message when table is empty and the table->tr will automatically calculate how many columns in the table and give proper value to colspan attribute.

public class MyDataTableRenderer extends HtmlTableRenderer {      private static final Integer[] ZERO_INT_ARRAY = new Integer[] { 0 };      private static final String NO_RESULT_MESSAGE_ATTR_NAME = "noResultMessage";      private static final String defaultEmptyMessage = "No records found";      private static final Logger log = Logger.getLogger(DHSDataTableRenderer.class.getName());    @Override  public void encodeInnerHtml(FacesContext facesContext, UIComponent component) throws IOException {      UIData uiData = (UIData) component;      String message = (String) uiData.getAttributes().get(NO_RESULT_MESSAGE_ATTR_NAME);      if (message == null || "".equals(message.trim())) {          message = defaultEmptyMessage;      }        ResponseWriter writer = facesContext.getResponseWriter();        int rowCount = uiData.getRowCount();        int newspaperColumns = getNewspaperColumns(component);        int columnNumber = getChildCount(component);        if (rowCount == -1 && newspaperColumns == 1) {          encodeInnerHtmlUnknownRowCount(facesContext, component);          return;      }        if (rowCount == 0) {          // nothing to render, to get valid xhtml we render an empty dummy          // row          writer.startElement(HTML.TBODY_ELEM, uiData);          writer.writeAttribute(HTML.ID_ATTR, component.getClientId(facesContext) + ":tbody_element", null);          writer.startElement(HTML.TR_ELEM, uiData);          writer.startElement(HTML.TD_ELEM, uiData);          writer.writeAttribute(HTML.COLSPAN_ATTR, columnNumber, null);          writer.writeAttribute(HTML.CLASS_ATTR, "dhs-empty-table", null);          writer.write(message);          writer.endElement(HTML.TD_ELEM);          writer.endElement(HTML.TR_ELEM);          writer.endElement(HTML.TBODY_ELEM);          return;      }        // begin the table      // get the CSS styles      Styles styles = getStyles(uiData);        int first = uiData.getFirst();      int rows = uiData.getRows();      int last;        if (rows <= 0) {          last = rowCount;      } else {          last = first + rows;          if (last > rowCount) {              last = rowCount;          }      }        int newspaperRows;      if ((last - first) % newspaperColumns == 0) {          newspaperRows = (last - first) / newspaperColumns;      } else {          newspaperRows = ((last - first) / newspaperColumns) + 1;      }      boolean newspaperHorizontalOrientation = isNewspaperHorizontalOrientation(component);        // get the row indizes for which a new TBODY element should be created      Integer[] bodyrows = getBodyRows(facesContext, component);      int bodyrowsCount = 0;        // walk through the newspaper rows      for (int nr = 0; nr < newspaperRows; nr++) {          boolean rowStartRendered = false;          // walk through the newspaper columns          for (int nc = 0; nc < newspaperColumns; nc++) {                // the current row in the 'real' table              int currentRow;              if (newspaperHorizontalOrientation) {                  currentRow = nr * newspaperColumns + nc + first;              } else {                  currentRow = nc * newspaperRows + nr + first;              }                // if this row is not to be rendered              if (currentRow >= last) {                  continue;              }                // bail if any row does not exist              uiData.setRowIndex(currentRow);              if (!uiData.isRowAvailable()) {                  log.severe("Row is not available. Rowindex = " + currentRow);                  break;              }                if (nc == 0) {                  // first column in table, start new row                  beforeRow(facesContext, uiData);                    // is the current row listed in the bodyrows attribute                  if (ArrayUtils.contains(bodyrows, currentRow)) {                      // close any preopened TBODY element first                      if (bodyrowsCount != 0) {                          HtmlRendererUtils.writePrettyLineSeparator(facesContext);                          writer.endElement(HTML.TBODY_ELEM);                      }                      HtmlRendererUtils.writePrettyLineSeparator(facesContext);                      writer.startElement(HTML.TBODY_ELEM, uiData);                      // Do not attach bodyrowsCount to the first TBODY                      // element, because of backward compatibility                      writer.writeAttribute(HTML.ID_ATTR, component.getClientId(facesContext) + ":tbody_element" + (bodyrowsCount == 0 ? "" : bodyrowsCount),                              null);                      bodyrowsCount++;                  }                    HtmlRendererUtils.writePrettyLineSeparator(facesContext);                  renderRowStart(facesContext, writer, uiData, styles, nr);                  rowStartRendered = true;              }                List children = null;              for (int j = 0, size = getChildCount(component); j < size; j++) {                  if (children == null) {                      children = getChildren(component);                  }                  UIComponent child = children.get(j);                  if (child.isRendered()) {                      boolean columnRendering = child instanceof UIColumn;                        if (columnRendering) {                          beforeColumn(facesContext, uiData, j);                      }                        encodeColumnChild(facesContext, writer, uiData, child, styles, nc * uiData.getChildCount() + j);                        if (columnRendering) {                          afterColumn(facesContext, uiData, j);                      }                  }              }                if (hasNewspaperTableSpacer(uiData)) {                  // draw the spacer facet                  if (nc < newspaperColumns - 1) {                      renderSpacerCell(facesContext, writer, uiData);                  }              }          }          if (rowStartRendered) {              renderRowEnd(facesContext, writer, uiData);              afterRow(facesContext, uiData);          }      }        if (bodyrowsCount != 0) {          // close the last TBODY element          HtmlRendererUtils.writePrettyLineSeparator(facesContext);          writer.endElement(HTML.TBODY_ELEM);      }  }    @Override  protected void renderRowStart(FacesContext facesContext, ResponseWriter writer, UIData uiData, Styles styles, int rowStyleIndex) throws IOException {      writer.startElement(HTML.TR_ELEM, null); // uiData);        renderRowStyle(facesContext, writer, uiData, styles, rowStyleIndex);      Object obj = uiData.getRowData();      boolean isHide = false;      if (obj instanceof TableRow) {          isHide = ((TableRow) obj).isHide();      }      if (isHide) {          writer.writeAttribute("style", "display: none;", null);      }      Object rowId = uiData.getAttributes().get(org.apache.myfaces.shared.renderkit.JSFAttr.ROW_ID);        if (rowId != null) {          writer.writeAttribute(HTML.ID_ATTR, rowId.toString(), null);      }  }    private void encodeInnerHtmlUnknownRowCount(FacesContext facesContext, UIComponent component) throws IOException {      UIData uiData = (UIData) component;      ResponseWriter writer = facesContext.getResponseWriter();        Styles styles = getStyles(uiData);        Integer[] bodyrows = getBodyRows(facesContext, component);      int bodyrowsCount = 0;        int first = uiData.getFirst();      int rows = uiData.getRows();      int currentRow = first;      boolean isRowRendered = false;        while (true) {          uiData.setRowIndex(currentRow);          if (!uiData.isRowAvailable()) {              break;          }            isRowRendered = true;            // first column in table, start new row          beforeRow(facesContext, uiData);            // is the current row listed in the bodyrows attribute          if (ArrayUtils.contains(bodyrows, currentRow)) {              // close any preopened TBODY element first              if (bodyrowsCount != 0) {                  HtmlRendererUtils.writePrettyLineSeparator(facesContext);                  writer.endElement(HTML.TBODY_ELEM);              }              HtmlRendererUtils.writePrettyLineSeparator(facesContext);              writer.startElement(HTML.TBODY_ELEM, uiData);              // Do not attach bodyrowsCount to the first TBODY element,              // because of backward compatibility              writer.writeAttribute(HTML.ID_ATTR, component.getClientId(facesContext) + ":tbody_element" + (bodyrowsCount == 0 ? "" : bodyrowsCount), null);              bodyrowsCount++;          }            HtmlRendererUtils.writePrettyLineSeparator(facesContext);          renderRowStart(facesContext, writer, uiData, styles, currentRow);            List children = null;          for (int j = 0, size = getChildCount(component); j < size; j++) {              if (children == null) {                  children = getChildren(component);              }              UIComponent child = children.get(j);              if (child.isRendered()) {                  boolean columnRendering = child instanceof UIColumn;                    if (columnRendering) {                      beforeColumn(facesContext, uiData, j);                  }                    encodeColumnChild(facesContext, writer, uiData, child, styles, j);                    if (columnRendering) {                      afterColumn(facesContext, uiData, j);                  }              }          }            renderRowEnd(facesContext, writer, uiData);          afterRow(facesContext, uiData);            currentRow++;            if (rows > 0 && currentRow - first > rows) {              break;          }      }        if (!isRowRendered) {          // nothing to render, to get valid xhtml we render an empty dummy          // row          writer.startElement(HTML.TBODY_ELEM, uiData);          writer.writeAttribute(HTML.ID_ATTR, component.getClientId(facesContext) + ":tbody_element", null);          writer.startElement(HTML.TR_ELEM, uiData);          writer.startElement(HTML.TD_ELEM, uiData);          writer.endElement(HTML.TD_ELEM);          writer.endElement(HTML.TR_ELEM);          writer.endElement(HTML.TBODY_ELEM);          return;      }        if (bodyrowsCount != 0) {          // close the last TBODY element          HtmlRendererUtils.writePrettyLineSeparator(facesContext);          writer.endElement(HTML.TBODY_ELEM);      }  }    private Integer[] getBodyRows(FacesContext facesContext, UIComponent component) {      Integer[] bodyrows = null;      String bodyrowsAttr = (String) component.getAttributes().get(JSFAttr.BODYROWS_ATTR);      if (bodyrowsAttr != null && !"".equals(bodyrowsAttr)) {          String[] bodyrowsString = StringUtils.trim(StringUtils.splitShortString(bodyrowsAttr, ','));          // parsing with no exception handling, because of JSF-spec:          // "If present, this must be a comma separated list of integers."          bodyrows = new Integer[bodyrowsString.length];          for (int i = 0; i < bodyrowsString.length; i++) {              bodyrows[i] = new Integer(bodyrowsString[i]);          }        } else {          bodyrows = ZERO_INT_ARRAY;      }      return bodyrows;  }  

}


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