How to use renderer feature easily?

Question

Hi, i have read a lot about renderers and i think it is much more complicated than converters and validator for example.
For example i would like that the inputText that come by default with jsf don't be gray but red. I know that i can fix its css attributes and every thing ok, but what i want is that when i pick on the component toolbar the inputText and drag it into the page the component shows itself red.
So, to do that i have to write a Renderer subclass, define a new jsp tag and its handler class, i think this is a lot of work just to change a default color.
There is another way to do that?
I think for instace, extend the default renderer class of the inputText component of jsf and in some way define the new color the component will be rendered.

Answer 1

Hi,
i had a similar problem. I wanted to render the rows and columns of my dataTable dependend on the underlying data. So i just did what you mentioned:
Extend the renderer for this component and decide what to do to its attributes.
Example:
public void encodeChildren(FacesContext context, UIComponent component)
        throws IOException
        if(context == null || component == null)
            throw new NullPointerException(Util.getExceptionMessageString("com.sun.faces.NULL_PARAMETERS_ERROR"));
        if(log.isDebugEnabled())
            log.debug("Begin encoding children " + component.getId());
        if(!component.isRendered())
        String columnClasses[] = getColumnClasses(data);
        int columnStyle = 0;
        int columnStyles = columnClasses.length;
        String AllrowClasses[] = getRowClasses(data);
        // Clean AllrowClasses for iteratable rowStyles (without 'Feiertage')
        String rowClasses[] = shiftStylesforActWeekday(AllrowClasses,data);
        do
            if(rows > 0 && ++processed > rows)
                break;
                // If act. row is 'Feiertag' include style for all columns for this row
                columnCount++;
    if ((tagN != null && !tagN.equalsIgnoreCase(""))|| (tagS != null && !tagS.equalsIgnoreCase("")&& isSaarWorker))
                if(columnStyles > 0)
                 writer.writeAttribute("class", columnClasses[columnStyle++], "columnClasses");
                 if(columnStyle >= columnStyles)
                  columnStyle = 0;
            // Insert extra row after "So"
            if (wtag.equalsIgnoreCase("So")){
             InsertExtraRow(writer, columnCount);
        } while(true);
...   I had to change the column and rowClasses array depending which row is first in dataTable. So i shift this array and the renderer uses the shifted array to style each row and column.
I hope that may help!? Regards,
ak