rich:columns columns

Component identification parameters

Name | Value
--- | ---
component-type | org.richfaces.Column
tag-class | org.richfaces.taglib.ColumnsTagHandler

## Creating the Component with a Page Tag

To create the simplest variant on a page use the following syntax:

Example:

    ...
    <rich:dataTable value="#{capitalsBean.capitals}" var="cap">
            <rich:columns value="#{capitalsBean.labels}" var="col" index="index">
                    <h:outputText value="#{cap[index]}" />
            </rich:columns>
    </rich:dataTable>
    ...

## Creating the Component Dynamically Using Java

Example:

    import org.richfaces.component.html.HtmlColumn;
    ...
    HtmlColumn myColumns = new HtmlColumn();
    ...

## Details of Usage

The <rich:columns> component gets a list from data model and outputs corresponding set of columns inside <rich:dataTable> on a page. It is possible to use "header" and "footer" facets with <rich:columns> component.

The "value" and "var" attributes are used to access the values of collection.

The simple example is placed below.

Example:

    ...
    <rich:dataTable value="#{capitalsBean.capitals}" var="cap">
            <rich:columns value="#{capitalsBean.labels}" var="col" index="index">
                    <f:facet name="header">
                            <h:outputText value="#{col.text}" />
                    </f:facet>
    	     <h:outputText value="#{cap[index]}" />
    	     <f:facet name="footer">
    	             <h:outputText value="#{col.text}" />
    	     </f:facet>
            </rich:columns>
    </rich:dataTable>
    ...

The "columns" attribute defines the count of columns.

The "rowspan" attribute defines the number of rows to be displayed. If the value of this attribute is zero, all remaining rows in the table are displayed on a page.

The "begin" attribute contains the first iteration item. Note, that iteration begins from zero.

The "end" attribute contains the last iteration item.

With the help of the attributes described below you can customize the output, i.e. define which columns and how many rows appear on a page.

Example:

    ...
    <rich:dataTable value="#{capitalsBean.capitals}" var="cap">
            <rich:columns value="#{capitalsBean.labels}" var="col" index="index" rowspan="0" columns="3" begin="1" end="2">
                    <f:facet name="header">
                            <h:outputText value="#{col.text}" />
                    </f:facet>
                    <h:outputText value="#{cap[index]}" />
            </rich:columns>
    </rich:dataTable>
    ...

In the example below, columns from first to second and all rows are shown in the <rich:dataTable> .

The result is:

Generated <rich:columns> with columns from first to second and all rows

The <rich:columns> component does not prevent to use <rich:column> . In the following example one column renders in any way and another columns could be picked from the model.

Example:

    ...
    <rich:dataTable value="#{rowBean.rows}" var="row">
            <rich:column>
                    <h:outputText value ="#{row.columnValue}"/>
            </rich:column>
            <rich:columns value="#{colBean.columns}" var="col">
                    <f:facet name="header">
                            <h:outputText value="#{col.header}"/>
                    </f:facet>
                    <h:outputText value="#{row.columnValue}"/>
                    <f:facet name="footer">
                            <h:outputText value="#{col.footer}"/>
                    </f:facet>
            </rich:columns>
    </rich:dataTable>
    ...

Now, you can use a few <rich:columns> together with <rich:column> within the one table:

    ...
    <rich:dataTable value="#{dataTableScrollerBean.model}" var="model" width="500px" rows="5">
              <f:facet name="header">
    	          <h:outputText value="Cars Available"></h:outputText>
    	</f:facet>
    	<rich:columns value="#{dataTableScrollerBean.columns}" var="columns" index="ind">
    	          <f:facet name="header">
    		          <h:outputText value="#{columns.header}" />
    		</f:facet>
    		<h:outputText value="#{model[ind].model} " />
    	</rich:columns>
    	<rich:column>
    		<f:facet name="header">
    		          <h:outputText value="Price" />
    		</f:facet>
                        <h:outputText value="Price" />
    	</rich:column>
    	<rich:columns value="#{dataTableScrollerBean.columns}" var="columns" index="ind">
    	          <f:facet name="header">
    		          <h:outputText value="#{columns.header}" />
    		</f:facet>
    		<h:outputText value="#{model[ind].mileage}$" />
    	</rich:columns>
    </rich:dataTable>
    ...

In order to group columns with text information into one row, use the "colspan" attribute, which is similar to an HTML one. In the following example the third column contains 3 columns. In addition, it's necessary to specify that the next column begins from the first row with the help of the `breakBefore = "true"` .

Example:

    ...
    <rich:dataTable value="#{columns.data1}" var="data">
            <rich:column>
                    <h:outputText value="#{column.Item1}" />
            </rich:column>
            <rich:column>
                    <h:outputText value="#{column.Item2}" />
            </rich:column>
            <rich:column>
                    <h:outputText value="#{column.Item3}" />
            </rich:column>
            <rich:columns columns="3" colspan="3" breakBefore="true">
                    <h:outputText value="#{data.str0}" />
            </rich:columns>
    </rich:dataTable>
    ...

The same way is used for columns grouping with the "rowspan" attribute that is similar to an HTML. The only thing to add in the example is an instruction to move onto the next row for each next after the second column.

Example:

    ...
    <rich:dataTable value="#{columns.data1}" var="data">
            <rich:columns columns="2" rowspan="3">
                    <h:outputText value="#{data.str0}" />
            </rich:columns>
            <rich:column>
                    <h:outputText value="#{column.Item1}" />
            </rich:column>
            <rich:column  breakBefore="true">
                    <h:outputText value="#{column.Item2}" />
            </rich:column>
            <rich:column  breakBefore="true">
                    <h:outputText value="#{column.Item3}" />
            </rich:column>
    </rich:dataTable>
    ...

Note:

The <rich:columns> tag is initialized during components tree building process. This process precedes page rendering at "Render Response" JSF phase. To be rendered properly the component needs all it variables to be initialized while the components tree is being building. A javax.servlet.jsp.JspTagException occurs if <rich:columns> uses variables passed from other components, if these variables are initialized during rendering. Thus, when <rich:columns> is asking for such variables they do not already exist. Use <c:forEach> JSP standard tag as workaround. Compare two examples below.

This code calls the exception:

    ...
    <rich:dataTable value="#{bean.data}" var="var">
              <rich:columns value="#{var.columns}">
                        ...
              </rich:columns>
    </rich:dataTable>
    ...

This code works properly:

    ...
    <c:forEach items="#{bean.data}" var="var">
              <rich:columns value="#{var.columns}">
                        ...
              </rich:columns>
    </c:forEach>
    ...

Note:

Since 3.3.0GA <rich:columns> requires explicit definition of "id" for children components to ensure that decode process works properly. The example of how you can define unique "id" for children component:

    ...
    <rich:columns value="#{bean.columns}" var="col" index="ind" ....>
    <h:inputText id="input#{ind}" value="">
    <a4j:support id="support#{ind}" event="onchange" reRender="someId" />
    </h:inputText>
    </rich:columns>
    ...

Only if "id" defined as shown above Ajax after onchange event will be processed as expected.

Information about sorting and filtering you can find in the corresponding section .

## Facets

Facets

Facet name | Description
--- | ---
header | Defines the header content
footer | Defines the footer content

## Look-and-Feel Customization

For skinnability implementation, the components use a style class redefinition method. Default style classes are mapped on skin parameters.

There are two ways to redefine the appearance of all <rich:columns> components at once:

- Redefine the corresponding skin parameters

- Add to your style sheets style classes used by a <rich:columns> component

## Skin Parameters Redefinition

Skin parameters redefinition for <rich:columns> are the same as for the <rich:dataTable> component .

## Definition of Custom Style Classes

Custom style classes for <rich:columns> are the same as for the <rich:dataTable> component .

In order to redefine styles for all <rich:columns> components on a page using CSS, it's enough to create classes with the same names (possible classes could be found in the tables above ) and define necessary properties in them.

Example:

    ...
    .rich-table-subheadercell{
            color: #a0a0a0;
    }
    ...

This is a result:

Redefinition styles with predefined classes

In the example column header cells color was changed.

Also it's possible to change styles of particular <rich:columns> component. In this case you should create own style classes and use them in corresponding <rich:columns> styleClass attributes. An example is placed below:

Example:

    ...
    .myClass {
            font-style: oblique;
    }
    ...

The "styleClass" attribute for <rich:columns> is defined as it's shown in the example below:

Example:

    <rich:columns  styleClass="myClass">

This is a result:

Redefinition styles with own classes and styleClass attributes

As it could be seen on the picture above, the font style for columns was changed.

## Relevant Resources Links

On the component LiveDemo page you can found some additional information for <rich:columns> component usage.