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.HtmlColumns;
    ...
    HtmlColumns myColumns = new HtmlColumns();
    ...

## 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 "rows" 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" rows="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>

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>
    ...

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" attribute = 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>
    ...

Information about sorting and filtering you can find here.

## 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 and define necessary properties in them.

To change styles of particular <rich:columns> components, define your own style classes in the corresponding <rich:columns> attributes.

## Relevant Resources Links

Here you can found some additional information for <rich:columns> component usage.