System
SelectOption consists of a label that is displayed to the end user, and a value that is returned to the controller if the option is selected. A SelectOption can also be displayed in a disabled state, so that a user cannot select it as an option, but can still view it.
SelectOption option = new SelectOption(value, label, isDisabled);
where value is the String that is returned to the controller if the option is selected by a user, label is the String that is displayed to the user as the option choice, and isDisabled is a Boolean that, if true, specifies that the user cannot select the option, but can still view it.
SelectOption option = new SelectOption(value, label);
where value is the String that is returned to the controller if the option is selected by a user, and label is the String that is displayed to the user as the option choice. Because a value for isDisabled is not specified, the user can both view and select the option.
The following example shows how a list of SelectOptions objects can be used to provide possible values for a selectCheckboxes component on a Visualforce page. In the following custom controller, the getItems method defines and returns the list of possible SelectOption objects:
public class sampleCon { String[] countries = new String[]{}; public PageReference test() { return null; } public List<SelectOption> getItems() { List<SelectOption> options = new List<SelectOption>(); options.add(new SelectOption('US','US')); options.add(new SelectOption('CANADA','Canada')); options.add(new SelectOption('MEXICO','Mexico')); return options; } public String[] getCountries() { return countries; } public void setCountries(String[] countries) { this.countries = countries; } }
In the following page markup, the <apex:selectOptions> tag uses the getItems method from the controller above to retrieve the list of possible values. Because <apex:selectOptions> is a child of the <apex:selectCheckboxes> tag, the options are displayed as checkboxes:
<apex:page controller="sampleCon"> <apex:form> <apex:selectCheckboxes value="{!countries}"> <apex:selectOptions value="{!items}"/> </apex:selectCheckboxes><br/> <apex:commandButton value="Test" action="{!test}" rerender="out" status="status"/> </apex:form> <apex:outputPanel id="out"> <apex:actionstatus id="status" startText="testing..."> <apex:facet name="stop"> <apex:outputPanel> <p>You have selected:</p> <apex:dataList value="{!countries}" var="c">{!c}</apex:dataList> </apex:outputPanel> </apex:facet> </apex:actionstatus> </apex:outputPanel> </apex:page>