Multi language using visualforce with custom labels

Question

<apex:page id="thepage" controller="PageController1" language="{!IF(ISNULL(language),'en_US',language)}">
    <apex:form id="theform">
            <apex:commandlink action="{!changeEnglish}" rerender="thepage" value="English"/><br/>
<br/><br/>
        <apex:commandlink action="{!changeFrench}" rerender="thepage" value="French"/><br/><br/><br/>



        <apex:outputLabel value="{!$Label.french}" rendered="true" onclick="changeEnglish();"/><br/>
        <apex:outputLabel value="{!$Label.english}" rendered="true" onclick="changeFrench();"/><br/><br/><br/><br/>
        Text of page here
    </apex:form>
</apex:page>

Controller:

public with sharing class PageController1 {
public string language {get;set;}
public boolean isFrench {get;set;}

public void changeFrench(){
    language = 'fr';
     isFrench = true;
}

public void changeEnglish(){
    language = 'en_US';
        isFrench = false;

}

}

if i click on french only french language must appear from custom labels. by default english must enable?? how can i achieve it

Answer 1

This controller and page will do the language switching. I think the re-rendering you have specified is getting in the way; returning null from the action causes the entire page to refresh in any case which is what is needed.

public with sharing class MyController {

    public String language {get;set;}

    public PageReference toFrench() {
        language = 'fr';
        return null;
    }

    public PageReference toEnglish() {
        language = 'en_US';
        return null;
    }

    public MyController() {
        toEnglish();
    }
}

<apex:page language="{!language}" controller="MyController">
    <apex:form>
       <apex:commandlink action="{!toEnglish}" value="English"/>
       <br/>
       <apex:commandlink action="{!toFrench}" value="French"/>
       <br/>
       {!language}
       <br/>
       {!$ObjectType.Opportunity.label}
    </apex:form>
</apex:page>

(This is making use of the apex:page language attribute which takes precedence over the language defined for the user. In this example the only text that will change is the opportunity object label.)