Data Access On VF Page From Custom Component

                              

In a scenario I was using a custom component on a custom visualforce page. That custom component was containing pick list and populating data from component controller using dynamic soql query.

But the case was that I need to access pick list selected value on page side. I did little bit struggle with it but final get way that is following :-

<apex:component controller="LookUpListUtil">

<apex:attribute type="string" assignTo="{!QueryObject}" name="LookUpObject" description="Pick list data query on which object." required="true"/>

<apex:attribute type="string" assignTo="{!labelField}" default="name" name="label" description="which field of LookUpObject you want to populate in pick list " required="true"/>

<apex:attribute type="sobject" assignTo="{!objAssignTo}" name="AssignToObject" description="Object name on which you want to set selected value of pick list " required="true" />

<apex:attribute type="string" assignTo="{!AssignToField}" name="AssignToFieldname" description="field name of objAssignTo Object on which you want to set selected value of pick list " required="true" />

  

    <apex:selectList id="LookUpControl" value="{!PicklistData()}"    size="1" multiselect="false" >

        <apex:selectOption itemValue="" itemLabel="--Please Select--"/>

        <apex:selectoptions value="{!LookUpDataList}" >

    

    </apex:selectoptions>

 <apex:actionSupport event="onchange"  action="{!onValuechange}" rerender="sdf" />

</apex:selectList>

// Custom controller for lookup control. 

public with sharing class LookUpListUtil 

{

   

    

  

    public string QueryObject{get;set;}

    public string labelField{get;set;}

    public string groupBy{get;set;}

    

    public List<selectOption> LookUpDataList{get; private set;}

    

    public string lookUpSelectedValue{get;set;}

    public sobject objAssignTo{get;set ;}

    public string AssignToField{get;set;}

    

    public new  List<selectOption> GetPicklistData()

    {

        LookUpDataList=new  List<selectOption>();

        try

        {

// fetching to populate in pick list

            string soqlQuery;

            if(groupBy=='')

                soqlQuery='SELECT ID,'+labelField+' FROM '+ type.forname(QueryObject).getName();

            else 

                soqlQuery='SELECT ID,'+labelField+','+ groupBy+' FROM '+ type.forname(QueryObject).getName()+' ORDER BY '+groupBy;

             string itemVal;

                for(sobject obj:DataBase.query(soqlQuery))

                {

                    if(groupBy=='')

                        LookUpDataList.Add(new selectOption(string.ValueOf(obj.get('id')),string.Valueof(obj.get(labelField))));

                    else

                    {

                       itemVal=string.Valueof(obj.get(groupBy))+'_'+string.Valueof(obj.get(labelField));

                       LookUpDataList.Add(new selectOption(string.ValueOf(obj.get('id')),itemVal));

                    }

                }

             

         }

         catch(exception ex)

         {

              apexPages.AddMessage(new apexPages.Message(ApexPages.severity.Error,'Can\'t able to fetch data in PickList. There is an issue. '+ex.getmessage()));

         }

    }

    

    public void onValuechange()

    {

try

{

        objAssignTo.put(AssignToField,lookUpSelectedValue);

}

catch(exception ex)

         {

              apexPages.AddMessage(new apexPages.Message(ApexPages.severity.Error, ex.getmessage()));

         }

        

    }

  

   

}

Here I am using parameters in custom component which is objAssignTo  and AssignToField 

objAssignTo  is sobject data type parameters. And updating value in sobject's field. which is passing from vf page. So I am able to access values on vf page from custom component. 

<apex:page controller="LookUpListUtilTestPagecontroller" >

  <br/> <br/>

  <apex:form >

  <c:LookUp LookUpObject="Account" AssignToObject="{!acc}" AssignToFieldname="name" label ="name"/>

  

  <br/>

   

  <apex:commandButton action="{!Button_click}" title="Button" style="width:50px;"  value="Page Btn"> </apex:commandButton>

</apex:form>

</apex:page>

public with sharing class LookUpListUtilTestPagecontroller 

{

    public LookUpListUtilTestPagecontroller ()

    {

        acc=new account();

    }

    public account acc{get;set;}

    public pagereference Button_click()

    {

        

   

       system.assert(false,' Selected value is ='+acc.name);

        return null;

    }

    

  

    public LookUpListUtilTestPagecontroller GetThis(){ return this;}

}