Return specific fields for sObject List

Question

How can I control the getFieldTypeOptions method to return specific fields. In this case itreturns all available fields. Lets say I want only field name fieldName1 and fieldName2

public with sharing class MassUpdateSimpleController {

   private final ApexPages.StandardSetController cntr;
   private final PageReference fromPage;
   private final List<SObject> objs;
   private Map<String, Schema.SObjectField> fieldMap;
   private transient ApexPages.Message currentMsg;
   private final String newLine ='<br></br>';
   private Schema.SObjectField field;
   private String sType;
   private Object convertedFieldData;
   private List<SelectOption> picklistValues;
   private String currentStep;


   public MassUpdateSimpleController(ApexPages.StandardSetController controller) {
       currentStep = '1';
       controller.setPageSize(1000);
       cntr = (ApexPages.StandardSetController)controller;
       fromPage = cntr.cancel();
       if (this.objs == null) {
            this.objs = (List<SObject>)cntr.getSelected();
       }
       if (getRecordSize()<1) {
            String msg = 'No record was selected on the list view.  Please click Previous button and select records for mass update.'; 
            currentMsg = new ApexPages.Message(ApexPages.severity.ERROR, msg);
       } else {
            sType= discoverSObjectType(objs.get(0)).getName(); 
            String msg = 'Number of records selected for update: ' + getRecordSize(); 
            currentMsg = new ApexPages.Message(ApexPages.severity.INFO, msg);
       }
       ApexPages.addMessage(currentMsg);


   }


   /* public MassUpdateSimpleController() {
       System.debug('ids: ' + ApexPages.currentPage().getParameters().get('ids'));
       selected = ApexPages.currentPage().getParameters().get('id0');
       return; 
       cntr = new ApexPages.StandardSetController(objs);
       fromPage = cntr.cancel();
       if (this.objs == null) {
            this.objs = (List<SObject>)cntr.getSelected();
       }
       if (getRecordSize()<1) {
            String msg = 'No record was selected on the list view.  Please click Previous button and select records for mass update.'; 
            currentMsg = new ApexPages.Message(ApexPages.severity.ERROR, msg);
       } else {
            sType= discoverSObjectType(objs.get(0)).getName(); 
            String msg = 'Number of records selected for update: ' + getRecordSize(); 
            currentMsg = new ApexPages.Message(ApexPages.severity.INFO, msg);
       }
       ApexPages.addMessage(currentMsg);
   } */


    public String getStep() {
        return currentStep;
    }

    public String getsType() {
        return sType;
    }      

    public integer getRecordSize() {
     if (objs!=null) {
        return objs.size();
     } else {
        return 0;
     }
    }

    public String filterId {
        get;
        set;    
    }


    public String getNow(Boolean bShowTime) {
        DateTime now = DateTime.now();
        if (bShowTime)
            return  now.year() + '-' + now.month()+ '-' + now.day()+' '+now.hour()+ ':' +now.minute() + ':' + now.second();
        else
            return  now.year() + '-' + now.month()+ '-' + now.day();
    }

    public List<SObject> objsToUpdate {
        get {
            return (List<SObject>) cntr.getSelected();
        }
        set;
    }

    public String valueToUpdate {
        get;
        set;    
    }

    public String fieldName {
        get;
        set {
            fieldName=value;
            field = fieldMap.get(value);
            fieldType = field.getDescribe().getType().name();
        }   
    }

    public String fieldType{
        get;
        set;    
    }

    private Object convertUserInputToFieldData(){
        if (field==null) return null;
        DisplayType t = field.getDescribe().getType();
        Object s = null;

        try {       
                if (t==DisplayType.Double||t==DisplayType.Currency || t==DisplayType.Integer || t==DisplayType.Percent){
                    s = decimal.valueOf((String)valueToupdate);         
                } else if (t==DisplayType.Boolean){                 
                    if (valueToUpdate=='true'){
                        s = true;               
                    } else if (valueToUpdate=='false'){
                        s = false;              
                    } else {
                        s = Boolean.valueOf(valueToUpdate);
                    }
                } else if (t==DisplayType.Date) {
                    s = Date.valueOf(valueToUpdate);
                } else if (t==DisplayType.DateTime) {
                    s = DateTime.valueOf(valueToUpdate);
                } else if ((t==DisplayType.PickList || t==DisplayType.PickList) && valueToUpdate==null) {
                    s = '';
                }else {
                    s = valueToupdate;
                }
        } catch (System.TypeException e){
            System.debug('Type exception: ' + e.getMessage());
            currentMsg = new ApexPages.Message(ApexPages.severity.ERROR, e.getMessage());
            return null;
        }  

        return s;
    }


    public String getFieldInfoToDisplay() {
        if (field==null) return '';
        String msg = 'Field type of selected field: ' + fieldType + newline;

        Schema.DescribeFieldResult d = field.getDescribe();

        if (d.getType()==DisplayType.TextArea || d.getType()==(DisplayType.String)||d.getType()==(DisplayType.URL)) {
            msg += 'Max lengh: ' + d.getLength();
            valueToUpdate='';
        } else if (d.getType()==DisplayType.DateTime ){
            msg += 'Format: yyyy-MM-dd HH:mm:ss';
            valueToUpdate=getNow(true);
        } else if (d.getType()==DisplayType.Date){
            msg += 'Format: yyyy-MM-dd';
            valueToUpdate=getNow(false);
        } else if (d.getType()==DisplayType.Picklist){

            picklistValues = new List<SelectOption>();      
            if (d.isNillable()) {
                picklistValues.add(new SelectOption('', '--None--'));
            }
            for (Schema.PicklistEntry p : d.getPickListValues()) {
                picklistValues.add(new SelectOption(p.getValue(), p.getLabel()));
            }
            msg += newline + 'Please select a picklist value';
        } else if (d.getType()==DisplayType.MultiPicklist){

            msg += 'Valid Picklist Values: ';
            String combined ='';

            for (Schema.PicklistEntry p : d.getPickListValues()) {
                msg += newLine + '&nbsp;&nbsp;&nbsp;&nbsp;<b>' +p.getValue()+'</b>';
                combined += p.getValue()+';';
            }
            msg += newline + 'Use ; to seperate each picklist value you want to select';
            msg += newline + 'For example, to select all the picklist values, enter <b>' + combined + '</b> in the textbox below to select all picklist values';
        } else if (d.getType()==DisplayType.Integer){
            msg += 'Max digits: ' + d.getDigits();
        } else if (d.getType()==DisplayType.String){
            msg += 'Max length: ' + d.getLength();
        } else if (d.getType()==DisplayType.Double || d.getType()==DisplayType.Currency || d.getType()==DisplayType.Percent){
            msg += 'Format: (' + (d.getPrecision()-d.getScale()) + ','+d.getScale() +')';
        } else if (d.getType()==DisplayType.Reference){
            msg += 'Use this to change selected records to reference a different record, or even dereference records if the filed is left blank' + newLine;
            msg += 'Please enter ' + d.getName() + ' that the selected records should reference to';
        }

        return msg;
    }


    public PageReference cancel() {
        return fromPage;
    }

    public PageReference step1() { 
        currentStep='1';         
        return ApexPages.currentPage();
    }

    public PageReference step2() {
        if(getRecordSize()<1) return fromPage;      
        currentStep='2';         
        return ApexPages.currentPage();
    }

    public PageReference step3() {
        currentMsg = new ApexPages.Message(ApexPages.severity.INFO, getFieldInfoToDisplay());
        ApexPages.addMessage(currentMsg);
        currentStep='3';         
        return ApexPages.currentPage();
    } 

    public PageReference step4() {
        convertedFieldData = convertUserInputToFieldData();

        // data type validation
        if (currentMsg!=null) {
            ApexPages.Message msg = new ApexPages.Message(ApexPages.severity.INFO, getFieldInfoToDisplay());
            ApexPages.addMessage(msg);
            ApexPages.addMessage(currentMsg);
            return ApexPages.currentPage();
        }

        String msg = 'Please review your selections before confirm: <br></br>'; 
        msg = msg + '<br><b>Records Selected:</b>    ' + getRecordSize() +'</br>';
        msg = msg + '<br><b>Field To Be Updated:</b> ' + fieldName + '</br>';
        msg = msg + '<br><b>New Value:</b>           ' + convertedFieldData + '</br>';
        currentMsg = new ApexPages.Message(ApexPages.severity.INFO, msg);
        ApexPages.addMessage(currentMsg);
        currentStep='4';         
        return ApexPages.currentPage();
    } 

    public PageReference step5() {
        currentMsg = (new MassUpdater(objs, field, convertedFieldData)).massUpdate();
        ApexPages.addMessage(currentMsg);
        currentStep='5';         
        return ApexPages.currentPage();
    }

    public DescribeSObjectResult discoverSObjectType(SObject s) {
        Map<String, Schema.SObjectType> des = Schema.getGlobalDescribe();

        for(Schema.SObjectType o:des.values()) {
            if( s.getSObjectType()==o) {
                return o.getDescribe();
            }     
        }
        return null;
    }

    public List<SelectOption> getFieldTypeOptions() {
        // prevent url hacking
        if (objs.size()<1) return null;

        List<SelectOption> options = new List<SelectOption>();      
        options.add(new SelectOption('','-None-'));

        Schema.DescribeSObjectResult sObj = discoverSObjectType(objs.get(0));

        fieldMap = sObj.fields.getMap();

        List<String> keys = sortByFieldLabel(fieldMap);

        for(String key:keys) {
            Schema.DescribeFieldResult d = fieldMap.get(key).getDescribe();

            if(d.isAccessible() && d.isUpdateable()) {
                if (isSupportedFieldType(d)) {
                    String label = d.getLabel();
                    if(d.isCustom()) label += ' (' + key +  ')';
                    options.add(new SelectOption(key, label));
                }
            }
        }
        return options;
    }

    private List<String> sortByFieldLabel(Map<String, Schema.SObjectField> gd) {
        List<String> keys = new List<String>();

        Map<String, List<String>> labelMap = new Map<String, List<String>>();

        for(Schema.SObjectField s:gd.values()) {
            String label = s.getDescribe().getLabel();
            if(labelMap.get(label) == null) {
                labelMap.put(label, new List<String>());
            }

            labelMap.get(label).add(s.getDescribe().getName());        
        }

        List<String> labels = new List<String>(labelMap.keySet());
        labels.sort();

        for(String label:labels){
            keys.addAll(labelMap.get(label));
        }

        return keys;
    }

    public List<SelectOption> getPicklistValues() {
        return picklistValues;
    }

    private boolean isSupportedFieldType(DescribeFieldResult d) {
        // always return true for now, but in future some fields might not be supported
        return true;
    }


}

Answer 1

Schema.DescribeFieldResult has two instance methods that would accomplish what you're asking-- getName() or getLabel() -- which return the field's API name and label, respectively.

for(String key:keys) {
    Schema.DescribeFieldResult d = fieldMap.get(key).getDescribe();

    if(d.isAccessible() && d.isUpdateable() && 
       (d.getName() == fieldName1 || d.getName() == fieldName2)) {
        if (isSupportedFieldType(d)) {
            String label = d.getLabel();
            if(d.isCustom()) label += ' (' + key +  ')';
            options.add(new SelectOption(key, label));
        }
    }
}
return options;

Here is a complete list of the Schema.DescribeFieldResult instance methods: http://www.salesforce.com/us/developer/docs/apexcode/Content/apex_Schema_DescribeFieldResult_instance_methods.htm

Answer 2

What I have done in this scenario in teh past is I create field sets that I know I want to use in certain controllers and classes. Then within your method you can just go through all of the fields in your field set and add the selectoption.

This way, should you need new fields as an option, you don't have to adjust your code, you can just update the field sets. Saves some time in the future.

See below

for(Schema.FieldSetMember f : ObjectType.myObject__c.FieldSets.MyFieldSetName.getFields()) {
     options.add(new SelectOption(f.getFieldPath(), f.getFieldLabel()));
}

Answer 3

no loop simple solution as below:

Map<string, Schema.Sobjectfield> fieldMap = Schema.describeSObjects(new string[]{tobj})[0].fields.getMap(); 
//step 1: DescribeSObjectResult [] = Schema.describeSObjects(new string[]{'Account'}); 
//step 2: Map<string, Schema.Sobjectfield> fieldMap = DescribeSObjectResult[0].fields.getMap();


string theType =  fieldMap.get('Test_Number_Field__c').getDescribe().getType().name(); 
//step 1: Schema.Sobjectfield = fieldMap.get('Field Name in String'); 
step 2: Schema.DescribeFieldResult = SObjectField.getDescribe(); 
step 3:  Enum Schema.DisplayType = DescribeFieldResult.getType(); 
step 4: string s = Enum.name();