handle bit sets in apex
Thu Nov 03 2022 12:05:58 GMT+0000 (Coordinated Universal Time)
Map<String,List<String>> pickValueMap=DependentPickListValueController.GetDependentOptions('SObject','ControllingPickList','DependentPicklist');
/////////////////////////////////////////////////////////////////////////////////////////////////
public class DependentPickListValueController{
public DependentPickListValueController(){}
public static Map<String,List<String>> GetDependentOptions(String pObjName, String pControllingFieldName, String pDependentFieldName){
Map<String,List<String>> objResults = new Map<String,List<String>>();
//get the string to sobject global map
Map<String,Schema.SObjectType> objGlobalMap = Schema.getGlobalDescribe();
//get the type being dealt with
Schema.SObjectType pType = objGlobalMap.get(pObjName);
Map<String, Schema.SObjectField> objFieldMap = pType.getDescribe().fields.getMap();
//get the control values
List<Schema.PicklistEntry> ctrl_ple = objFieldMap.get(pControllingFieldName).getDescribe().getPicklistValues();
//get the dependent values
List<Schema.PicklistEntry> dep_ple = objFieldMap.get(pDependentFieldName).getDescribe().getPicklistValues();
//iterate through the values and get the ones valid for the controlling field name
PickListUtils.Bitset objBitSet = new PickListUtils.Bitset();
//set up the results
for(Integer pControllingIndex=0; pControllingIndex<ctrl_ple.size(); pControllingIndex++){
//get the pointer to the entry
Schema.PicklistEntry ctrl_entry = ctrl_ple[pControllingIndex];
//get the label
String pControllingLabel = ctrl_entry.getLabel();
//create the entry with the label
objResults.put(pControllingLabel,new List<String>());
}
//check the dependent values
for(Integer pDependentIndex=0; pDependentIndex<dep_ple.size(); pDependentIndex++){
//get the pointer to the dependent index
Schema.PicklistEntry dep_entry = dep_ple[pDependentIndex];
//get the valid for
String pEntryStructure = JSON.serialize(dep_entry);
PickListUtils.PicklistDetails objDepPLE = (PickListUtils.PicklistDetails)JSON.deserialize(pEntryStructure, PickListUtils.PicklistDetails.class);
//iterate through the controlling values
for(Integer pControllingIndex=0; pControllingIndex<ctrl_ple.size(); pControllingIndex++){
if (objBitSet.fitBit(objDepPLE.validFor,pControllingIndex)){
//get the label
String pControllingLabel = ctrl_ple[pControllingIndex].getLabel();
objResults.get(pControllingLabel).add(objDepPLE.label);
}
}
}
return objResults;
}
}
//////////////////////////////////////////////////////////////////
public class PickListUtils{
public PickListUtils(){}
public class PicklistDetails{
public string active {get;set;}
public string defaultValue {get;set;}
public string label {get;set;}
public string value {get;set;}
public string validFor {get;set;}
public PicklistDetails(){}
}
public class Bitset{
public Map<String,Integer> AlphaNumCharCodes {get;set;}
public Map<String, Integer> Base64CharCodes { get; set; }
public Bitset(){
findChacterCodes();
}
private void findChacterCodes(){
AlphaNumCharCodes = new Map<String,Integer>{
'A'=>65,'B'=>66,'C'=>67,'D'=>68,'E'=>69,'F'=>70,'G'=>71,'H'=>72,'I'=>73,'J'=>74,
'K'=>75,'L'=>76,'M'=>77,'N'=>78,'O'=>79,'P'=>80,'Q'=>81,'R'=>82,'S'=>83,'T'=>84,
'U'=>85,'V'=> 86,'W'=>87,'X'=>88,'Y'=>89,'Z'=>90
};
Base64CharCodes = new Map<String, Integer>();
//lower case
Set<String> pUpperCase = AlphaNumCharCodes.keySet();
for(String pKey : pUpperCase){
//the difference between upper case and lower case is 32
AlphaNumCharCodes.put(pKey.toLowerCase(),AlphaNumCharCodes.get(pKey)+32);
//Base 64 alpha starts from 0 (The ascii charcodes started from 65)
Base64CharCodes.put(pKey,AlphaNumCharCodes.get(pKey) - 65);
Base64CharCodes.put(pKey.toLowerCase(),AlphaNumCharCodes.get(pKey) - (65) + 26);
}
//numerics
for (Integer i=0; i<=9; i++){
AlphaNumCharCodes.put(string.valueOf(i),i+48);
//base 64 numeric starts from 52
Base64CharCodes.put(string.valueOf(i), i + 52);
}
}
public Boolean fitBit(String pValidFor,Integer n){
//the list of bytes
List<Integer> pBytes = new List<Integer>();
//multiply by 6 since base 64 uses 6 bits
Integer bytesBeingUsed = (pValidFor.length() * 6)/8;
//will be used to hold the full decimal value
Integer pFullValue = 0;
//must be more than 1 byte
if (bytesBeingUsed <= 1)
return false;
//calculate the target bit for comparison
Integer bit = 7 - (Math.mod(n,8));
//calculate the octet that has in the target bit
Integer targetOctet = (bytesBeingUsed - 1) - (n >> bytesBeingUsed);
//the number of bits to shift by until we find the bit to compare for true or false
Integer shiftBits = (targetOctet * 8) + bit;
//get the base64bytes
for(Integer i=0;i<pValidFor.length();i++){
//get current character value
pBytes.Add((Base64CharCodes.get((pValidFor.Substring(i, i+1)))));
}
//calculate the full decimal value
for (Integer i = 0; i < pBytes.size(); i++){
Integer pShiftAmount = (pBytes.size()-(i+1))*6;//used to shift by a factor 6 bits to get the value
pFullValue = pFullValue + (pBytes[i] << (pShiftAmount));
}
//shift to the bit which will dictate true or false
Integer tBitVal = ((Integer)(Math.Pow(2, shiftBits)) & pFullValue) >> shiftBits;
return tBitVal == 1;
}
}
}
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