Jeff Douglas - Technology, Coding and Bears... OH MY! » Apex

Video – Debugging Apex Tools and Techniques (DF11)

Jeff Douglas — Mon, 24 Oct 2011 12:00:43 +0000

The new System Log (aka Apex CSI) is a cool new part of Winter 12 that significantly reduces the pain of debugging Force.com applications. This is a great video from Dreamforce 11 showing you how to use the new console to debug code, set “breakpoints” and examine heap variables and more.

www.youtube.com/watch?v=Hl2cY7eW2Ko

Salesforce Trigger when Rollups Summaries Not Possible

Jeff Douglas — Tue, 23 Aug 2011 11:15:31 +0000

Master-Details relationships in Force.com are very handy but don’t fit every scenario. For instance, it’s not possible to implement a rollup summary on formula field or text fields. Here’s a small trigger that you can use for a starter for these types of situations. The code for each class is available at GitHub for your forking pleasure.

So here’s the (not very useful) use case. Sales Order is the Master object which can have multiple Sales Order Items (detail object). The Sales Order Item has a “primary” Boolean field and a “purchased country” field. Each time Sales Order Items are inserted or updated, if the Sales Order Item is marked as “primary” then the value of “purchased country” is written into the “primary country” field on the Sales Order. I’m assuming that there can only be one Sales Order Item per Sales Order that is marked as primary. Essentially this is just a quick reference on the Sales Order to see which country is primary on any of the multiple Sales Order Items. Not very useful but illustrative.

The code is broken down into a Trigger and an Apex “handler” class that implements the actual functionality. It’s best practice to only have one trigger for each object and to avoid complex logic in triggers. To simplify testing and resuse, triggers should delegate to Apex classes which contain the actual execution logic. See Mike Leach’s excellent trigger template for more info.

SalesOrderItemTrigger (source on GitHub) - Implements trigger functionality for Sales Order Items. Delegates responsibility to SalesOrderItemTriggerHandler.

trigger SalesOrderItemTrigger on Sales_Order_Item__c (after insert, after update) {
 
  SalesOrderItemTriggerHandler handler = new SalesOrderItemTriggerHandler();
 
  if(Trigger.isInsert && Trigger.isAfter) {
    handler.OnAfterInsert(Trigger.new);
 
  } else if(Trigger.isUpdate && Trigger.isAfter) { 
    handler.OnAfterUpdate(Trigger.old, Trigger.new, Trigger.oldMap, Trigger.newMap);
 
  }
 
}

SalesOrderItemTriggerHandler (source on GitHub) - Implements the functionality for the sales order item trigger after insert and after update. Looks at each sales order item and if it is marked as primary_item__c then moves the primary_country__c value from the sales order item to the associated sales order’s primary_country__c field.

public with sharing class SalesOrderItemTriggerHandler {
 
  // update the primary country when new records are inserted from trigger
  public void OnAfterInsert(List newRecords){
    updatePrimaryCountry(newRecords); 
  }
 
  // update the primary country when records are updated from trigger  
  public void OnAfterUpdate(List oldRecords, 
      List updatedRecords,  Map oldMap, 
      Map newMap){
    updatePrimaryCountry(updatedRecords); 
  }
 
  // updates the sales order with the primary purchased country for the item
  private void updatePrimaryCountry(List newRecords) {
 
    // create a new map to hold the sales order id / country values
    Map salesOrderCountryMap = new Map();
 
    // if an item is marked as primary, add the purchased country
    // to the map where the sales order id is the key 
    for (Sales_Order_Item__c soi : newRecords) {
      if (soi.Primary_Item__c)
        salesOrderCountryMap.put(soi.Sales_Order__c,soi.Purchased_Country__c);
    } 
 
    // query for the sale orders in the context to update
    List orders = [select id, Primary_Country__c from Sales_Order__c 
      where id IN :salesOrderCountryMap.keyset()];
 
    // add the primary country to the sales order. find it in the map
    // using the sales order's id as the key
    for (Sales_Order__c so : orders)
      so.Primary_Country__c = salesOrderCountryMap.get(so.id);
 
    // commit the records 
    update orders;
 
  }
 
}

Test_SalesOrderItemTriggerHandler (source on GitHub) - Test class for SalesOrderItemTrigger and SalesOrderItemTriggerHandler. Achieves 100% code coverage.

@isTest
private class Test_SalesOrderItemTriggerHandler {
 
  private static Sales_Order__c so1;
  private static Sales_Order__c so2;
 
  // set up our data for each test method
  static {
 
  	Contact c = new Contact(firstname='test',lastname='test',email='no@email.com');
  	insert c;
 
    so1 = new Sales_Order__c(name='test1',Delivery_Name__c=c.id);
    so2 = new Sales_Order__c(name='test2',Delivery_Name__c=c.id);
 
    insert new List{so1,so2};
 
  }
 
  static testMethod void testNewRecords() {
 
    Sales_Order_Item__c soi1 = new Sales_Order_Item__c();
    soi1.Sales_Order__c = so1.id;
    soi1.Quantity__c = 1;
    soi1.Description__c = 'test';
    soi1.Purchased_Country__c = 'Germany';
 
    Sales_Order_Item__c soi2 = new Sales_Order_Item__c();
    soi2.Sales_Order__c = so1.id;
    soi2.Quantity__c = 1;
    soi2.Description__c = 'test';
    soi2.Purchased_Country__c = 'France';
    soi2.Primary_Item__c = true;
 
    Sales_Order_Item__c soi3 = new Sales_Order_Item__c();
    soi3.Sales_Order__c = so2.id;
    soi3.Quantity__c = 1;
    soi3.Description__c = 'test';
    soi3.Purchased_Country__c = 'Germany';
    soi3.Primary_Item__c = true;
 
    Sales_Order_Item__c soi4 = new Sales_Order_Item__c();
    soi4.Sales_Order__c = so2.id;
    soi4.Quantity__c = 1;
    soi4.Description__c = 'test';
    soi4.Purchased_Country__c = 'Germany';
 
    Sales_Order_Item__c soi5 = new Sales_Order_Item__c();
    soi5.Sales_Order__c = so2.id;
    soi5.Quantity__c = 1;
    soi5.Description__c = 'test';
    soi5.Purchased_Country__c = 'Italy';
 
    insert new List{soi1,soi2,soi3,soi4,soi5}; 
 
    System.assertEquals(2,[select count() from Sales_Order_Item__c where Sales_Order__c = :so1.id]);
    System.assertEquals(3,[select count() from Sales_Order_Item__c where Sales_Order__c = :so2.id]); 
 
    System.assertEquals('France',[select primary_country__c from Sales_Order__c where id = :so1.id].primary_country__c);
    System.assertEquals('Germany',[select primary_country__c from Sales_Order__c where id = :so2.id].primary_country__c);
 
  }
 
  static testMethod void testUpdatedRecords() {
 
    Sales_Order_Item__c soi1 = new Sales_Order_Item__c();
    soi1.Sales_Order__c = so1.id;
    soi1.Quantity__c = 1;
    soi1.Description__c = 'test';
    soi1.Purchased_Country__c = 'Germany';
 
    Sales_Order_Item__c soi2 = new Sales_Order_Item__c();
    soi2.Sales_Order__c = so1.id;
    soi2.Quantity__c = 1;
    soi2.Description__c = 'test';
    soi2.Purchased_Country__c = 'France';
    soi2.Primary_Item__c = true;
 
    insert new List{soi1,soi2}; 
 
    // assert that the country = France
    System.assertEquals('France',[select primary_country__c from Sales_Order__c where id = :so1.id].primary_country__c);
 
    List items = [select id, purchased_country__c from Sales_Order_Item__c 
      where Sales_Order__c = :so1.id and primary_item__c = true];
    // change the primary country on the sales order item. should trigger update
    items.get(0).purchased_country__c = 'Denmark';
 
    update items;
    // assert that the country was successfully changed to Denmark
    System.assertEquals('Denmark',[select primary_country__c from Sales_Order__c where id = :so1.id].primary_country__c);
 
  }
 
}

Roll Your Own Salesforce “Lookup” Popup Window

Jeff Douglas — Fri, 12 Aug 2011 12:18:48 +0000

Let’s talk about the standard salesforce.com “lookup” popup window for a few minutes. You know what I’m talking about.. this button right here

It’s a handy little button that pops up whenever you need to search for related records. It does a pretty good job but it has some serious drawbacks:

It’s virtually impossible to modify your search criteria. What if you want your users to do some crazy search based upon custom logic or search a field that is not typically available? Sorry… you are out of luck. Not possible.
It’s terrible for creating new records. Let’s say that a user searches for a specific related record and it (absolutely) doesn’t exist. To create the new record they need to close the lookup window, navigate to the tab to create the new related record, create the new record, then go back to the original record they were either editing or creating, pop up the lookup window again and find their newly created record. Wow! That’s a lot of work.
“Quick Create” is evil! You can enable the “Quick Create” option for an entire org but don’t do it! It displays, by default, on the tab home pages for leads, accounts, contacts, forecasts, and opportunities! The major problems are that you can only create new records for these 5 objects (what about the other ones!?), you can’t customize the fields on the page and validation rules don’t fire (can you say, “bad data”).

Here’s the Solution!

I have some good news and some bad news. For standard page layouts I can’t help you. Go vote for this idea and this idea. However, for Visualforce page I have a solution to all of these problems with code!

Here’s how it looks. It may be easier to watch it full screen at YouTube.

www.youtube.com/watch?v=CGeFt6hdgRY

Here’s the code you need to accomplish this. You need two Visualforce pages (the record you are editing and the popup window) and two Apex controllers (a simple one for the record you are editing and the controller for the search and new record popup).

MyCustomLookupController - code at github

Here’s the Apex controller for the record you are either creating or editing. This is an extremely simple controller that just creates a new contact so you can use the lookup for the related account field.

public with sharing class MyCustomLookupController {
 
  public Contact contact {get;set;}
 
  public MyCustomLookupController() {
    contact = new Contact();
  }
 
}

MyCustomLookup - code at github

This is the “magical” Visualforce page that uses jQuery to intercept the popup and instead of showing the standard salesforce.com pop, shows our custom popup instead. The user experience is seamless.

CustomAccountLookupController - code at github

The Apex controller for the custom popup window is yours to customize. I know what you are thinking, “Free at last! Free at last! Thank God Almighty, we are free at last!” This class has all of your custom search functionality plus the method to create a new account. This is demo code so the search is very limited and does not prevent soql injections.

public with sharing class CustomAccountLookupController {
 
  public Account account {get;set;} // new account to create
  public List results{get;set;} // search results
  public string searchString{get;set;} // search keyword
 
  public CustomAccountLookupController() {
    account = new Account();
    // get the current search string
    searchString = System.currentPageReference().getParameters().get('lksrch');
    runSearch();  
  }
 
  // performs the keyword search
  public PageReference search() {
    runSearch();
    return null;
  }
 
  // prepare the query and issue the search command
  private void runSearch() {
    // TODO prepare query string for complex serarches & prevent injections
    results = performSearch(searchString);               
  } 
 
  // run the search and return the records found. 
  private List performSearch(string searchString) {
 
    String soql = 'select id, name from account';
    if(searchString != '' && searchString != null)
      soql = soql +  ' where name LIKE \'%' + searchString +'%\'';
    soql = soql + ' limit 25';
    System.debug(soql);
    return database.query(soql); 
 
  }
 
  // save the new account record
  public PageReference saveAccount() {
    insert account;
    // reset the account
    account = new Account();
    return null;
  }
 
  // used by the visualforce page to send the link to the right dom element
  public string getFormTag() {
    return System.currentPageReference().getParameters().get('frm');
  }
 
  // used by the visualforce page to send the link to the right dom element for the text box
  public string getTextBox() {
    return System.currentPageReference().getParameters().get('txt');
  }
 
}

CustomAccountLookup - code at github

Any finally the Visualforce page for the popup itself. It contains a tabbed interface easily allowing a user to search for records and create new ones. Make sure you look at the code for the second tab for creating a new record. I have better things to do than change the fields on the input form every time a new field is created or something is made required. The solution is to use field sets! So when an administrator makes a change, they can simply update the field set and the popup reflects the change accordingly. Life is good.

OpportunityAccessLevel Not Writable

Jeff Douglas — Thu, 17 Mar 2011 10:40:44 +0000

I was working on a project the other day where I needed to dynamically add users to an opportunity’s Sales Team (OpportunityTeamMember object) so that users who do not normally have access to an opportunity based upon Org-wide security settings can work on the opportunity with other team members. One of the advantages of Sales Teams is that you can specify the level of access that each team member has for the opportunity. Some team members may need read/write access while others may just need read-only access.

From the opportunity page layout you can add a new team member and specify their access level and role.

However, by default when you create a new team member via Apex, the platform grants them read-only access. So I tried to specify grant “Edit” (read/write) access with the following code.

OpportunityTeamMember member = new OpportunityTeamMember();
member.OpportunityId = SomeOpp.Id;
member.UserId = SomeUser.Id;
mmember.TeamMemberRole = 'Sales Rep';
member.OpportunityAccessLevel = 'Edit';

Specifying the OpportunityAccessLevel threw the following error when saving my class:

Save error: Field is not writable: OpportunityTeamMember.OpportunityAccessLevel

To be fair, the docs state that OpportunityAccessLevel is not creatable but it used to be with earlier versions of the API so I really wanted this to work and it was screwing up my day.

So here’s the solution that I can up with in case anyone is looking for a answers. You need to add the team members to the opportunity and then update the sharing access to the opportunity for these users.

OpportunityTeamMember member = new OpportunityTeamMember();
member.OpportunityId = SomeOpp.Id;
member.UserId = SomeUser.Id;
mmember.TeamMemberRole = 'Sales Rep';
 
insert member;
 
// get all of the team members' sharing records
List shares = [select Id, OpportunityAccessLevel, 
  RowCause from OpportunityShare where OpportunityId IN :SomeSetOfOpptyIds 
  and RowCause = 'Team'];
 
// set all team members access to read/write
for (OpportunityShare share : shares) 
  share.OpportunityAccessLevel = 'Edit';
 
update shares;

Dynamically Group & Display Query Results

Jeff Douglas — Wed, 02 Mar 2011 10:55:14 +0000

I was working on a Visualforce page that displays the results of a query in separate PageBlock sections based upon a value in the query results. I ran into a small issue which took about an hour or so to solve, so I thought it might make descent blog fodder.

The requirement for the page was to query for records and then display them grouped in sections in a Visualforce page based upon whatever values (in this case BillingState) are returned in the results. If additional states were added, then the Visualforce page should be able to add those new sections without changes to the code. Here’s a screenshot of the sample solution that I came up with but you can also run this sample on my Developer Site:

Here’s the code for the Visualforce page. I’ve made it as bare as possible but you can see that it iterates over the array of states to display the pageBlock sections and then displays the record if the state matches the current blockSection’s state.


  
 
  
 
    
 
       
 
        
        {!account.Name} - {!account.BillingState}

The Controller exposes two collections to the Visualforce page: the list of Accounts and the array of States. Here’s the issue that I ran into. Since I wanted to have a collection of unique state names, I originally added each state to a Set and simply returned the Set to the Visualforce page (instead of the array) to display the pageBlock sections. However, returning the Set gave me a compile error at line 11 in the Visualforce page:

Save error: Incorrect parameter for operator ‘=’. Expected Text, received Object

The problem is that even though the Set is a collection of Strings, it is actually an object underneath the covers and throws a comparison error. Therefore you have to return the states as an array of strings for the code to compile and run properly.

public with sharing class DisplaySectionsController {
 
  public List accounts {get;set;}  
  public String[] states {get;set;}
 
  public void load() {
 
    // for demo purposes limit the states  
    accounts = [Select ID, Name, BillingState From Account 
      Where BillingState IN ('CA','NY','FL')];
 
    // dynamically create set of unique states from query
    Set stateSet = new Set();
    for (Account a : accounts)
      stateSet.add(a.BillingState);
 
    // convert the set into a string array  
    states = new String[stateSet.size()];
    Integer i = 0;
    for (String state : stateSet) { 
      states[i] = state;
      i++;
    }
 
  }
 
}

Fun with Salesforce Collections

Jeff Douglas — Thu, 06 Jan 2011 15:51:08 +0000

The Apex language provides developers with three classes (Set, List and Map) that make it easier to handle collections of objects. In a sense these collections work somewhat like arrays, except their size can change dynamically, and they have more advanced behaviors and easier access methods than arrays. If you are familiar with the Java Collections API then these should feel very warm and cozy. Each collection has characteristics that make it applicable in certain situations and we’ll cover these in detail. We’ll talk about each of the collections, their features, how they are typically used and show some sample code that you can execute in your org.

Note: Salesforce.com recently made an important change to collections. There is no longer a limit on the number of items a collection can hold. However, there is a general limit on heap size.

I tried to fit virtually everything that I could about collections onto a single blog post hoping it will make good Evernote fodder. If I left something out, please drop a comment below.

Set

A set is a collection of unique, unordered elements. It can contain primitive data types (String, Integer, Date, etc) or sObjects. If you need ordered elements use a List instead. You typically see Sets used to store collections of IDs that you want to use in a SOQL query.

The basic syntax for creating a new Set is:

Set set_name
[= new Set();] |
[= new Set{value [, value2. . .] };] |;

Examples:

Set s = new Set();
Set s = new Set{‘Jon’, ‘Quinton’, ‘Reid’};

As mentioned before one of the main characteristics of a Set is the uniqueness of elements. You can safely try to add the same element (e.g., 100, ‘c’, 125.25) to a Set more than once and it will just disregard the duplicate (without throwing an Exception). However, there is a slight twist when dealing with sObjects. Uniqueness of sObjects is determined by comparing fields in the objects. The following code will result in only one element in the Set.

Account acct1 = new account(Name=’ACME Corp’);
Account acct2 = new account(Name=’ACME Corp’);
Set s = new Set{acct1, acct2}; // Set will only contain 1 element

Different field values cause the objects to become unique.

Account acct1 = new account(Name=’ACME Corp’, BillingAddress=’100 Main’);
Account acct2 = new account(Name=’ACME Corp’);
Set s = new Set{acct1, acct2}; // Set will only contain 2 elements

Set Methods
There are a number Set methods so check out the docs for a complete list, but here are some of the more common ones you might use. You can paste the following snippet of code into your browser’s System Log and run it anonymously.

// create a new set with 3 elements
Set s = new Set{'Jon', 'Quinton', 'Reid'};
// adds an element IF not already present
s.add('Sandeep');
// adds an element IF not already present
s.add('Sandeep'); 
// return the number of elements
System.debug('=== number of elements: ' + s.size()); 
// removes the element if present
s.remove('Reid'); 
 // return the number of elements
System.debug('=== number of elements: ' + s.size());
// returns true if the set contains the specified element
System.debug('=== set contains element Jon: ' + s.contains('Jon')); 
// output all elements in the set
for (String str : s) 
  // outputs an element
  System.debug('=== element : ' + str); 
// makes a duplicate of the set
Set s1 = s.clone(); 
// displays the contents of the set
System.debug('=== contents of s1: ' + s1); 
// removes all elements
s1.clear(); 
// returns true if the set has zero elements
System.debug('=== is the s1 set empty? ' + s1.isEmpty());

You should see the following (abbreviated) output:

DEBUG|=== number of elements: 4
DEBUG|=== number of elements: 3
DEBUG|=== set contains element Jon: true
DEBUG|=== element : Jon
DEBUG|=== element : Quinton
DEBUG|=== element : Sandeep
DEBUG|=== contents of s1: {Jon, Quinton, Sandeep}
DEBUG|=== is the s1 set empty? true

Commonly you’ll see developers construct a Set of IDs from a query, trigger context, etc. and then use it as part of the WHERE clause in their SOQL query:

Set ids = new Set{’0017000000cBlbwAAC’,’0017000000cBXCWAA4′};
List accounts = [Select Name From Account Where Id = :ids];

List

Lists are the mostly widely used collection so learn to love them (I do!!). A List is a collection of primitives, user-defined objects, sObjects, Apex objects or other collections (can be multidimensional up to 5 levels). Use a List (as opposed to a Set) when the sequence of elements is important. You can also have duplicate elements in a List. List are zero-based so the first element in the List is always 0.

The basic syntax for creating a new List is:

List list_name
[= new List();] |
[=new List{value [, value2. . .]};] |;

Examples:

List s = new List();
List s = new List{‘Jon’, ‘Quinton’, ‘Reid’};

// Create a nested List of Sets
List>> s2 = new List>>();

// Create a List of contact records from a SOQL query
List contacts = [SELECT Id, FirstName, LastName FROM Contact LIMIT 10];

Lists and Arrays are pretty much interchangeable and you can mix and match them:

List contacts = newContact[] {new(), newContact()};

List s = new List{'Jon', 'Quinton', 'Reid'};
String[] s1 = new String[]{'Jon', 'Quinton', 'Reid'};
System.debug('=== ' + s.get(0));
System.debug('=== ' + s1.get(0));
System.debug('=== ' + s[0]);
System.debug('=== ' + s1[0]);

You should see the following (abbreviated) output:

DEBUG|=== Jon
DEBUG|=== Jon
DEBUG|=== Jon
DEBUG|=== Jon

List Methods
There are a number List methods so check out the docs for a complete list, but here are some of the more common ones you might use. You can paste the following snippet of code into your browser’s System Log and run it anonymously.

List s = new List{'Jon', 'Quinton', 'Reid'};
// adds an element
s.add('Sandeep'); 
// adds an element
s.add('Sandeep'); 
// return the number of elements
System.debug('=== number of elements: ' + s.size());
// displays the first element 
System.debug('=== first element: ' + s.get(0)); 
// removes the first element
s.remove(0); 
// return the number of elements
System.debug('=== number of elements: ' + s.size()); 
// makes a duplicate of the set
List s1 = s.clone(); 
// displays the contents of the set
System.debug('=== contents of s1: ' + s1); 
// replace the last instance of 'Sandeep' with 'Pat'
s1.set(3,'Pat'); // displays the contents of the set
System.debug('=== contents of s1: ' + s1); 
// sorts the items in ascending (primitave only)
s1.sort(); 
// displays the contents of the set
System.debug('=== sorted contents of s1: ' + s1); 
// removes all elements
s.clear(); 
// returns true if the set has zero elements
System.debug('=== is the list empty? ' + s.isEmpty());

You should see the following (abbreviated) output:

You can use a List of Strings in the same sort of way you would a Set as part of a SOQL query:

List ids = new List{’0017000000cBlbwAAC’,’0017000000cBXCWAA4′};
List accounts = [Select Name From Account Where Id IN :ids];

Since SOQL queries return Lists of records, you can use them directly for iteration:

for (Account a : [Select Id, Name From Account Limit 2]) {
System.debug(‘=== ‘ + a.Name);
}

You can also use the List in a traditional for loop:

List accounts = [Select Id, Name From Account Limit 2];
for (Integer i=0;i System.debug(‘=== ‘ + accounts.get(i).Name);
}

Map

A Map is a collection of key-value pairs. Keys can be any primitive data type while values can include primitives, Apex objects, sObjects and other collections. Use a map when you want to quickly find something by a key. Each key must be unique but you can have duplicate values in your Map.

The basic syntax for creating a new Map is:

Map map_name
   [=new map();] |
   [=new map
   {key1_value => value1_value
   [, key2_value => value2_value. . .]};] |;

Examples:

Map m = new Map{5 => ‘Jon’, 6 => ‘Quinton’, 1 => ‘Reid’};
Map> m = new Map>();
// creates a map where the key is the ID of the record
Map aMap = new Map([Select Id, Name From Account LIMIT 2]);

Map Methods
There are a number Map methods so check out the docs for a complete list, but here are some of the more common ones you might use. You can paste the following snippet of code into your browser’s System Log and run it anonymously.

Map m = new Map{5 => 'Jon', 6 => 'Quinton', 1 => 'Reid'};
// displays all keys
System.debug('=== all keys in the map: ' + m.keySet()); 
// displays all values
System.debug('=== all values in the map (as a List): ' + m.values()); 
// does the key exist?
System.debug('=== does key 6 exist?: ' + m.containsKey(6)); 
// fetches the value for the key
System.debug('=== value for key 6: ' + m.get(6)); 
// adds a new key/value pair
m.put(3,'Dave'); 
// returns the number of elements
System.debug('=== size after adding Dave: ' + m.size()); 
// removes an element
m.remove(5); 
System.debug('=== size after removing Jon: ' + m.size());
// clones the map
Map m1 = m.clone(); 
System.debug('=== cloned m1: ' + m1);
// removes all elements
m.clear(); 
// returns true if zero elements
System.debug('=== is m empty? ' + m.isEmpty());

You should see the following (abbreviated) output:

DEBUG|=== all keys in the map: {1, 5, 6}
DEBUG|=== all values in the map (as a List): (Reid, Jon, Quinton)
DEBUG|=== does key 6 exist?: true
DEBUG|=== value for key 6: Quinton
DEBUG|=== size after adding Dave: 4
DEBUG|=== size after removing Jon: 3
DEBUG|=== cloned m1: {1=Reid, 3=Dave, 6=Quinton}
DEBUG|=== is m empty? true

Maps are used very frequently to store records that you want to process or as containers for “lookup” data. It’s very common to query for records and store them in a Map so that you can “do something” with them. The query below creates a Map for you where the key is the ID of the record. This makes it easy to find the record in the Map based upon the ID. You can paste the following snippet of code into your browser’s System Log and run it anonymously.

Map accountMap = new Map(
  [Select Id, Name From Account LIMIT 2]);
System.debug('=== ' + accountMap);
// keySet() returns a Set we can iterate through
for (Id id : accountMap.keySet()) {
  System.debug('=== ' + accountMap.get(id).Name);
}

You’ll use Maps quite a bit when writing triggers. For before update and after update triggers there are two trigger context variables named oldMap and newMap. The oldMap contains a list of sObject before they were modified. The newMap contains a list of sObject with the updated values. You typically use these Maps to make some sort of comparison inside the trigger:

for (Id id : Trigger.newMap.keySet()) {
  if (Trigger.oldMap.get(id).LastName != Trigger.newMap.get(id).LastName) {
    System.debug(‘=== the last name has changed!!’);
    // handle the name change somehow
  }
}

Maps are also used extensively to stay within governors and limits. The following is code from Writing Bulk Triggers in Salesforce.com:

trigger AddOwnerColor on Account (before insert, before update) {
 
  // create a set of all the unique ownerIds
  Set ownerIds = new Set();
  for (Account a : Trigger.new)
      ownerIds.add(a.OwnerId);  
 
  // query for all the User records for the unique userIds in the records
  // create a map for a lookup / hash table for the user info
  Map owners = new Map([Select Favorite_Color__c from User Where Id in :ownerIds]); 
 
  // iterate over the list of records being processed in the trigger and
  // set the color before being inserted or updated
  for (Account a : Trigger.new)
      a.Owner_Favorite_Color__c = owners.get(a.OwnerId).Favorite_Color__c;
 
}

Modifying Collection Elements
Modifying a collection’s elements while iterating through that collection is not supported and will throw an error. To add or remove elements for a collection, while iterating over the collection, create a new temporary list with these elements. Then simply add or remove them after you are finished iterating the collection.

Custom Iterators
Apex has the ability to create custom Iterators but that is a little beyond the scope of this post.

Force.com Programming Best Practices

Jeff Douglas — Thu, 21 Oct 2010 11:56:18 +0000

Wes and I are adding a few more topics to our Salesforce Handbook before we put it to bed and I thought a great topic would be programming best practices. I’ve never seen a “complete” list of best practices so I thought I would put something together based upon my experiences. I know I’ve left some out, so if you have any to add, please chime in and we may include them in the book.

Apex

Since Apex is case insensitive you can write it however you’d like. However, to increase readability, follow Java capitalization standards and use two spaces instead of tabs for indentation.
Use Asychronous Apex (@future annotation) for logic that does not need to be executed synchronous.
Asychronous Apex should be “bulkified”.
Apex code must provide proper exception handling.
Prevent SOQL and SOSL injection attacks by using static queries, binding variables or the escapeSingleQuotes method.
When querying large data sets, use a SOQL “for” loop
Use SOSL over SOQL where possible – it’s much faster.
Use Apex Limits Methods to avoid hitting governor exceptions.
No SOQL or SOSL queries inside loops
No DML statements inside loops
No Async (@future) methods inside loops
Do not use hardcoded IDs

Triggers

There should only be one trigger for each object.
Avoid complex logic in triggers. To simplify testing and resuse, triggers should delegate to Apex classes which contain the actual execution logic. See Mike Leach’s excellent trigger template for more info.
Bulkify any “helper” classes and/or methods.
Trigers should be “bulkified” and be able to process up to 200 records for each call.
Execute DML statements using collections instead of individual records per DML statement.
Use Collections in SOQL “WHERE” clauses to retrieve all records back in single query
Use a consistent naming convention including the object name (e.g., AccountTrigger)

Visualforce

Do not hardcode picklists in Visualforce pages; include them in the controller instead.
Javascript and CSS should be included as Static Resources allowing the browser to cache them.
Reference CSS at the top and JavaScript a the bottom of Visualforce pages as this provides for faster page loads.
Mark controller variables as “transient” if they are not needed between server calls. This will make your page load faster as it reduces the size of the View State.
Use to iterate over large collections.
Use the cache attribute with the component to take advantage CDN caching when appropriate

Unit Testing

Use a consistent naming convention including “Test” and the name of the class being tested (e.g., Test_AccountTrigger)
Test classes should use the @isTest annotation
Test methods should craete all data needed for the method and not rely on data currently in the Org.
Use System.assert liberally to prove that code behaves as expected.
Test each branch of conditional logic
Write test methods that both pass and fail for certain conditions and test for boundary conditions.
Test triggers to process 200 records – make sure your code is “bulkified” for 200 records and doesn’t throw the dreaded “Too many SOQL queries: 21″ exception.
When testing for governor limits, use Test.startTest and Test.stopTest and the Limit class instead of hard-coding governor limits.
Use System.runAs() to execute code as a specific user to test for sharing rules (but not CRUD or FLS permissions)
Execute tests with the Force.com IDE and not the salesforce.com UI. We’ve seen misleading code coverage results when running from the salesforce.com UI.
Run the Force.com Security Source Scanner to test your Org for a number of security and code quality issues (e.g., Cross Site Scripting, Access Control Issues, Frame Spoofing)

Error – Portal account owner must have a role??

Jeff Douglas — Thu, 02 Sep 2010 14:05:08 +0000

I wrote the following test class for a PRM deployment and received this crazy error when running the test:

System.DmlException: Insert failed. First exception on row 0; first error: UNKNOWN_EXCEPTION, portal account owner must have a role: []

I searched the message boards but couldn’t find any reference to the real culprit. My original thought was that the user being created was causing an error somehow. However, the real problem was that my user was not assigned a role. Hopefully this post saves someone some time tracking down the solution.

  Account a = new Account(Name='Test Account Name');
  insert a;
 
  Contact c = new Contact(LastName = 'Contact Last Name', AccountId = a.id);
  insert c;
 
  User user = new User();
  user.ProfileID = [Select Id From Profile Where Name='Some Profile'].id;
  user.EmailEncodingKey = 'ISO-8859-1';
  user.LanguageLocaleKey = 'en_US';
  user.TimeZoneSidKey = 'America/New_York';
  user.LocaleSidKey = 'en_US';
  user.FirstName = 'first';
  user.LastName = 'last';
  user.Username = 'test@appirio.com';   
  user.CommunityNickname = 'testUser123';
  user.Alias = 't1';
  user.Email = 'no@email.com';
  user.IsActive = true;
  user.ContactId = c.Id;
 
  insert user;
 
  System.RunAs(user) {
    // do all of my tests
  }

You will also see this same error (for the same reason) when trying to enable a contact as a partner or customer portal user.

Managing the Heap in Salesforce.com

Jeff Douglas — Mon, 16 Aug 2010 11:42:50 +0000

With the Spring ’10 release, Salesforce.com removed the limit on the number of items a collection can hold. So now, instead of ensuring that your collections contain no more than 1000 items, you have to monitor your heap size. Here are some strategies on how to write Apex scripts that run within these limits.

First of all, what is the heap? Dynamic memory allocation (also known as heap-based memory allocation) is the allocation of memory storage for use in a computer program during the runtime of that program. In Apex the heap is the reference to the amount of memory used by your reachable objects for a given script and request. When you create objects in your Apex code, memory is allocated to store these objects.

As with many other things in Force.com, there are governors and limits that prevent you from hijacking the heap and degrading the performance of other running applications. The heap limit is calculated at runtime and differs on how your code is invoked:

Triggers – 300,000 bytes
Anonymous Blocks, Visualforce Controllers, or WSDL Methods – 3,000,000 bytes
Tests – 1,500,000 bytes

These limits also scale with trigger batch sizes:

For 1-40 records, the normal limits apply
For 41-80 records, two times the normal limits apply
For 81-120 records, three times the normal limits apply
For 121-160 records, four times the normal limits apply
For 161 or more records, five times the normal limits apply

Luckily Salesforce.com increased the heap size limits in Summer ’10 but you still may run into some issues. Here are a few things you can do to write heap-friendly code.

Watch the Heap

When your scripts run you can view the heap size in the debug logs. If you notice your heap approaching the limit, you will need to investigate why and try to refactor your code accordingly.

Use the Transient Keyword

Try using the “Transient” keyword with variables in your controllers and extensions. The transient keyword is used to declare instance variables that cannot be saved, and shouldn’t be transmitted as part of the view state for a Visualforce page.

Use Limit Methods

Use heap limits methods in your Apex code to monitor/manage the heap during execution.

Limits.getHeapSize() – Returns the approximate amount of memory (in bytes) that has been used for the heap in the current context.
Limits.getLimitHeapSize() – Returns the total amount of memory (in bytes) that can be used for the heap in the current context.

// check the heap size at runtime
if (Limits.getHeapSize > 275000) {
// implement logic to reduce
}

One strategy to reduce heap size during runtime is to remove items from the collection as you iterate over it.

Put Your Objects on a Diet

If the objects in your collection contain related objects (i.e., Account objects with a number of related Contacts for each) make sure the related objects only contain the fields that are actually needed by your script.

Use SOQL For Loops

SOQL “for” loops differ from standard SOQL statements because of the method they use to retrieve sObjects. To avoid heap size limits, developers should always use a SOQL “for” loop to process query results that return many records. SOQL “for” loops retrieve all sObjects in a query and process multiple batches of records through the use of internal calls to query and queryMore.

for (List contacts : [select id, firstname, lastname 
  from contact where billingState = 'NY']) {
 
  // implement your code to modify records in this batch
 
  // commit this batch of 200 records
  update contacts;
}

Note: There used to be a strategy for dealing with heap intensive scripts by moving them asynchronous, @Future methods. However, since the heap limits were increased in Summer ’10 this is no longer a reason to simply use @Future method as the limits are the same.

Any other ideas on how to effectively manage the heap?

Using the Salesforce.com OAuth Playground

Jeff Douglas — Wed, 28 Jul 2010 12:39:25 +0000

My article on developer.force.com, Using OAuth to Authorize External Applications, shows how to develop external Java applications that use OAuth to access your Saleforce.com data. But what if you want to do the opposite? What if you need to write an application on the Force.com platform that uses your data from Google, Twitter, LinkedIn or TripIt using OAuth? Luckily Jesper Jorgenson at Salesforce.com posted an open source project called sfdc-oauth-playground which is a generic consumer implementation of OAuth as a Force.com App.

The main purpose of this beta project is to show you how to write OAuth signed requests in Apex. There is a managed packaged you can install into your org but if you really want to dig into the guts of OAuth (and who doesn’t??) you’ll need to download and install the source code from the project. The managed package doesn’t afford you to opportunity to modify code or view granular debug statements.

Jesper doesn’t provide much documentation for the project so I’ve put together a short video showing how to get started using Google Accounts and Blogger. Unfortunately different providers implement OAuth to their own liking so you sometimes have to make modifications to the requests being sent over the wire. I ran into a number of issues so hopefully this will assist you in getting up and running with OAuth.

www.youtube.com/watch?v=sXJxG6zWSZA

In case you don’t have time for the video, here are a couple of screenshots outlining the process using the OAuth Consumer Playground application from the managed package.

Create a new OAuth Service (e.g., Blogger) with various URLs for accessing services

Authorize Salesforce access to Blogger

Grant access to Blogger

Authorization confirmation

OAuth Service access tokens

Testing the service