External Objects – What Lightning Connect offers to us

On my previous post, I talked about Lightning Connect and tried to explain with the Checa Hotel example how it worked.

This post is going to explain what you can do with one of the most important elements of Lightning Connect: External Objects.

What is an External Object?

This is a new type of object that will help us to visualize the information that we have in a external repository after creating a connection between Salesforce and this repo.

As a quick reminder from the previous post. We will be able to create an External Data Source linked to the External place and we will be able to create one or many External objects from there.

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How can we define it?

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These external objects will be created:

  • Automatically: via the Validate and Sync button that we can find in the External Data Source.
  • Manually: via its entry on the menu.

But in any case my advice is to take advantage of the automatic creation and use the manual one just in case you need to modify something.

How does an External Object look like?

We are going to continue with the same example as the previous post, the Checa Hotel reservations. And this is the external object.

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At a first sight it is similar to a custom one.

External Object vs Custom Object – Differences:

  1. API Name: It ends with __x instead of __c
  2. External Data Source: This field is populated with the External Data Source from where we have created the object. This field is required if you create the object manually.
  3. Table Name: This name is automatically created when you click on Validate and Sync button and is the name of the table found in the external repository once we have created the connection. This field is required if you create the object manually.
  4. Name Field: Here we will specify the field that will help us to open every single record when we create a tab related to this object. At least I couldn’t find a way to modify the value of this field, and the default value is the External ID standard field. However I can also say that if you create the connection via a Custom Connector instead of using Heroku, for instance, this value could be a different one. But this is something we will talk about in a future blog entry.
  5. All checkboxes that you can find on below image and belongs to a Custom object, here are missed. So we can now know that Reports are not provided. That could sound disappointing to some of you, but remember that this can change in the future, and also, you can always move this external object data to a custom object and create these reports and dashboards that you need.

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External Objects Sections:

Standard Fields

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I know what you are thinking. Where are the other fields like Created By, Last Modify By etc. ? Remember that these records till Summer’15 are not writable, so we don’t really need this information. We are just showing what we have in the external repository.

Here we will only find 2 fields:

  1. External ID: This field will help us to keep the uniqueness across the whole organization. This does not mean that the ID concept that Custom Object has are not applicable here. These records will also have an ID and we will see it later, but at the same time this External Id is required.
  2. Display URL: This is a link and if you click on it, in my case where I have read the information from the Google Spreadsheet, I will have the data in XML format of the record where I clicked this field.

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So, if we click on the Display URL field, we would get this information:

<?xml version='1.0' encoding='utf-8'?>
    <entry xmlns="http://www.w3.org/2005/Atom" 
      <title type="text"/>
      <link rel="edit" title="HotelReservation" href="HotelReservation(1)"/>
      <category term="InMemoryProducerExample.HotelReservation" scheme="http://schemas.microsoft.com/ado/2007/08/dataservices/scheme"/>
      <content type="application/xml">
               <d:StartDate m:type="Edm.DateTime">2015-09-01T00:00</d:StartDate>
               <d:Price m:type="Edm.Double">125.0</d:Price>
               <d:ExternalId m:type="Edm.Int32">1</d:ExternalId>
               <d:Paid m:type="Edm.Boolean">true</d:Paid>
               <d:EndDate m:type="Edm.DateTime">2015-09-03T00:00</d:EndDate>
               <d:GuestName>Anne Kalen</d:GuestName>
               <d:RoomNumber m:type="Edm.Int32">1</d:RoomNumber>
               <d:SpecialRequirement>Balcony please</d:SpecialRequirement>

Custom Fields & Relationships

This is the section that looks like more similar to a custom object. Here we can find all the fields that the object will have. We will be able to define different types and different features. And if my Heroku application didn’t allow me to specify all that I really needed, I can make any change manually just clicking the Edit link beside the field.

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What could we miss?

We don’t see any relationship on above image, but we can really create Lookups for instance. What we would not allow to do is to create a Master-Detail relationship. But Salesforce give us a couple of workarounds to solve this situation.

  • External Lookup: This field type will help me to link 2 external objects, so if for any reason I have 2 different objects in my google spreadsheet and now I can see both in my Salesforce organization, I can link them via this field type that must be created manually because this is a Salesforce type that Java is not aware of it.
  • Indirect Lookup: This field type will help me to link an external object to a custom or standard one. Let’s talk more about this type with an example.

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Based on this image, I want to have somehow more information about my guests, in this case, Kim Rosenber. So that, I can save her information in order to send information about the hotel when we have special offers, or give her special discounts based on the number of reservations she has made with us. Because of that, I will create an Account per guest.

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Now, I would like to be able to click on my Guest Name in the HotelReservation record and go directly to the Account. Also I would like to be able to get all reservations related to each Account, so that, I can decide if this person deserves a special discount.

How can I get it? First of all we will need to create a field on Account object. The only requirement is that it should be External Id and it must be unique.

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Secondly, we need to populate it with the information of my guest. This data should be the same as I have in the external object, so this time would be the name.

Finally on the External Object we need to modify the Guest Name field type from Text to Indirect Lookup and link it to Account object. As a tip, if for any reason, you don’t create the field on Account properly, it will not appear in the drop down list and you would not have the option to link your Hotel Reservation to Account.

Captura de pantalla 2015-10-19 a las 15.25.39And how does it look like?

Guest name has a link instead of being a simple Text field

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And if we add the related list in the Account object, we can also check all reservations that this person has made

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We could think that this is similar to usual Lookup fields. The main difference is that in this case I can click on the real Guest Name and navigate to the account. However, with a Lookup, we will need to have an Id value in the External Object in order to make the navigation possible.

Page Layout

Like custom objects, this section helps us to modify the look and feel of my record, changing the way that fields are sorted, if I want to add a new section, or blank space.

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Compact Layout and Search Layout

Simple, we have the option to create new Compact Layouts and determine if I require to add any custom button in the List View.

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Buttons, Links, and Actions

We can also perform another actions with these external objects. How? For instance, creating a button with some Apex Code in the background. At the end we could work with them as they were custom or standard objects.

Now, the use case is that every time a guest leaves the hotel, we need to print the invoice in pdf format.

Let’s think that we are doing this job for a custom object. So what should we do first?

  • Create a Custom Controller
public with sharing class HotelReservationController
   public ApexPages.StandardController controller;
   public Decimal amount {get; private set;}
   public Decimal totalAmount {get; private set;}
   public HotelReservation__x reservationInfo {get; private set;}
   public HotelReservationController(ApexPages.StandardController stdController)
     controller = stdController;
     Id reservationId = controller.getRecord().Id;
     amount = calculateAmount(reservationInfo.Price__c);
     totalAmount = calculateTotalAmount(reservationInfo.Price__c);
   public void calculateReservation(Id reservationId)
     HotelReservation__x reservation = [Select EndDate__c, 
                                         From HotelReservation__x
                                         Where Id = :reservationId
                                         Limit 1];
     reservationInfo = reservation;
   public Decimal calculateAmount(Decimal amount)
     return amount.setScale(2, RoundingMode.HALF_UP);
   public Decimal calculateTotalAmount(Decimal amount)
     Decimal tax = (amount * 21) / 100;
     Decimal totalAmt = amount + tax;
     return totalAmt.setScale(2, RoundingMode.HALF_UP);

As you can see on above code, the controller is really simple. It starts getting the Id of the record so YES!! we can also use getRecord() method with External Object.

And continue doing some calculations. The most important thing is the method where we run a SOQL query. HOW?? Yes, even we don’t have any data stored in our organization, Lightning Connect will allow us to perform such actions as well as SOSL. Also I would like to highlight that even we filter by the Id that we retrieved from the Controller, we would be able to use the External ID field as this is also have a unique field value.

  • Create a Visualforce page

My Visualforce page will be a pdf with the invoice for the guest. First of all the Standard Controller will be the External Object. And secondly we will extend the functionality with the Controller that we created above. The rest, simple, just call Controller methods and fields in order to show data that we need.

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So, is it not allowed to use visualforce tags like <apex:outputField> ? Of course you can use them. Imagine you want to create a Visualforce page with some Reservation data, go for it!! it will show the name of the field as well as the type that belongs to the data. However as this is a pdf, my option was to use directly divs with all data.

  • Create a button linked to the Visualforce page that we have just created and add it to the External Object Page Layout.

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At the end, this is the result. After clicking on the Invoice Print Invoice button

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We get this pdf ready to print and share with the customer

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Field Sets

We can also create a field set related to our External Object and show it in a Visualforce page, for instance.

My field set will not provide different information from the current page layout, but this is a good example to show how Field Sets also works.

First of all we will create the Field Set

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Secondly we are going to create a Visualforce page that we will use to override View mode on this External Object.

<apex:page standardController="HotelReservation__x" extensions="HotelReservationController">
  <apex:form >
    <apex:pageBlock title="Hotel Reservation">
      <apex:pageBlockSection title="Information">
        <apex:repeat value="{!fields}" var="f">
          <apex:outputField value="{!HotelReservationFieldSet[f.fieldPath]}"/>

Similar as before we will use the HotelReservation__x as standard controller and the extension will be the same as before. This time we are going to show dynamically all fields that we have included in the FieldSet. As right now we can find all of them, this is a good page to override the view mode of any Hotel Reservation record. If in the future we need to include more fields or make some modifications, code will be exactly the same, because, as I said before, we get data dynamically.

In the controller we have just added these 2 methods and their calls in the constructor:

public List<Schema.FieldSetMember> getFields()
  return SObjectType.HotelReservation__x.FieldSets.ReservationInformation.getFields();
public HotelReservation__x calculateReservationFieldSets(Id reservationId)
  String qry = 'Select ';
  for(Schema.FieldSetMember f : getFields())
    qry += f.getFieldPath() + ', ';
  qry += 'Id, ExternalId From HotelReservation__x Where Id = :reservationId limit 1';
  return Database.query(qry);

And this is the result

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What else can I do?

If you are one of these persons that usually works with portable devices like tablets and smartphones, you don’t need to worry about this new type of objects because Salesforce1 app and Lightning Connect also allow you to see this data.




Finally I would like to highlight some limitations (based on Summer ’15 release)

  • We can only have 100 External Objects per org
  • It doesn’t allow Master-Detail relationship, but as we show above, Lightning Connect offers 2 workarounds, External Lookups and Indirect Lookups
  • We cannot create reports and dashboards with their information. If this is really required for us we can always move the data to a custom object using some apex code, and then create the report from this object.
  • Triggers are not allow. I think that the reason is that actually we are not able to control what can happens outside of Salesforce.
  • Although we can perform SOSL and SOQL, we still have some limitations, like For Update is not allow today.
  • These objects are read only. It means, we cannot edit it and see the change in my google drive, for instance. I have already realized that Winter ’16 give us this functionality, but this is something that I will talk about in a future entry after doing some more researches.

I hope this post was useful for you and understand better what you can do with these new object types and how.

Lightning Connect – Visualize your external data in Salesforce easily

By Christmas 2013, I received a fantastic present. FinancialForce.com platform team was starting to take a look at one of the new pilots that Salesforce had. By that time we called it “External Data Source” or “External Objects” however, nowadays you know it as Lightning Connect.

And here I am, writing about this feature that was released during Dreamforce ’14 and after having talked about it on such amazing event, Madrid ’15, London ’15 and finally few weeks ago at Dreamforce ’15, now, it’s time to share my knowledge via a blog entry.

So first of all, what is Lightning Connect? This feature allows you to link an external repository, Google Drive, SharePoint, Amazon and others, to your Salesforce organization, therefore, you can visualize and use the data that you have outside of your org. At this moment maybe you are thinking about an ETL (Extract – Transform – Load) but Salesforce already have features like Apex Data Loader. So keep in mind. This is not an ETL.

How does it work? The platform makes http requests to the External Repository and its information is sent back to the org in Real Time via an OData protocol.

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It could sound too technical or complicated if you are not a developer, even it could make you give up and think that Data Import Wizard will help you to solve your scenario. So let me show you a comparation of what you would need to do if you use these tools.

Data Import Wizard vs Lightning Connect

Data Import Wizard

  1. Create Custom object and / or fields
  2. Save data in a csv file
  3. Launch Import Wizard
    1. Choose the data
      1. What do I need? Create or Update
      2. Select the csv file
    2. Edit mapping
    3. Start Import

If you need to modify a record, you would have to run all sub steps that belongs to point 3.

Lightning Connect

  1. Create the connection
  2. Synchronize metadata that means create automatically the object and its fields
  3. Create a Tab
  4. Refresh the List View

Any time you need to make a modification outside of your organization, you should only need to refresh the page to see the changes in Salesforce.

Checa Hotel – Use Case

Sometimes it is easier to understand things when we see a real use case. So lets go for it.

Checa Hotel saves its reservations in a spreadsheet:

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But by the time they started moving into Salesforce, they continued using Google Drive for a while. In any case they wanted to avoid the double effort that means add reservations to the google spreadsheet and move data into Salesforce every time that a guest make a new reservation.

How can Lightning Connect help?

This Salesforce feature will help us to show in our organization any change in the Google Spreadsheet. How?

Lightning Connect is a feature that via OData protocol help us to link the external repository with your Salesforce organization. Per connection, you can create a single External Data Source that will have 1 or many External Objects. At the end this External Object is the metadata that we are going to use to show the data that is stored in the Google Spreadsheet in our case.

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What do we need to get it? We only need to follow above steps.

1. Create a Connection

1.1. Get the URL

There are different ways to get this url. At the end we need to create the connection we have explained above. And we can do it with an existing OData provider, like JitterBit, or we can create something with code. This is my case, where I have used Heroku in order to create an application in Java that is able to read a google sheet via its API.

As a start point you can check odata4j. Actually, my Java application started with some code that I pasted from this page.

So basically you only need to create your producer and register some data there. Bellow example it will just show numbers from 0 to 20.

//InMemoryProducer is a readonly odata provider that serves up POJOs 
//as entities using bean properties
//call InMemoryProducer.register to declare a new entity-set, 
//providing a entity source function and a propertyname to serve as the key
final InMemoryProducer producer = new InMemoryProducer("InMemoryProducerExample", 1000);
//expose an large list of integers as an entity-set called "Integers"
                  new Func<Iterable>()
			public Iterable apply()
                          return Enumerable.range(0, 20);
                  Funcs.method(Integer.class, Integer.class, "intValue"));

So we need to do something similar but with the data that we read from google spreadsheet.

In order to do that, the first thing is the creation of an inner class where we will store the data

public static class Reservation
   private Integer externalId;
   private Integer roomNumber;
   private Date startDate;
   private Date endDate;
   private Double price;
   private Boolean paid;
   private String guestName;
   private String specialRequirement;
   public Integer getExternalId(){ return externalId; }
   public void setExternalId(Integer value) { externalId = value; }
   //getter and setter are required to be able to read info in Salesforce

The next step is to have a method that reads the data

public static List readGoogleReservations(SpreadsheetService googleService) 
   List reservationInfo = new ArrayList();
   URL feedUrl = null;
   feedUrl = new URL("https://spreadsheets.google.com/feeds/spreadsheets/private/full");
   return reservationInfo;

And this method will be called from my producer:

	 	  new Func<Iterable>()
	 	     public Iterable apply()
	 		   return readGoogleReservations(googleServicefinal);
                        catch (Exception e) { return null; }

1.2. Create the External Data Source

Once you have your Heroku application and the url that it returns, the rest is just #clicksnotcode.

You only need to go to External Data Source entry on the left side bar menu under Setup:

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And click on New. Then just enter information about the new Connection.

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As you can see on above image, it is really simple. Just provide the Name and Type chose OData 2.0 that is the one we have used in our Heroku application.

Then, populate the Url field with the application one, that looks like


And that is all. Just save, and your connection will be created.

In the case that you are using a different way to create the connection, you would only need to select a different type from the drop down list. For instance on below image, we can also have the Salesforce option, just a Simple URL, and the Custom one that is called LoopbackDataSourceProvider. This Custom one is related to a Custom Apex Connector, another interesting topic that I will talk about in a future entry.

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2. Synchronize Metadata – Create External Object

The next step is the creation of the Metadata that will contain the information we want to show. Even we can use the External Object entry that we can find on the left side bar menu, and create it manually, my advice is to use the External Data Source and create it automatically. Just clicking on Validate and Sync button, it will read those objects that the connection provides and create them for you.

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And if we open HotelReservation one, we can check that it looks like a custom object.

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3. Create a new Tab

Finally I want to see the data in my organization, so I will just create a Tab for it and update the look and feel of the list view.

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Also, if I want to open any of the records, we will see the data as well.

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And that’s all, we have our Google Spreadsheet links to our Salesforce organization.

4. Refresh the List View

Something that I have mentioned since the very beginning is that one of the advantages of Lightning Connect is that any change outside will be reflected in Real Time in my org. And the best way to show it is with a video.


I would like to finish this entry with some bullets points that could be interesting for you

  • Limitations
    • Lightning Connect has an additional cost. How much? Please contact Salesforce.com for more information.
    • We can only have 100 external objects per org
    • It is Read Only for now, although Winter’16 brings the writable feature. Let see how it works in a future entry 🙂
    • Callouts: At the end we are making calls to google drive, so this limitation is still in place. But if you need to increase it, contact Salesforce because this is a soft limitation.
    • External Objects don’t support Master-Detail relationships but Lightning Connect offers workaround for that. Follow next entries where I will talk about what you can do with an External Object.
    • It doesn’t provide Reports for now.
  • Advantages
    • Once you have the Url, the configuration is #clicksnotcode
    • It provides to end user Real Time refresh so if you are worried about performance, just keep in mind that the first time you open your External Object tab, it will take a bit longer because it is doing the connection. But from that moment, any update will be as fast as your internet connection allows you.
    • Finally, something that can make you think that pay for it, worth it. It doesn’t count against the storage limitation because we are not saving anything in Salesforce. We are just showing what we have outside. It is like a mirror.

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I hope now you can understand a bit better Lightning Connect and all its benefits.

Enjoy and see you in my next entry.