Standard APIs

With the Spring 18 release of Business Central, Microsoft introduced APIs. There 44 APIs available out-of-the-box. 

There are a lot of materials available on the web about APIs for Business Central. Some of them:

• APIs for Business Central
• How to use APIs for Business Central 

Standard APIs are perfect for Connect Apps. If you want to pull/push data to Business Central, but don’t have experience in AL or Business Central architecture – you can still build your app, using any available technology and programming language.

But what if you want to create your own APIs for Business Central?

Now, with October release, that becomes possible, and actually very easy. 

Custom APIs 

With October 18 release of Business Central now it’s possible to create your custom APIs in AL. 

Step 1. Open VS Code with AL extension installed

Usually, I use https://aka.ms/bcsandbox VM to develop in AL. But at DirectionsNA Microsoft announced support of AL for MacOS!

So, next scenario I will cover from my brand new MacOS Mojave desktop!

For Windows users … continue reading =)

Step 2. Open/clone/create AL project and download symbols

I will create a new AL project, and this will be a hybrid App. It will have Add-on capabilities (internal data structure and UI) and Connect capabilities (exposed API to my tables). 

How to create new AL project and download symbols on MacOS

Step 3. Create a new table, list page and publish an app

My app will show the list of aeroplanes. Very simple example. I will not show here, how to create new AL table and page – there are tons of material available on the web.

Here is the AL code

After this step, a user will have an opportunity to create/change/delete records in a new table from Business Central UI.

Ok, now we have Add-on app. What’s about Connected App part? 

Step 4. Create custom API for your App

Assume, that you want to provide to the world opportunity to communicate with your App. In my case, I have the list of all aeroplane’s models. So, why not to share that with the world?

Add an Id  field to the table

First, add an ID field to your table with type GUID.

Assign a value, when you insert the record

From now, any new entry in my table will have a unique ID.

API endpoints

Before continuing, let’s stop in a minute on API endpoints. Endpoint – is a URL, which gives you access to one or many entities inside of Business Central, from outside. 

You can access data, through the endpoint, using 2 types of authentication: AAD and Direct (Web service Key).

Depending on authentication type - endpoints URI will differ. In the next examples, I'll use Direct authentication.

Production Tenant

Business Central offers out-of-the box API endpoints to the base APIs. Like:

Endpoints described above, give you access to the data inside production Business Central tenant. They are well described in official docs. 

Sandbox Tenant

What about API endpoints for the online sandbox tenant? It’s not documented feature (yet). But it’s possible!

Cool, but all endpoints, described above, link us to the base 44 APIs, published by Microsoft.

Is it possible to create our own APIs? And if yes, how to call them both for production and sandbox tenants?

page 50102 "AIR AirplaneModel Entity"
{
    PageType = API;
    Caption = 'airplaneModels';
    APIPublisher = 'DmitryKatson';
    APIVersion = 'beta';
    APIGroup = 'airplanes';
    EntityName = 'airplaneModel';
    EntitySetName = 'airplaneModels';
    SourceTable = "AIR Airplane Model";
    DelayedInsert = true;
    ODataKeyFields = Id;

    layout
    {
        area(Content)
        {
            repeater(GroupName)
            {
                field(id; Id)
                {
                    Caption = 'Id';
                    ApplicationArea = All;
                }
                field(icaoCode; "ICAO Code")
                {
                    Caption = 'icaoCode';
                    ApplicationArea = All;
                }
                field(description; Description)
                {
                    Caption = 'description';
                    ApplicationArea = All;
                }

            }
        }
    }
    trigger OnInsertRecord(BelowxRec: Boolean): Boolean
    begin
        Insert(true);

        Modify(true);
        exit(false);
    end;

    trigger OnModifyRecord(): Boolean
    var
        AirplaneModel: Record "AIR Airplane Model";
    begin
        AirplaneModel.SETRANGE(Id, Id);
        AirplaneModel.FINDFIRST;

        IF "ICAO Code" <> AirplaneModel."ICAO Code" THEN BEGIN
            AirplaneModel.TRANSFERFIELDS(Rec, FALSE);
            AirplaneModel.RENAME("ICAO Code");
            TRANSFERFIELDS(AirplaneModel);
        END;
    end;
}

urlCustomApiSandbox = https://api.businesscentral.dynamics.com/v1.0/b7268087-f626-4efe-ac43-37bfaafc16d8/sandbox/api/DmitryKatson/airplanes/beta