10 AL Tips Every Business Central Developer Should Know

Writing AL for Microsoft Dynamics 365 Business Central is as much about habits as it is about syntax. Small choices—how you check for records, load fields, or pass parameters—add up across extensions, upgrades, and team handoffs.

These ten tips are practical patterns you can apply today. They focus on code quality, maintainability, and performance without adding unnecessary complexity.

Whether you are shipping your first app or refining a mature codebase, keeping these practices in mind will help you write AL that is easier to read, safer to change, and faster at runtime.

Tip 001 – Never Hardcode Configuration Values in AL Code

Never hardcode configuration values in AL code.

❌ Bad: Hardcoded values ✅ Good: Store them in a Setup table

❌ Bad

HttpClient.Get('https://api.contoso.com/orders', Response);

✅ Good

HttpClient.Get(MySetup."API Base URL", Response);

Avoid hardcoding:

• 🌐 API URLs
• 🔑 API keys
• 📧 Email addresses
• 🔒 Passwords or secrets

Why?

• ✅ Easier to maintain.
• ✅ More secure.
• ✅ No code changes required when values change.
• ✅ Different environments can have different configurations.

Rule of thumb: If a value might change, don't hardcode it—put it in a Setup table.

Tip 002 – When Checking if Records Exist, Use IsEmpty

When checking if records exist, use IsEmpty because it's faster & better for performance!

Need to check if records exist? Use IsEmpty().

✅ Good: IsEmpty() ❌ Bad: Count() > 0

❌ Bad

if SalesLine.Count() > 0 then
    Message('Sales lines exist.');

✅ Good

if not SalesLine.IsEmpty() then
    Message('Sales lines exist.');

Tip 003 – Don't Call CalcFields Inside a Loop

Don't call CalcFields inside a loop.

✅ Use CalcFields() when you need FlowFields for one record. ✅ Use SetAutoCalcFields() before FindSet() when processing multiple records.

✅ Good: SetAutoCalcFields() ❌ Bad: CalcFields() on every iteration

❌ Bad

if Item.FindSet() then
    repeat
        Item.CalcFields(Inventory);
 
        if Item.Inventory < Item."Reorder Point" then
            NotifyReorder(Item);
    until Item.Next() = 0;

✅ Good

Item.SetAutoCalcFields(Inventory);
 
if Item.FindSet() then
    repeat
        if Item.Inventory < Item."Reorder Point" then
            NotifyReorder(Item);
    until Item.Next() = 0;

• ✅ Reduces unnecessary database calls.

Tip 004 – Format Dates with FORMAT Instead of Building Strings Manually

Format dates with FORMAT instead of building strings manually.

✅ Best: Use FORMAT ❌ Avoid: Concatenating day, month, and year yourself

Why?

• ✅ Cleaner and easier to read.
• ✅ Less code and fewer opportunities for bugs.
• ✅ Supports formatting options directly.
• ✅ Easier to maintain if the format changes.

✅ Best

procedure DisplayFormattedDate()
var
    MyDate: Date;
    FormattedDate: Text;
begin
    MyDate := Today();
 
    FormattedDate := Format(MyDate, 0, '<Day,2>/<Month,2>/<Year4>');
 
    Message('%1', FormattedDate);
end;

❌ Avoid

procedure DisplayFormattedDate()
var
    MyDate: Date;
    FormattedDate: Text;
begin
    MyDate := Today();
 
    FormattedDate :=
        Format(Date2DMY(MyDate, 1)) + '/' +
        Format(Date2DMY(MyDate, 2)) + '/' +
        Format(Date2DMY(MyDate, 3));
 
    Message('%1', FormattedDate);
end;

💡 Why this matters

Imagine you later need to display:

2026-07-06

or

06 Jul 2026

With FORMAT, you simply change the format string:

Format(MyDate, 0, '<Year4>-<Month,2>-<Day,2>');

No need to rewrite the entire concatenation logic.

Tip 005 – Use TextBuilder Instead of String Concatenation

Use TextBuilder instead of string concatenation:

❌ Bad Practice: String Concatenation ✅ Good Practice: TextBuilder

Tested with 200K loops results speak for themselves!

//✅ 54 ms
procedure AppendWithTextBuilder200k()
var
    TempText: TextBuilder;
    i: Integer;
begin
    for i := 1 to 200000 do
        TempText.Append('x');
end;

//❌ 9 sec 494 ms
procedure AppendWithString200k()
var
    TempText: Text;
    i: Integer;
begin
    for i := 1 to 200000 do
        TempText += 'x';
end;

Tip 006 – Convert Simple Types to Text with ToText

Convert Simple Types to Text with ToText:

Old way (Before 2025 wave 1 (BC26) 👎)

MyText := FORMAT(MyDate);

New way (After 2025 wave 1 (BC26) 👍)

MyText := MyDate.ToText();

✅ More intuitive syntax ✅ Cleaner & more readable code

✅ Directly available on simple types (BigInteger, Boolean, Byte, Date, DateTime, Decimal, Duration, Guid, Integer, Label, Time, Version) for easy conversion to text.

Keep using FORMAT for advanced formatting, but for quick conversions, switch to ToText!

Tip 007 – Use Overloaded GetValue Methods to Retrieve JSON Values Directly

use overloaded GetValue methods to retrieve JSON values directly:

❌ Bad Practice:

if JsonObj.Get('MyNumber', JsonToken) then
    MyInteger := JsonToken.AsInteger();

✅ Good Practice:

MyInteger := JsonObj.GetInteger('MyNumber');

Tip 008 – Speed Up Record Retrieval by Only Loading Needed Fields

Speed up record retrieval by only loading needed fields:

Use Rec.SetLoadFields for Optimized Performance!

✅ Improves performance ✅ Reduces database load ✅ Loads only what's needed!

Before (Slow! 👎)

if Rec.FindSet() then
    repeat
        Message('%1', Rec.Description);
    until Rec.Next() = 0;

Now (Optimized! 👍)

Rec.SetLoadFields(Description);
if Rec.FindSet() then
    repeat
        Message('%1', Rec.Description);
    until Rec.Next() = 0;

Tip 009 – Understand var Parameters to Control Data Flow in Procedures

Understand var parameters to control data flow in procedures:

Passing parameters with var allows the procedure to modify the caller's value without var, only a copy is passed.

❌ Without var

procedure UpdateCustomerName(Customer: Record Customer)
begin
    Customer.Name := 'New Name';
end;
UpdateCustomerName(Cust);
// Cust.Name is NOT changed

✅ With var

procedure UpdateCustomerName(var Customer: Record Customer)
begin
    Customer.Name := 'New Name';
end;
UpdateCustomerName(Cust);
// Cust.Name is changed

Rule:

➡️ No var = read-only input ➡️ With var = modify the caller value

✅ Clear intent (input vs output) ✅ Avoid hidden side effects ✅ Write safer, cleaner AL code

Tip 010 – Prefer Enums over Options for Table Fields

Prefer Enums over Options for table fields

❌ Bad – Option in a table field

field(10; Status; Option)
{
    OptionMembers = Open,"In Progress",Closed;
}
UpdateStatus(1); // What does 1 mean?

✅ Better – Use an Enum

field(10; Status; Enum "Document Status")
{
}
UpdateStatus("Document Status"::"In Progress");

✅ Type-safe no magic numbers. ✅ Self-documenting code. ✅ Extensible with enumextension.

Conclusion

These ten tips are small on their own, but together they shape AL that is easier to maintain, safer to extend, and faster in production. Pick one or two to apply in your current project, then layer in the rest as you review and refactor. 🚀 Consistent habits beat one-off optimizations—and your future self (and your team) will thank you for it.