Differences in the development environments

Coming from the Dynamics NAV development environment and C/SIDE, it's good to know about some differences and optimizations between them. The following sections go through some of these changes, but it isn't an exhaustive list.

Tip

A very useful tool working in Visual Studio Code is IntelliSense, which gives you a list of options in the current context. To activate IntelliSense from anywhere in the code, select Ctrl+Space.

General development approach

While you could change the existing Dynamics NAV source code using C/SIDE, the best approach to develop with the AL Language development environment is to work with Extensions only. It means that you can extend the existing code by adding new functionality or integrate your code using Events. But, it isn't possible to change the existing code, for example in codeunits.

With Business Central 2019 release wave 2, the possibility to change or "code-customize" the base application was introduced for on-premise installations. But, it was also announced that in the future, code-customization won't be an option, only extension model will be used.

Data types

C/SIDE	AL Language Development Environment
Dates are parsed based on culture settings.	Locale independent and supports only: yyyy-mm-ddD.
Boolean values are expressed as yes/no.	Boolean values are expressed as true/false.
For tables, integers can allow decimal values. For example, 5.0 converts to an integer, 5.4 throws an error at runtime.	For tables, Min, Max, InitValue numbers with a fraction are expressed as decimal, thus they aren't a valid integer data type.
The largest constant integer can be 999999999999999.	Transforms to 999'999'999'999'999.0, a decimal value. In AL, this can be expressed as 999999999999999.0 or 999999999999999L.

Syntax updates

C/SIDE	AL Language Development Environment
The token for multilanguage comment is @@@.	A multilanguage comment is marked with Comment.

Several properties are renamed, for example:

C/SIDE	AL Language Development Environment
AutoFormatExpr	AutoFormatExpression
DataCaptionExpr	DataCaptionExpression
Layout	GridLayout
ProviderID	Provider

Note

Property values are considered syntax elements; thus they must follow the standard AL escaping rules.

Multilanguage properties

With the introduction of .xliff files, the ML properties, such as CaptionML and TooltipML aren't used for this translation method. Use the equivalent properties instead, such as Caption and Tooltip. Then, make sure the manifest is set up to generate the /Translations folder and use the generated .xliff files for translations of the extension. For more information, see Working with Translation Files.

Pages

The ActionContainer elements in AL have been renamed; the following table lists the renamed elements:

C/SIDE	AL Language Development Environment
ActionItems	Processing
ActivityButtons	Sections
HomeItems	Embedding
NewDocumentItems	Creation
RelatedInformation	Navigation
Reports	Reporting

For instance, area(Sections) can be defined inside the actions section of the page.

Likewise, Container and ContainerType elements in C/SIDE are renamed to area(Content|FactBoxes|RoleCenter) and can be defined inside the layout section of the page.

Note

For backward compatibility, we continue to support adding non-part pages as parts. It's a good idea to redesign your page to only use Card part or List part, as we may remove support in a future update.

For syntax examples, see Page Object and Page Extension Object.

Naming

Controls, actions, and methods names must be unique on pages. In C/SIDE, you could create a Part control with the same name as a method, which would give you an error at runtime. It's now prevented by disallowing duplicates. Similarly, trigger and trigger event names are disallowed on matching application object types. Likewise, actions and fields could have same names before, but that would have prevented page testability access, and will now throw a compilation error.

Note

Name on Controls and Actions on Pages is mandatory now.

Property dependencies

For some properties to work, they require you to set another property. An example is PromotedCategory, which requires that you've enabled the property Promoted. The following table lists some of the properties that have this dependency.

Property	Depends on the property...
PromotedCategory	Promoted
PromotedIsBig	Promoted
ValidateTableRelation	TableRelation
SourceTableTemporary	SourceTable
RunPageMode	RunObject

Limited functionality

The InitValue property of type Duration isn't allowed in the AL Language development environment. The InitValue of type DateTime is only allowed for the value 0DT.

See Also

Developing Extensions
Get Started with AL
AL Development Environment