AppSourceCop Error AS0095

The access modifier of a table field cannot be changed to a value that provides less access.

Description

The access modifier of a table field cannot be changed to a value that provides less access because it will break dependent extensions. You can only change the accessibility to provide more access.

Remarks

This rule verifies that the Access property of a field in a table or table extension has not been reduced between revisions. This rule only validates table fields if the table Access property is set to Public in the baseline extension. For more information about different access levels for both fields and tables, see Using Access Modifiers in AL.

Code examples triggering the rule

Example 1: Reducing the Access Level to lower than Public

Version 1.0 of the extension:

table 50122 MyTable
{
    Access = Public; // If omitted the default value is Public
    fields
    {
        field(1; FirstField; Code[1])
        {
            Access = Public;
        }
    }
}

Version 2.0 of the extension:

table 50122 MyTable
{
    Access = Public; // If omitted the default value is Public
    fields
    {
        field(1; FirstField; Code[1])
        {
            Access = Protected; // or Local, Internal
        }
    }
}

Reducing the Access of a field in a Table will result in breaking extensions that are already using the field.

Example 2: Reducing the Access Level to lower than Protected

Version 1.0 of the extension:

table 50122 MyTable
{
    Access = Public; // If omitted the default value is Public
    fields
    {
        field(1; FirstField; Code[1])
        {
            Access = Protected;
        }
    }
}

Version 2.0 of the extension:

table 50122 MyTable
{
    Access = Public; // If omitted the default value is Public
    fields
    {
        field(1; FirstField; Code[1])
        {
            Access = Local; // or Internal
        }
    }
}

Reducing the Access level of the field might result in breaking existing scenarios where a dependent table extension defined in other application extension references this field. This will result in compilation error AL0161. The same rule applies to fields defined in a table extension.

Example 3: Reducing the Access Level to lower than Public of a field defined in TableExtension

Version 1.0 of the extension:

tableextension 50126 MyTableExtension extends MyTable
{
    fields
    {
        field(2; OtherField; Integer)
        {
            Access = Public;
        }
    }
}

Version 2.0 of the extension:

tableextension 50126 MyTableExtension extends MyTable
{
    fields
    {
        field(2; OtherField; Integer)
        {
            Access = Protected; // or Local, Internal
        }
    }
}

Code Examples that don't trigger the rule

Example 1: Exposing the table for the first time

Version 1.0 of the extension:

table 50122 MyTable
{
    Access = Internal;
    fields
    {
        field(1; FirstField; Code[1])
        {
            Access = Public;
        }
    }
}

Version 2.0 of the extension:

table 50122 MyTable
{
    Access = Public;
    fields
    {
        field(1; FirstField; Code[1])
        {
            Access = Protected; // or any other access modifier
        }
    }
}

Changing the Access level from Internal to Public on MyTable means that we are exposing the table for first time, so we cannot reduce the access level of the field since it has already indirectly been Internal.

Example 2: Changing the Access level from Local to Internal or vice versa

Version 1.0 of the extension:

table 50122 MyTable
{
    Access = Public;
    fields
    {
        field(1; FirstField; Code[1])
        {
            Access = Local;
        }
    }
}

Version 2.0 of the extension:

table 50122 MyTable
{
    Access = Public;
    fields
    {
        field(1; FirstField; Code[1])
        {
            Access = Internal;
        }
    }
}

Changing Access level from Local to Internal or vice versa will not trigger the rule.

Example 3: Changing the Access Level to Public or Protected from lower Access Level

Version 1.0 of the extension:

table 50122 MyTable
{
    Access = Public;
    fields
    {
        field(1; FirstField; Code[1])
        {
            Access = Local; // or Internal
        }
    }
}

Version 2.0 of the extension:

table 50122 MyTable
{
    Access = Public;
    fields
    {
        field(1; FirstField; Code[1])
        {
            Access = Public; // or Protected
        }
    }
}

Example 4: Changing the Access Level to Public from Protected

Version 1.0 of the extension:

table 50122 MyTable
{
    Access = Public;
    fields
    {
        field(1; FirstField; Code[1])
        {
            Access = Protected;
        }
    }
}

Version 2.0 of the extension:

table 50122 MyTable
{
    Access = Public;
    fields
    {
        field(1; FirstField; Code[1])
        {
            Access = Public;
        }
    }
}

Example 5: Changing the Access Level to Public or Protected from a lower access level in a table extension

Version 1.0 of the extension:

tableextension 50126 MyTableExtension extends MyTable
{
    fields
    {
        field(2; OtherField; Integer)
        {
            Access = Local; // or Internal
        }
    }
}

Version 2.0 of the extension:

tableextension 50126 MyTableExtension extends MyTable
{
    fields
    {
        field(2; OtherField; Integer)
        {
            Access = Public; // or Protected
        }
    }
}

Example 6: Changing the Access Level to Public from Protected in a table extension

Version 1.0 of the extension:

tableextension 50126 MyTableExtension extends MyTable
{
    fields
    {
        field(2; OtherField; Integer)
        {
            Access = Protected;
        }
    }
}

Version 2.0 of the extension:

tableextension 50126 MyTableExtension extends MyTable
{
    fields
    {
        field(2; OtherField; Integer)
        {
            Access = Public;
        }
    }
}

Related information

AppSourceCop Analyzer
Get Started with AL
Developing Extensions