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Share native modelling standards

Apply the same formatting and calculation structure to several models without copying the convention into each native project. Shared policy is TMDL; custom Python is not required.

Continue the native Parcel model: Delivery, Depot, the relationship and the same-name foreign-key overlay are already working. Add only the policy and format override below, keeping your workspace configuration. For direct entry, complete the native model task first; then add the policy below.

1. Add the shared policy

Create PowerBI/policy.tmdl with the native formatting and calculation policy below:

model Model
    discourageImplicitMeasures

table Delivery
    measure 'Delivery Count'
        formatString: #,##0
    measure InternalCost
        formatString: #,##0.00

table Display
    calculationGroup
        precedence: 10
        calculationItem Current = SELECTEDMEASURE()
    column Calculation
        dataType: string
        sourceColumn: Name
        summarizeBy: none
    partition Display = calculationGroup
        mode: import

The policy applies to all final models in this project and declares no physical model of its own. Here it sets two measure formats and adds a native Display calculation group with a Current calculation item. The calculation group is ordinary TMDL, including the calculationGroup partition that Power BI Desktop also writes; without it, the service adds its own partition and Build's readback check fails.

To share the foreign-key convention too, move its annotation from the local overlay into the policy’s existing model Model section. That section then reads:

model Model
    discourageImplicitMeasures
    annotation 'Weaver.AutoHideForeignKeys' = true

Keep the policy’s Delivery and Display sections below it. The next step retains that annotation locally too; once policy owns it, you can omit the duplicate local declaration.

2. Override one convention locally

Replace the earlier rule-only PowerBI/Parcel/Parcel.tmdl with the local format override below. It retains the same foreign-key declaration, so the foreign-key rule remains in effect:

model Model
    annotation 'Weaver.AutoHideForeignKeys' = true

table Delivery
    measure 'Delivery Count'
        formatString: 0 "deliveries"

The effective definition merges the native source, then shared policy, then this model's same-name overlay. The overlay's Delivery Count format wins; InternalCost retains #,##0.00. Omission is not general deletion. TMDL reference owns exact merge and replacement rules.

3. Deploy and inspect

weaver check
weaver build --item SemanticModel/Parcel

The command returned:

Terminal output exit 0
Workspace  Parcel Development
Catalogue  none
Targets
  SemanticModel/Parcel


Build

  Resolve semantic data sources                                                                            0.0s
    Resolve SemanticModel/Parcel                                                                           0.0s
  Read target inventories                                                                                  0.1s
  Read semantic sources                                                                                    0.0s
  Prepare bundle                                                                                           0.0s
Install selection
  SemanticModel/Parcel
    changed                 1
    selected for build      1

→   SemanticModel/Parcel · Deploy semantic definitions · 1 action
✓   SemanticModel/Parcel · Deploy semantic definitions · 1 action                                         21.0s
→   SemanticModel/Parcel · Verify deployed semantic definitions · 1 action
✓   SemanticModel/Parcel · Verify deployed semantic definitions · 1 action                                20.5s
  Install                                                                                                 41.5s
✓ Build                                                                                                   41.9s

Installation
    2 succeeded
    0 failed
    0 skipped
  Report  [local-path]
  Bundle  ce6f3aefefe56812fc09dd5dc15f4f40a696c13c59ca48ede27a97b34df7d447

weaver load SemanticModel/Parcel

The deployed definition now contains the Display group with its Current item, discourageImplicitMeasures, 0 "deliveries" on Delivery Count (the local override), #,##0.00 on InternalCost (the policy) and a hidden Delivery[DepotId]. The original partitions and relationship are unchanged. Delivery Count still evaluates to 2 and now formats as 2 deliveries.

Authored native files still contain the declarations, not the transformed definition. Inspect the deployed definition through the service’s Get Definition API or a native model-definition tool.

The same model can now take shared standards and a local exception. If a convention needs logic that TMDL cannot express, add a custom annotation without replacing the policy or native project.