---
title: BolPolicyHeaderViewComponent
summary: API reference for BolPolicyHeaderViewComponent.
status: draft
owner: SAIF IT Core Services
last_reviewed: 2026-10-12
library: BolMiddleware
reference_type: package
---

# BolPolicyHeaderViewComponent

View component that renders the policy header bar from a `BolPolicyModel`, or the error view when an error message is passed. It is invoked by the policy layouts.

## Purpose
- Choose between the header view and the error view ([BR-BOLMIDDLEWARE-017](../../business-rules.md#br-bolmiddleware-017-error-message-error-view)).
- Pass the policy model to the `BolPolicyHeader` default view, which shows the dropdown or label ([BR-BOLMIDDLEWARE-012](../../business-rules.md#br-bolmiddleware-012-policy-dropdown-visibility)).

## Context
- Namespace: `BolMiddleware.Components`
- Assembly/package: `BolMiddleware`

## Public members
| Member | Signature | Purpose |
| --- | --- | --- |
| `InvokeAsync` | `Task<IViewComponentResult> InvokeAsync(BolPolicyModel model, string? errorMessage)` | Returns the `Error` view with the message when one is given, otherwise the default header view with the model. |

## Behavioral notes
- Declared async but contains no await; it completes synchronously.

## Constraints and usage notes
- Invoked from layouts with the page model as argument.

## Sources
- src/BolMiddleware/ViewComponents/BolPolicyHeaderViewComponent.cs