---
title: Render an SSRS report
summary: Loads, parameterizes, and renders a report from an SSRS report definition via ReportExecutionService.
status: draft
owner: SAIF Case Management
last_reviewed: 2026-08-21
library: SAIF.Services.Printing
reference_type: embedded
operation_id: OP-RSPRINT-RENDER
trigger: Caller invokes clsRSPrint.PreviewDocument
---

# Render an SSRS report

Loads a report definition from SQL Server Reporting Services, applies any configured parameters, and renders it to bytes in the selected output format.

| Field | Value |
| --- | --- |
| **Operation ID** | OP-RSPRINT-RENDER |
| **Trigger** | Caller invokes `clsRSPrint.PreviewDocument()` |
| **Inputs** | `ReportPath`, parameters added via [Add or clear SSRS report parameters](manage-ssrs-parameters.md), `Format`/`Extension` |
| **Outputs** | Rendered report bytes in the selected format |
| **Primary components** | `clsRSPrint.PreviewDocument`, `clsRSPrint.BuildParameters` |
| **Entry point** | `SAIF.Services.Printing\clsRSPrint.vb` |

## Steps

1. Sets `m_RS.Credentials = System.Net.CredentialCache.DefaultCredentials` (Windows-integrated authentication to the SSRS SOAP endpoint).*
2. Calls `m_RS.LoadReport2(ReportPath, HistoryID)` — `HistoryID` is deliberately left uninitialized/empty per an inline code comment ("don't initialize historyid — it makes the call fail with invalid SnapshotId") — loads the report definition at `ReportPath` and returns `ExecutionInfo2`.
   > **Origin**: This step is implemented in `SharepointReporting.ReportExecutionService` (`SAIF.Services.Printing.SharepointReporting`, auto-generated SOAP client proxy) and executed against the external SSRS report server.*
3. If parameters were added via [Add or clear SSRS report parameters](manage-ssrs-parameters.md), builds a `SharepointReporting.ParameterValue()` array (`BuildParameters`) from the internal `NameValueCollection` and calls `m_RS.SetExecutionParameters(...)`.
4. Calls `m_RS.Render2(m_Format, devinfo, PageCountMode.Actual, m_Extension, encoding, mimeType, Warnings, streamIDs)` to render the report in the selected `Format`/`Extension`, returning the rendered bytes.

## Process flow

```mermaid
flowchart TD
	Start([PreviewDocument called]) --> SetCreds[Set DefaultCredentials]
	SetCreds --> Load[Call LoadReport2 with ReportPath]
	Load --> HasParams{Parameters added?}
	HasParams -->|Yes| SetParams[BuildParameters and SetExecutionParameters]
	HasParams -->|No| Render
	SetParams --> Render[Call Render2]
	Render --> Return([Return rendered bytes])
```

## Failure and edge-case behavior
- SSRS executes the report's own data-source queries server-side, outside this library's visibility; no SQL/table interaction occurs in this library's own code.*
- `HistoryID` is deliberately left empty; passing a value reportedly causes the call to fail with an invalid `SnapshotId` per an inline code comment.

## Related documentation
- [Operations and processes](../operations-processes.md)
- [Business rules](../business-rules.md)

## Sources
- `SAIF.Services.Printing\clsRSPrint.vb`
- `SAIF.Services.Printing\Web References\SharepointReporting\Reference.vb`