Reboot & Resume

One of the most powerful features of PoshUI Workflows is the ability to handle system reboots and automatically resume execution.

Key Concept

RequestReboot() is not a system reboot command. It's a workflow control signal that:

1. Saves the current workflow state to disk
2. Stops the current task execution
3. Shows the user a reboot dialog
4. Allows the workflow to resume from the next task after reboot

Requesting a Reboot

From within any workflow task, call $PoshUIWorkflow.RequestReboot():

Add-UIWorkflowTask -Step 'Execution' -Name 'UpdateKernel' -Title 'Updating Kernel' -ScriptBlock {
    $PoshUIWorkflow.WriteOutput("Kernel update applied. System needs to restart.", "INFO")
    
    # Request a reboot with a reason
    $PoshUIWorkflow.RequestReboot("Kernel Update Applied")
    
    # Code after RequestReboot() will execute after resume
    $PoshUIWorkflow.WriteOutput("System rebooted successfully", "INFO")
}

What Happens

1. State Saved: Workflow state is automatically saved to %LOCALAPPDATA%\PoshUI\PoshUI_Workflow_State.json
2. Task Marked Complete: Current task is marked as completed
3. Dialog Shown: User sees reboot options ("Reboot Now", "Reboot Later", "Simulate")
4. Execution Stops: Remaining tasks pause until after reboot
5. Script Closes: The PoshUI window closes

Resuming After Reboot

When the system restarts and the user runs the script again, it automatically detects the saved state and resumes.

Basic Resume Pattern

Import-Module PoshUI.Workflow

# 1. Initialize workflow (must match the original)
New-PoshUIWorkflow -Title 'System Setup'

# 2. Check for saved state
if (Test-UIWorkflowState) {
    # 3. Load and resume from saved state
    Resume-UIWorkflow
    
    # 4. Redefine the SAME tasks (Resume-UIWorkflow marks completed ones to skip)
    Add-UIWorkflowTask -Step 'Execution' -Name 'Phase1' -Title 'Phase 1' -ScriptBlock { ... }
    Add-UIWorkflowTask -Step 'Execution' -Name 'Phase2' -Title 'Phase 2' -ScriptBlock { ... }
    
    # 5. Show the UI (skips wizard, continues from next pending task)
    Show-PoshUIWorkflow
} else {
    # First run: normal workflow setup
    Add-UIStep -Name 'Config' -Title 'Configuration' -Order 1
    Add-UITextBox -Step 'Config' -Name 'ServerName' -Label 'Server Name'
    
    Add-UIStep -Name 'Execution' -Title 'Execution' -Order 2 -Type Workflow
    Add-UIWorkflowTask -Step 'Execution' -Name 'Phase1' -Title 'Phase 1' -ScriptBlock { ... }
    Add-UIWorkflowTask -Step 'Execution' -Name 'Phase2' -Title 'Phase 2' -ScriptBlock { ... }
    
    Show-PoshUIWorkflow
}

Reboot & Resume Checklist

Use this checklist when implementing reboot/resume workflows:

• [ ] Define workflow structure - Create all steps and tasks before first run
• [ ] Call Test-UIWorkflowState - Check for saved state at script start
• [ ] Call Resume-UIWorkflow - Load saved state if it exists
• [ ] Redefine all tasks - Must define the same tasks in the same order
• [ ] Use RequestReboot() - Call from task when reboot is needed
• [ ] Test first run - Verify wizard and first tasks work
• [ ] Test resume - Simulate reboot and verify resume works
• [ ] Verify cleanup - Confirm state file is deleted after completion
• [ ] Test cancellation - Verify state file cleanup if user cancels

State File Management

Location

%LOCALAPPDATA%\PoshUI\PoshUI_Workflow_State.json

Contents

• Current task index (which task to resume from)
• All wizard input values
• Completed task output and progress
• Log file path (for continuity)
• Timestamp and computer info

Automatic Cleanup

The state file is automatically deleted when:

• Workflow completes successfully
• User cancels the workflow

Manual Cleanup

If you need to manually clear the state (for testing or recovery):

Clear-UIWorkflowState

State Persistence Details

What is Saved

• ✅ Wizard input values
• ✅ Completed task status and output
• ✅ Log file path
• ✅ Current task index

What is NOT Saved

• ❌ Variables created during task execution
• ❌ External file changes
• ❌ Registry modifications
• ❌ Installed software

Important: Your tasks should be idempotent (safe to run multiple times). For example:

• Check if software is already installed before installing
• Check if a service is already running before starting it
• Use -Force flags cautiously on resume

Example: Idempotent Task

Add-UIWorkflowTask -Step 'Execution' -Name 'InstallFeature' -Title 'Install Windows Feature' `
    -ScriptBlock {
        $feature = Get-WindowsFeature -Name 'Web-Server'
        
        if ($feature.Installed) {
            $PoshUIWorkflow.WriteOutput("Feature already installed", "INFO")
        } else {
            $PoshUIWorkflow.WriteOutput("Installing feature...", "INFO")
            Install-WindowsFeature -Name 'Web-Server'
            $PoshUIWorkflow.WriteOutput("Feature installed", "INFO")
        }
    }

Auto-Launch After Reboot (Optional)

For the best user experience, add your script to the Windows RunOnce registry key so it launches automatically after reboot:

$scriptPath = $PSCommandPath
$regPath = 'HKCU:\Software\Microsoft\Windows\CurrentVersion\RunOnce'

# Add script to RunOnce (runs once at next logon)
New-ItemProperty -Path $regPath -Name 'PoshUIWorkflow' `
    -Value "powershell.exe -NoProfile -ExecutionPolicy Bypass -File `"$scriptPath`"" `
    -Force | Out-Null

# Then request reboot
$PoshUIWorkflow.RequestReboot("System reboot required")

Troubleshooting

State file not found after reboot

• Verify the script is running as the same user
• Check that %LOCALAPPDATA% path is accessible
• Confirm Test-UIWorkflowState is called before Resume-UIWorkflow

Tasks running again after resume

• Ensure you call Resume-UIWorkflow before defining tasks
• Verify task names match exactly (case-sensitive)
• Check that task order hasn't changed

State file not deleted after completion

• Verify workflow completed without errors
• Check that all tasks have status "Completed"
• Manually clear with Clear-UIWorkflowState if needed

Next: Workflow Logging | Working with Tasks