# Check-Boms

This function is executed when clicking the "Check" button within the [BOM Tab](</bom_window>).\
All the [BOMs](</code_reference/commandlets/show-bomwindow/objects/bom>) from the BOM Window can be checked against ERP.

## Syntax

```powershell
Check-Boms [-Boms] <Bom[]>
```

## Parameters

| Type                                                               | Name | Description                      | input/output | Mandatory | Default value |
|--------------------------------------------------------------------|------|----------------------------------|--------------|-----------|---------------|
| [Bom](</code_reference/commandlets/show-bomwindow/objects/bom>) \[\] | Boms | The Boms which should be checked | input        | yes       |               |


## Return type

**void**

## Remarks

Each **unique** [BOM](</code_reference/commandlets/show-bomwindow/objects/bom>) shown in the BOM Window is passed to this function.

It's recommended to update the [status](</bom_window/status>) of all the BOMs and their rows with the [](</code_reference/commandlets/show-bomwindow/commandlets/update-bomwindowentity>) cmdlet.\
Only in case of [connection problems](<erp_integrations:errors>) with [ERP cmdlets](</code_reference/commandlets/>) the status of the according BOMs and rows is automatically set to *Error*.

When an exception is thrown within this function, the BOM Window [shows the Exception](<bom_window:errors>) message of the terminated Check operation.\
The [status](</bom_window/status>) of all the [BOMs](</code_reference/commandlets/show-bomwindow/objects/bom>) and their *Children* that where not updated, gets automatically changed to *Unknown*.

## Examples

**Checking whether Vault file BOMs exist in the ERP system: BOMs are marked as "New", "Identical" and with "Error" icons:**

```powershell
function Check-Boms($boms) {
   foreach($vaultBom in $boms) {
      if($vaultBom._CategoryName -eq 'Base') {
         $vaultBom | Update-BomWindowEntity -Status 'Error' -ToolTip "BOMs for files of the category group 'Base' should not be processed"
      }

      $erpBom = Get-ERPObject -EntitySet 'Boms' -Keys @{ 'ParentNumber'= $vaultBom.Bom_Number }

      if($? -and -not $erpBom) { 
         Update-BomWindowEntity -InputObject $vaultBom -Status New -StatusDetails 'BOM does not exist in ERP'
      }
      if($erpBom) {
         Update-BomWindowEntity -InputObject $vaultBom -Status Identical -StatusDetails 'BOM exists in ERP'
      }
   }
}
```
*Note:* In case of connection problems during the *Get-ERPObject* cmdlet, the status of the currently iterated `$vaultBom` object is automatically set to *'Error'*.\
Further exception details can be retrieved via automatic variables like `$?` and `$Error[0]`.

**Checking whether the Vault file BomRows are "Identical" to those of the ERP BOMs, whether there are "New" once or rows that should be "Removed":**

```powershell
function Check-Boms($boms) {
   foreach($vaultBom in $boms) {
      $erpBom = Get-ERPObject -EntitySet 'Boms' -Keys @{ 'ParentNumber'= $vaultBom.Bom_Number } -Expand 'Children'

      #iterating ERP-BOM rows and checking if they exist in the Vault-BOM
      foreach($erpBomRow in $erpBom.Children) {
         $vaultBomRow = $vaultBom.Children | Where-Object { $_.Bom_Number -eq $erpBomRow.ChildNumber -and $_.Bom_PositionNumber -eq $erpBomRow.Position } | select -First 1
         if($vaultBomRow -eq $null) {
            $bomRow = Add-BomWindowEntity -Type BomRow -Parent $vaultBom -Properties @{
               'Bom_Number'=$erpBomRow.ChildNumber;
               'Bom_PositionNumber'=$erpBomRow.Position;
               'Bom_Quantity'=$erpBomRow.Quantity;
            }
            Update-BomWindowEntity -InputObject $bomRow -Status Remove
         }
         elseif($vaultBomRow.Bom_Quantity -cne $erpBomRow.Quantity) {
            Update-BomWindowEntity -InputObject $vaultBomRow -Status Different -StatusDetails "'Quantity' is different:`nVault '$($vaultBomRow.Bom_Quantity)'`nERP '$($erpBomRow.Quantity)'"
         }
         else {
            Update-BomWindowEntity -InputObject $vaultBomRow -Status Identical
         }
      }
      #iterating Vault-BOM rows and checking if they exist in the ERP-BOM
      if($vaultBom.Children) {
         foreach($vaultBomRow in $vaultBom.Children) {
            $erpBomRow = $erpBom.Children | Where-Object { $_.ChildNumber -eq $vaultBomRow.Bom_Number -and $_.Position -eq $vaultBomRow.Bom_PositionNumber } | select -First 1
            if( $erpBomRow -eq $null) {
               Update-BomWindowEntity -InputObject $vaultBomRow -Status New
            }
         }
      }
   }
}
```