Ekom.Printer 1.3.1

Ekom.Printer

Ekom.Printer automatically prints picking slips on a warehouse printer. The website captures the order and prepares an HTML slip; the Windows agent sends it to the selected printer.

You can print when an order reaches a selected status, or request a picking slip from your own code at the point you choose. Each station uses one of these modes. You can also customize the slip's content and layout.

Set up the website

Install the package in your website project:

dotnet add package Ekom.Printer

Explicit capture requires Ekom.Printer 1.1.0 or later. Use the matching Ekom web-assets release for your Umbraco version to display the Printing tab in Ekom Manager. Windows Agent 1.0.0 supports both trigger modes.

In Program.cs, register printing after Ekom's services and map its endpoints after building the application:

using Ekom.Printer;
using Ekom.Printer.Api;

builder.Services.AddEkomPrinter(builder.Configuration);

var app = builder.Build();
app.MapEkomPrinter();

Keep your existing application setup and middleware. The default picking-slip template works without registering a custom renderer.

Configure appsettings.json

This example enables printing on order-status changes, using the default StatusChange trigger mode:

{
  "Ekom": {
    "Printing": {
      "Enabled": true,
      "HtmlRetentionDays": 30,
      "HistoryRetentionDays": 90,
      "OfflineAfterSeconds": 120,
      "ClaimTimeoutSeconds": 300,
      "Stations": [
        {
          "Alias": "main-warehouse",
          "TokenSha256": "REPLACE_WITH_64_CHARACTER_SHA256_HASH",
          "StoreAliases": [ "main" ],
          "PickingSlip": {
            "Enabled": true,
            "TriggerMode": "StatusChange",
            "TriggerStatuses": [ "OfflinePayment", "ReadyForDispatch" ],
            "PrintPolicy": "OncePerOrder",
            "Copies": 1
          }
        }
      ]
    }
  }
}

This station prints when an order reaches OfflinePayment or ReadyForDispatch. With OncePerOrder, reaching both statuses still creates only one slip.

To control when a picking slip is requested from your own code, use ExplicitCapture. Replace PickingSlip with:

"PickingSlip": {
  "Enabled": true,
  "TriggerMode": "ExplicitCapture",
  "TriggerStatuses": [],
  "PrintPolicy": "OncePerOrder",
  "Copies": 1
}

In this mode, your code calls IPickingSlipCapture when the order is ready to print, for example after warehouse processing or a custom approval step. Save the order data you want on the slip before making the call. Order-status changes do not create slips. See Control printing from your code for the API call, retry behavior and switching existing stations safely.

Choose one mode per station. StatusChange remains the default when TriggerMode is omitted. ExplicitCapture requires an empty TriggerStatuses list and OncePerOrder.

Replace main with your store alias and main-warehouse with the station name you will enter in the Windows agent. Generate a token using the instructions below and replace REPLACE_WITH_64_CHARACTER_SHA256_HASH with its hash.

Restart the website after changing configuration. Printing is disabled unless Ekom:Printing:Enabled is true. All instances of the website must use the same settings.

In status-change mode, OncePerOrder prints once across the selected statuses; OncePerStatus allows one slip for each selected status. Repeated notifications do not create extra jobs. Existing orders are not printed automatically when you enable the feature; a subsequent qualifying status change is needed. New orders created in a selected status are eligible too.

Create a station token and TokenSha256

Generate one random token per station, then hash the exact token text with SHA-256. You can generate it on your Mac even though the agent runs on Windows.

macOS Terminal

Open Terminal and run:

token="$(openssl rand -base64 32)"
hash="$(printf '%s' "$token" | shasum -a 256 | awk '{print $1}')"

printf 'Agent station credential: %s\n' "$token"
printf 'Website TokenSha256:     %s\n' "$hash"

Use printf '%s' as shown: it hashes the token without adding a newline.

Windows PowerShell

Works with Windows PowerShell 5.1 and PowerShell 7:

$bytes = New-Object byte[] 32
$rng = [Security.Cryptography.RandomNumberGenerator]::Create()
$rng.GetBytes($bytes)
$rng.Dispose()

$token = [Convert]::ToBase64String($bytes)
$sha = [Security.Cryptography.SHA256]::Create()
$hash = $sha.ComputeHash([Text.Encoding]::UTF8.GetBytes($token))
$sha.Dispose()
$tokenSha256 = ([BitConverter]::ToString($hash)).Replace('-', '').ToLowerInvariant()

Write-Host "Agent station credential: $token"
Write-Host "Website TokenSha256:     $tokenSha256"

Where to put each value

Keep the original token in a password manager and share it securely with the person setting up the agent. These commands display it in your terminal. The hash cannot be used to recover the token.

To rotate a credential, generate a new token, replace the website hash and the agent's saved credential, restart the website, and test the connection again.

Connect the Windows agent

Install the Windows Printer Agent on the warehouse computer. The printer driver must already be installed.

1. Open Ekom Printer Agent Setup as administrator.
2. Enter the website's HTTPS URL, the matching station alias and the original token.
3. Select the printer and save with automatic printing paused.
4. Run Test connection, then Test print, and check the printed page.
5. Enable automatic printing and save again.

The test page uses the Windows service account, whose printer access can differ from the logged-in user's. See the agent setup guide for installation, upgrades and connection troubleshooting.

Control printing from your code

Use ExplicitCapture to decide when to request a picking slip from your own code. Order-status changes do not create slips for that station. AddEkomPrinter registers IPickingSlipCapture for dependency injection:

using Ekom.Models;
using Ekom.Printer.Services;

public sealed class WarehousePrinting(IPickingSlipCapture capture)
{
    public Task<PickingSlipCaptureResult> CaptureSavedOrderAsync(
        OrderData savedOrder, CancellationToken cancellationToken = default)
        => capture.CaptureAsync(savedOrder, "main-warehouse", cancellationToken);
}

Call it after saving and committing the warehouse metadata, before marking your integration's dispatch work complete. Pass the saved OrderData, including its updated OrderInfo JSON. Values stored elsewhere must first be copied into the saved order, for example into CustomData.

A successful call means the order has been saved for printing. It does not mean the slip has finished rendering or physically printed. The result contains JobId and Created; Created is false when a capture or job already exists for that order, store and station.

Keep dispatch work available for retry until capture succeeds. If capture fails, retry it. If capture succeeds but completing dispatch work fails, retry with the same order and station. These retries do not create another slip. The first saved snapshot is kept, so retrying does not replace it with newer metadata.

Capture fails if printing is disabled, the station uses status-change mode, or the order's store is not assigned to that station. Database errors and cancellation also reach the caller; do not mark dispatch complete after a failed capture.

Switching an existing station

Pause the integration, set TriggerMode to ExplicitCapture, clear TriggerStatuses, and use OncePerOrder. Review existing captures and jobs before resuming: changing settings does not cancel work already queued.

An earlier OncePerOrder slip prevents a new capture for the same order and station, and its metadata is not replaced. Earlier OncePerStatus slips can still print alongside an explicit capture. Resolve those orders before switching. Use the Manager's review and reprint actions when another copy is needed.

Customize the picking slip

Implement IPickingSlipHtmlRenderer to return a complete HTML document, then register it after AddEkomPrinter:

using Ekom.Printer.Rendering;

builder.Services.AddScoped<IPickingSlipHtmlRenderer, MyPickingSlipRenderer>();

Use print CSS for page size, margins and page breaks. Embed images and fonts in the HTML using data URIs. Encode customer-provided text with HtmlEncoder.Default.Encode. The agent blocks JavaScript, external network requests and local-file access.

To include addresses, shelf locations or warehouse references, implement IPickingSlipContextFactory and register it in the same way:

builder.Services.AddScoped<IPickingSlipContextFactory, MyPickingSlipContextFactory>();

The factory receives the saved order snapshot. Copy custom values into PickingSlipContext.Data or a line's Data dictionary, then read them in the renderer. Do not fetch the latest order while rendering: the slip should reflect the data captured when printing was requested.

Factories and renderers run in the background and may run again after a restart. Keep them free of side effects such as updating orders or sending messages. Factory failures are retried; rendering failures appear in the Manager for review and retry.

Manage printing in Ekom Manager

The Printing tab shows jobs, previews, history and station connections. You can filter by order, station or status. Users see only the stores they are allowed to access. Change station settings in appsettings and select the physical printer in the Windows agent.

Administrators can retry failed slip generation, cancel jobs that have not been claimed, and reprint slips while their stored HTML is available. To grant these actions to other backoffice groups, add their aliases to Ekom:Printing:ManagerGroups.

Submitted to printer means the Windows print queue accepted the job. It does not confirm that paper was printed. Online means the agent contacted the website recently; it does not confirm that the printer has paper or is working.

For Needs review jobs, check the physical output and the Windows queue before choosing:

• Mark as printed: record that you confirmed the output, without printing again.
• Print again after checking: close the uncertain job and queue a replacement using its saved HTML and copy count. Clear any pending original from the Windows queue first.

Uncertain jobs are not automatically printed again. Review and reprint actions record who performed them and when. A normal reprint uses the saved slip, not newer order data.

Storage and retention

The package creates and updates its own tables in the Ekom database when the website starts with printing enabled. No manual table creation is needed. Disabling or removing the package does not delete those tables.

HtmlRetentionDays controls how long completed slips and their snapshots remain available. HistoryRetentionDays controls how long their identifying history is kept and must be at least as long as HTML retention. These periods start when a job completes or is cancelled. After the HTML expires, preview and reprint are unavailable.

Queued, failed and unresolved work is retained for recovery. A minimal record remains after history cleanup to prevent an old order from printing again.

Troubleshooting

• The agent cannot connect: check the HTTPS URL, station alias and original token. Make sure printing is enabled and app.MapEkomPrinter() is registered. The agent's Test connection message explains common configuration and network errors.
• No slip appears in explicit mode: confirm your integration calls CaptureAsync after saving warehouse data. Changing order status alone does not trigger this mode.
• No slip appears in status-change mode: check the station's store and trigger statuses. Direct SQL updates bypass Ekom's status handling.
• A slip has old warehouse data: the first captured snapshot is preserved. Check whether an earlier status trigger captured the order before your warehouse work finished.
• Printer tables are missing: upgrade to the current package, enable printing and restart the website. Check startup logs and database permissions if creation fails. Do not drop printer tables or manually change migration records to force a retry.

For custom agent integrations, see the printer agent protocol reference.