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Last modified: Mar 19, 2024

PDF

How to configure the generation of PDF

New PDF generation

Enable feature

As of version 7.5 of the nuget packages (Altinn.App.Api and Altinn.App.Core) a new way of generating PDFs launched as a preview. This feature can be toggled on/off by adding the following section and feature toggle in appsettings.json.

  "FeatureManagement": {
    "NewPdfGeneration": true
  }

This will call the new PDF service which accepts a URL pointing back to an automatic generated page in the app. The rendered page is then used as the foundation for the PDF. The IPdfFormatter as documented below is still relevant if you need custom logic for excluding components/pages from PDF.

Settings

While the default settings for the new service should be enough for most applications they can be overridden by adding a PdfGeneratorSettings section in appsettings.json (default settings shown below).

  "PdfGeneratorSettings": {
    "ServiceEndpointUri": "https://{org}.apps.{hostName}/{appId}/#/instance/{instanceId}",
    "AppPdfPageUriTemplate": "https://{org}.apps.{hostName}/{appId}/#/instance/{instanceId}?pdf=1",
    "WaitForSelector": "#readyForPrint",
    "WaitForTime": 5000
  }

If the WaitForSelector is set, the WaitForTime will be ignored. The WaitForSelector ensures that the page will be completely rendered before the PDF is generated.

There are two different methods of configuring the generation of PDFs:

  1. Automatically based on your form layouts
  2. Manually by defining a custom PDF layout (v7.5+ only)

It is also possible to get a preview of what the PDF will look like in the browser while developing (v7.5+ only).

Automatic configuration

This method is used by default unless you specify a custom PDF layout file. This method extracts all of your pages and components in the order they appear, and displays them in the PDF document.

Excluding pages and components

Often, you will need to exclude certain pages or components that are not relevant to the PDF document. This is can be configured in two different ways:

  1. By modifying the Settings.json file for your layout set.
  2. Programmatically by implementing it in code. This allows for dynamic exclusion depending on the form data.

Depending on the version you are using, the programmatic method is set up differently, but the logic is the same. See below how to set this up for the version you are on:

    1. Create a class that implements the IPdfFormatter interface found in the Altinn.App.Core.Features.Pdf namespace.
      You can name and place the file in any folder you like within your project, but we suggest you use meaningful namespaces like in any other .Net project.
    2. Register you custom implementation in the Program.cs class.
      services.AddTransient<IPdfFormatter, PdfFormatter>();
      
      This ensures your custom code is known to the application and that it will be executed.
    Modify the PdfHandler.cs file under App/logic/Print.

    1. Settings.json

    Add a list of page names to exclude called excludeFromPdf under pages:

    {
       "$schema": "https://altinncdn.no/toolkits/altinn-app-frontend/4/schemas/json/layout/layoutSettings.schema.v1.json",
       "pages": {
          "order": ["page1", "page2"],
          "excludeFromPdf": ["page2"]
       }
    }
    

    2. Programmatically

    public async Task<LayoutSettings> FormatPdf(LayoutSettings layoutSettings, object data)
    {
      if (data.GetType() == typeof(Skjema))
      {
        layoutSettings.Pages.ExcludeFromPdf.Add("page2");
      }
      return await Task.FromResult(layoutSettings);
    }
    

    Note: You only need to choose one of the above methods.

    1. Settings.json

    Add a list of component IDs to exclude called excludeFromPdf under components:

    {
       "$schema": "https://altinncdn.no/toolkits/altinn-app-frontend/4/schemas/json/layout/layoutSettings.schema.v1.json",
       "pages": {
          "order": ["page1"]
       },
       "components": {
          "excludeFromPdf": ["image-component-id"]
       }
    }
    

    2. Programmatically

    public async Task<LayoutSettings> FormatPdf(LayoutSettings layoutSettings, object data)
    {
      if (data.GetType() == typeof(Skjema))
      {
        layoutSettings.Components.ExcludeFromPdf.Add("image-component-id");
      }
      return await Task.FromResult(layoutSettings);
    }
    

    Note: You only need to choose one of the above methods.

    If you need to exclude one or more components from a specific entry in a repeating group, this is done by specifying the index of the group element in addition to the component ID.

    The required format is: componentId-<groupIndex>.

    1. Settings.json

    {
       "$schema": "https://altinncdn.no/toolkits/altinn-app-frontend/4/schemas/json/layout/layoutSettings.schema.v1.json",
       "pages": {
          "order": ["page1"]
       },
       "components": {
          "excludeFromPdf": ["ownerId-1"]
       }
    }
    

    2. Programmatically

    public async Task<LayoutSettings> FormatPdf(LayoutSettings layoutSettings, object data)
    {
      if (data.GetType() == typeof(Skjema))
      {
        layoutSettings.Components.ExcludeFromPdf.Add("ownerId-1");
      }
      return await Task.FromResult(layoutSettings);
    }
    

    Note: You only need to choose one of the above methods.

    Custom layout configuration

    This method is only available in version 7.5 and higher.

    This method lets you fully customize the generated PDF by using a layout file to specify what it should contain.

    To use this method you need to create a new layout file for the PDF and set pdfLayoutName in Settings.json to point to that file:

    {
       "$schema": "https://altinncdn.no/toolkits/altinn-app-frontend/4/schemas/json/layout/layoutSettings.schema.v1.json",
       "pages": {
          "order": ["page1"],
          "pdfLayoutName": "myPdfLayout"
       }
    }
    

    This layout file is configured in exactly the same way as any other layout file, except that not all component types are allowed. The component types that can be used for a PDF layout file are the following:

    • Summary
    • Group
    • InstanceInformation
    • Header
    • Paragraph
    • Image
    • Panel

    The automatic layout includes a front page with instance information like sender, receiver, date sent, and reference number. This information should also be included in your custom layout. The example below shows how to include this information in exactly same way as in the automatic method:

    {
       "$schema": "https://altinncdn.no/toolkits/altinn-app-frontend/4/schemas/json/layout/layout.schema.v1.json",
       "data": {
          "layout": [
             {
                "id": "pdf-instance",
                "type": "InstanceInformation",
                "elements": {
                   "dateSent": true,
                   "sender": true,
                   "receiver": true,
                   "referenceNumber": true
                },
                "pageBreak": {
                   "breakAfter": "always"
                }
             },
             ...
          ]
       }
    }
    

    You can specify that a component should start on a new page or that a page break should occur immediately following a component using the pageBreak property. This property can be applied to any component. In the example below it is applied to a header to have a different section start on a new page:

    {
       "$schema": "https://altinncdn.no/toolkits/altinn-app-frontend/4/schemas/json/layout/layout.schema.v1.json",
       "data": {
          "layout": [
             {
                "id": "pdf-header",
                "type": "Header",
                "textResourceBindings": {
                   "title": "This is a new section"
                },
                "size": "L",
                "pageBreak": {
                   "breakBefore": "always",
                   "breakAfter": "avoid"
                }
             }
          ]
       }
    }
    

    Note: The value of breakBefore and breakAfter can either be auto (default), always, avoid, or an expression returning any of these values.

    It is possible to exclude child components from a group by using the excludedChildren property on a Summary component pointing to a Group component. This is done by adding the child component ID to the list of excluded components like in the following example:

    {
       "$schema": "https://altinncdn.no/toolkits/altinn-app-frontend/4/schemas/json/layout/layout.schema.v1.json",
       "data": {
          "layout": [
             {
                "id": "pdf-group-summary",
                "type": "Summary",
                "componentRef": "some-group-component",
                "excludedChildren": [
                   "some-child-component"
                ]
             }
          ]
       }
    }
    

    Preview in the browser

    This preview is only applicable to the new PDF generation method (v7.5+). See above for more information.

    It is possible to get a preview of what the generated PDF will look like in the browser while you are developing. Follow the instructions below:

    1. Important: Use Google Chrome to preview the PDF.
      The PDF generator uses a version of Chrome to generate the PDF, and other browsers will not produce the correct result.
    2. Start your app locally or open your app in the test environment, and start an instance.
    3. Open the developer tools by clicking the button in the bottom right corner, or use the keyboard shortcut Ctrl+Shift+K/⌘+Shift+K.

      The button that opens the developer tools, screenshot

    4. Click the Forhåndsvis PDF (Preview PDF) button in the developer tools panel.

      Developer tools, screenshot