AEM 6.4 and InDesign Server workflows demystified

For many versions, Adobe Experience Manager has included support for parsing InDesign documents via InDesign Server. AEM admins could use pre-built workflow steps to send an InDesign document or InDesign Snippet to InDesign Server along with a set of scripts that InDesign Server would execute against the payload. It was possible to execute multiple scripts in sequence on the same payload, which was handy but not particularly efficient as it would invoke InDesign Server as many times as you had scripts in the workflow. In AEM 6.3, the workflow component matured to make the workflows more efficient, and to include a set of functions that help InDesign Server access content in AEM and to post output documents back to AEM for further processing. In AEM 6.4, the workflow component added a configuration to permit any MIME-type as the payload for InDesign Server, opening up a whole new set of use cases for AEM and InDesign Server.

Scripts Deconstructed

The InDesign Server workflow component is called Media Extraction. It began life as a way to extract the text, images and metadata from InDesign documents, and it’s a core part of the built-in DAM Update Asset workflow today. Media Extraction has a lot of power as a workflow ingredient, however, if you know how to use it. Let’s explore how the Media Extraction workflow component works in AEM 6.4.

Media Extraction works by sending a payload to InDesign Server, consisting of a document and a script that InDesign Server executes on the document. As stated above, earlier incarnations only allowed the payload to include an InDesign Document (.indd) or InDesign Snippet (.idms), but 6.4 lets us send any document, as long as it passes our MIME-type filter. You can specify the MIME-type in the Process Arguments section of the workflow step. It helps to know the MIME-type of your content. You can use one of the many resources online to help identify common MIMI-types, but you may want to upload a file of the desired type to AEM and then examine its /jcr:content/metadata/dam:MIMEtype node to see what AEM thinks it is.

MIME Types

Specify the allowed MIME types for your scripts. The default is InDesign and InDesign Snippet.

You will also need to send a script that can process the payload and return the resulting file back to AEM. The Media Extraction workflow component reads and sends .jsx files, which contain the actual script code, to your InDesign Server. The built-in scripts are located at /libs/settings/dam/indesign/scripts/ and you should not move or change them. You can copy them to /apps/settings/dam/indesign/scripts/, or leave them in place and put your own scripts in /apps/settings/dam/indesign/scripts/. The critical thing to know is that the .jsx files are actually script fragments, and that they are designed to be concatenated into one script at runtime.

Scripts are concatenated from top to bottom in the list of scripts specified in Process Arguments

There are four sections in Process Arguments: ExtendScript Library, Init Script, Extend Scripts, and Cleanup Script. It is not recommended to modify the ExtendScript Library, located at /libs/settings/dam/indesign/scripts/cq-lib.jsx, as it provides important functions related to processing the inbound payload and to returning the resulting file back to AEM. Read and understand the helper functions provided by the ExtendScript library; you will be glad you did.

If you look at the default Init Script, located at /libs/settings/dam/indesign/scripts/Init.jsx, you’ll see that it contains an unclosed try {. This try { encloses the scripts indicated in the Extend Scripts section, and it closes in the Cleanup Script, located at /libs/settings/dam/indesign/scripts/Cleanup.jsx It continues with a catch{}, as expected, for error handling. This means that each of the Extend Scripts can leverage the work done and functions defined by the preceding scripts, including the ExtendScript Library and the Init Script, as the workflow component will combine the jsx files into one before sending the single, combined script to InDesign Server.

If you do not specify an Init Script and a Cleanup Script, the Media Extraction component will use the default scripts. Study these two scripts to see how to prepare to handle the inbound payload, how to process errors, and how to clean up the temporary files mess left during your processing. It is a good idea to use the existing Init.jsx and Cleanup.jsx files as the starting and ending points for your solution, so make copies (and name them something that stands out!) in /apps/settings/dam/indesign/scripts/ and modify those for production.

Example, please

Let’s look at an example called IDSBasedThumbnails, that you can download and install from github. The package contains the scripts and a workflow model, which performs the following actions on PDF, AI, PS or EPS files:

  • Sends the file to InDesign Server as a payload
  • Places, scales and centers the document on a new InDesign document
  • Exports the new document as thumbnails (PNG and JPEG)
  • Puts the exported files back in the repository at /jcr:content/renditions/
  • Wipes out the debris and closes InDesign Server

You might be asking why would anyone want to do this? Well, it turns out that AEM doesn’t have native rendering for EPS files, and the default DAM Update Asset workflow uses ImageMagick to generate previews from EPS files. I thought that it would be better to use InDesign Server, as it can handle not only EPS files, but also PDF, AI, PS and a whole set of other asset types. In addition, InDesign can simulate overprints and flatten complex transparency during the export, which makes it a very accurate way to deliver color-managed previews for assets used in printing processes. Think of packaging, where there’s a lot of use of overprinting varnishes and spot colors. Also, InDesign Server is super fast at making these renditions, operates as a dedicated image processing server, and can scale to meet demand without impacting the AEM Server. Let’s dig in to the workflow and see some example output.

MIME-type and ExtendScripts for making thumbnails with InDesign Server

MIME-type and ExtendScripts for making thumbnails with InDesign Server

As you can see above, we have many allowed MIME-types to cover the various assets we want to preview. If you try to run the workflow on a Word document, it will not work, as it won’t pass the initial MIME test. We’ve left the ExtendScript Library alone, but we’ve made new Init.jsx and Cleanup.jsx files that focused specifically on non-InDesign documents as payloads. The bulk of the work happens in EPSThumbnailExport.jsx, and we’ll highlight some of that script here.

The function called exportThumbnail() does the most of the work, and there’s a helper function called myGetBounds() at the end that returns the dimensions of the rectangle contained within the margins of the page. I’ve not included that below. Also, I’ve included comments to help explain what each of the sections of code is doing. Know that many of the inputs of the exportThumbnails() function are defined by the ExtendScript Library and the Init Script, which is why those are so important to read and understand.

function exportThumbnail(document, folderName, fileName, resourcePath, host, credentials) {
    var myDocument = app.documents.add();
    //set the margins to 0
    myDocument.marginPreferences.top = 0;
    myDocument.marginPreferences.left = 0;
    myDocument.marginPreferences.bottom = 0;
    myDocument.marginPreferences.right = 0;

    //The following assumes that your default master spread contains two facing pages.
    //We set the margins on the master spread to 0 as well, on the left and right pages
    myDocument.masterSpreads.item(0).pages.item(0).marginPreferences.top = 0;
    myDocument.masterSpreads.item(0).pages.item(0).marginPreferences.left = 0;
    myDocument.masterSpreads.item(0).pages.item(0).marginPreferences.bottom = 0;
    myDocument.masterSpreads.item(0).pages.item(0).marginPreferences.right = 0;
    myDocument.masterSpreads.item(0).pages.item(1).marginPreferences.top = 0;
    myDocument.masterSpreads.item(0).pages.item(1).marginPreferences.left = 0;
    myDocument.masterSpreads.item(0).pages.item(1).marginPreferences.bottom = 0;
    myDocument.masterSpreads.item(0).pages.item(1).marginPreferences.right = 0;

    //We set the page width and height to 319px, with portrait orientation
    myDocument.documentPreferences.pageHeight = "319px";
    myDocument.documentPreferences.pageWidth = "319px";
    myDocument.documentPreferences.pageOrientation = PageOrientation.portrait;

    //One page only
    myDocument.documentPreferences.pagesPerDocument = 1;

    //These settings control how InDesign Server handles black ink.
    //False means that InDesign will attempt to display how the black ink 
    //will interact with the substrate and the other inks in the job.
    //True will use a faster but less accurate model. The faster, less accurate model 
    //is the default behavior in InDesign, which is why we need to change the setting here.
    app.colorSettings.idealizedBlackToExport = false;
    app.colorSettings.idealizedBlackToScreen = false;


    //PNG export options here. 
    //Disable anti-alias to hide boundaries between atomic regions
    //created by transparency flattening
    app.pngExportPreferences.antiAlias = false;

    //All pages must be exported for PNG. We only have 1 page, 
    //but we need to specify the range
    app.pngExportPreferences.pngExportRange = PNGExportRangeEnum.EXPORT_ALL;

    //We want to simutate overprinting. This works 
    //in conjunction with the black setting above.
    app.pngExportPreferences.simulateOverprint = true;

    //We want the color space to be RGB.
    app.pngExportPreferences.pngColorSpace = PNGColorSpaceEnum.RGB;

    //We want a high quality PNG
    app.pngExportPreferences.pngQuality = PNGQualityEnum.HIGH;

    //Resolution set to 72 to generate 319 x 319 preview. 
    //We will adjust for each preview size.
    app.pngExportPreferences.exportResolution = 72;

    //Enable PNG transparency
    app.pngExportPreferences.transparentBackground = true;

    //JPEG export options here. The same settings apply for JPEG as for PNG
    app.jpegExportPreferences.antiAlias = false;
    app.jpegExportPreferences.simulateOverprint = true;
    app.jpegExportPreferences.jpegQuality = JPEGOptionsQuality.MAXIMUM;

    //Resolution set to 300 for high quality JPEG for zooming.
    app.jpegExportPreferences.exportResolution = 300;

    //Prepare for the thumbnail files
    var jpegRendition=new File(exportFolderThumbnail+"/"+"cq5dam.rendition.jpg");
    var thumbnail319=new File(exportFolderThumbnail+"/"+"cq5dam.thumbnail.319.319.png");
    var thumbnail140=new File(exportFolderThumbnail+"/"+"cq5dam.thumbnail.140.140.png");
    var thumbnail48=new File(exportFolderThumbnail+"/"+"cq5dam.thumbnail.48.48.png");
    var thumbnail1280=new File(exportFolderThumbnail+"/"+"cq5dam.web.1280.1280.png");

    //Create a new page in the document
    var myPage = myDocument.pages.item(0);

    //Get the page size as an array
    var myBounds = myGetBounds(myDocument, myPage);

    //Create a new text frame
    var myImageFrame = myDocument.pages.item(0).rectangles.add();

    //Make the image frame fill the page
    myImageFrame.geometricBounds = myBounds;

    //Ensure that the placed file will center in the frame and fit proportiionally
    myDocument.frameFittingOptions.properties.fittingAlignment=AnchorPoint.TOP_LEFT_ANCHOR;
    myDocument.frameFittingOptions.properties.fittingOnEmptyFrame=EmptyFrameFittingOptions.FILL_PROPORTIONALLY;
    myImageFrame.frameFittingOptions.properties.fittingAlignment=AnchorPoint.TOP_LEFT_ANCHOR;
    myImageFrame.frameFittingOptions.properties.fittingOnEmptyFrame=EmptyFrameFittingOptions.FILL_PROPORTIONALLY;

    //Remove the black stroke on the frame
    myImageFrame.strokeWeight = 0;  

    //Place the payload into the frame
    myImageFrame.place(sourceFile);

    //Fit the payload in the frame proportionally and centered
    myImageFrame.fit(FitOptions.PROPORTIONALLY);

    //Export the JPEG Rendition
    myImageFrame.exportFile(ExportFormat.JPG, jpegRendition);

    //Export the 319 thumbnail
    myImageFrame.exportFile(ExportFormat.PNG_FORMAT, thumbnail319);

    //adjust the resolution and export the 140 thumbnail
    app.pngExportPreferences.exportResolution = 32;
    myImageFrame.exportFile(ExportFormat.PNG_FORMAT, thumbnail140);

    //adjust the resolution and export the 48 thumbnail
    app.pngExportPreferences.exportResolution = 11;
    myImageFrame.exportFile(ExportFormat.PNG_FORMAT, thumbnail48);

    //adjust the resolution and export the 1280 thumbnail
    app.pngExportPreferences.exportResolution = 289;
    myImageFrame.exportFile(ExportFormat.PNG_FORMAT, thumbnail1280);

    //Close the temporary document without saving
    myDocument.close(SaveOptions.NO);

    //==== send files to AEM ====
    app.consoleout('Posting this file to AEM: ' + "cq5dam.rendition.jpg");
    app.consoleout('Posting to location: ' + target);
    putResource (host, credentials, jpegRendition, "cq5dam.rendition.jpg", 'image/jpeg', target);

    app.consoleout('Posting this file to AEM: ' + "cq5dam.thumbnail.140.140.png");
    app.consoleout('Posting to location: ' + target);
    putResource (host, credentials, thumbnail140, "cq5dam.thumbnail.140.140.png", 'image/png', target);

    app.consoleout('Posting this file to AEM: ' + "cq5dam.thumbnail.48.48.png");
    app.consoleout('Posting to location: ' + target);
    putResource (host, credentials, thumbnail48, "cq5dam.thumbnail.48.48.png", 'image/png', target);

    app.consoleout('Posting this file to AEM: ' + "cq5dam.web.1280.1280.png");
    app.consoleout('Posting to location: ' + target);
    putResource (host, credentials, thumbnail1280, "cq5dam.web.1280.1280.png", 'image/png', target);

    app.consoleout('Posting this file to AEM: ' + "cq5dam.thumbnail.319.319.png");
    app.consoleout('Posting to location: ' + target);
    putResource (host, credentials, thumbnail319, "cq5dam.thumbnail.319.319.png", 'image/png', target);

}

Once this script completes and all of the images have been written back to AEM via the putResource() calls, the Cleanup Script runs.

The result of this script is that all of the thumbnails for the specified Asset in DAM have been replaced with new thumbnails generated by InDesign Server. Here are some before and after images to give you an idea of the difference and why this model could be useful.

Previews without new workflow

Here are two EPS files and one PDF uploaded to DAM. ImageMagick preview has failed to generate a preview of the EPS files, and the PDF file shows no overprinting.

In order to run the workflow, you need to have InDesign Server installed, running, and your AEM instance needs to be configured to use InDesign Server. You can either open the workflow called DAM Update Asset with IDS Previews and run it on an asset from the Workflows panel, or you can open an asset and choose Run Workflow from the bottom of the Timeline panel for a specific asset. As configured, the workflow can’t run on a folder, since the MIME-Type filter doesn’t pass folders, so you need to run it one at a time on each asset. When you do, you will see the following result, and pay close attention to the difference in the PDF thumbnail:

Once the workflow generates previews, the new thumbnails replace the existing thumbnails with color accurate, overprint-simulated previews.

The PDF thumbnail now properly respects the overprint settings in the PDF, as well as in the EPS file. This is critical in managing assets that are designed to support print workflows that make use of overprinting and multi-ink composite colors, such as packaging and book covers. You might be wondering about why the previews for the CMYK Overprints.pdf and CMYK Overprints.eps are cropped differently. This is due to the way that InDesign interprets artwork boundaries when it imports assets. InDesign uses the page boundaries as defined in the EPS file when placing onto the page. PDF files can and often do have a number of boundaries available. InDesign, by default, will select the Bounding Box (Visible Layers Only) if it is available. This box is defined by the authoring application and typically exactly bounds the edges of any visible objects on the page as determined by layer visibility. You can learn more about PDF Bounding Boxes at this InDesign Secrets article.

InDesign defaults to the Bounding Box (Visible Layers Only) when importing PDF. You need to adjust the import preferences in your script if you want to change the default PDF import behavior.

InDesign defaults to the Bounding Box (Visible Layers Only) when importing PDF. You need to adjust the import preferences in your script if you want to change the default PDF import behavior.

The bounding boxes constants are: PDFCrop.cropPDF, PDFCrop.cropArt, PDFCrop.cropTrim, PDFCrop.cropBleed, PDFCrop.cropMedia, PDFCrop.cropContentAllLayers, PDFCrop.cropContentVisibleLayers. You can add a line before myImageFrame.place(sourceFile) to change the behavior to match how InDesign imports EPS files:

app.pdfPlacePreferences.pdfCrop = PDFCrop.cropMedia;

If you make the change, you will need to save the JSX, then reimport the JSX to your workflow, then re-sync your workflow in order for it to become available. Importing the JSX can be a confusing step, so let’s discuss that briefly. The built-in asset browser for JSX files doesn’t let you select a JSX from the file tree. It’s a known issue and it will be fixed in a later version of AEM, but for now, the Search bar is your best friend. Just enter the name of the JSX you want to import, and it’ll appear in the search results. Select it, and you’re all set.

Use the Search bar to reimport your modified JSX to the workflow step.

Use the Search bar to reimport your modified JSX to the workflow step.

Once you re-import the JSX, the change is automatically saved to the workflow, but the workflow needs to be synced to become active. Once you tap the Sync button, you’re ready to go.

Be sure to tap Sync after updating the workflow step.

Be sure to tap Sync after updating the workflow step.

After you update the JSX and re-sync the workflow, the PDF and EPS thumbnails will be similar.

After you update the JSX and re-sync the workflow, the PDF and EPS thumbnails will be similar.

You could also modify the DAM Update Asset workflow to remove ImageMagick and/or the built-in PDF renderers and replace them with a new step. You would likely want to expand the script to handle multi-page PDF and AI files, however. If you’d like to explore this option, here’s a great starting point from Mike Edel for importing multi-page PDF and AI into InDesign via scripting.

Conclusion

Being able to use InDesign Server to generate better previews for EPS and PDF and AI files is a nice new benefit of the new MIME-type options in the Media Extraction workflow. This is a relatively trivial example of what a developer can do with this new capability, however. You could create a workflow that sends a whole package of items to InDesign Server, which would do some action on those items, and then return a new file or other data to AEM. Integrators can develop new editorial and creative tools based on this new capability to enhance existing inDesign documents or create entirely new ones from scratch. We hope you will be inspired to add more InDesign Server to your AEM Assets workflows.

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