Custom Previews

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The Custom Previews plugin adds a special preview functionality to the asset context menu for its supported file extensions. The goal is to provide a better user experience for the file extensions where the standard JPG image shown by Celum is not suitable or not the desired behavior.

The label for the key of the menu item is customPreviews.menuTitle and can be customized via the {home}/appserver/lang/ files.


To be configured in {home}/appserver/conf/


type: String, required: yes, default: -, since v1.0.1

The license key for the plugin (product: customPreviews), provided by brix.


type: List of Long, required: no, default: - (visible for everybody)

If one or more user group ids are specified, then the plugin's menu entry is only visible for those user groups and super admins.


type: List of String, required: no, default: - (all previewers are available)

A list of the previewer beans for which the custom preview will be enabled.

Currently available: customPreviewsImagePreviewer, customPreviewsPdfPreviewer, customPreviewsOfficePreviewer.


type: List of String, required: no, default: gif

File extensions for which the image previewer is used. The specified extensions have to be a valid src for an img tag.



id: customPreviewsImagePreviewer, extensions: customPreviews.imagePreviewer.extensions

Shows the original file using an img tag.


id: customPreviewsImagePreviewer, extensions: pdf

Shows the PDF file using an iframe, so the browser's PDF viewer will display it.


id: customPreviewsImagePreviewer, extensions: doc, docx, xls, xlsx, ppt, pptx

Shows Microsoft Office documents via their free service There is no need to install Microsoft Office but the previewed file will be uploaded to the external site.


To be configured in {home}/appserver/lang/customMessages_{language}.properties.


The label for the context menu item and the title of the preview window.

Compatibility Matrix

Custom Previews CELUM
1.0 5.13.3
1.0.3 5.13.4 (tested with 6.4)
1.0.5 5.13.4+ (tested with 6.8)

Release Notes


Released 2019-01-15

Initial Version


Released 2019-01-28

Added license


Released 2021-01-08

Fixed office previewer, URL changed