Preview images and HTML

Images and HTML files open in the side panel preview, next to your chat in DataMind Oda. This page covers the image viewer and its zoom, and the two ways an HTML file can be shown.

The preview pane itself, the viewer dropdown and Reload are described in Preview files in Oda; the other viewers have their own pages: Preview PDFs and Office files and Preview spreadsheets.

View an image

Open the file in the preview, from a file card or by clicking the file.

• PNG, JPEG, GIF, WebP, BMP, ICO and SVG files open as pictures in a rounded viewer.
• An image opens at Fit width: it fits the width of the pane, and an image smaller than the pane keeps its natural size.
• While the file loads, the pane shows Reading….
• An SVG file is displayed as a picture and its code does not run.

Zoom an image

A floating control at the bottom edge of the pane gives you Fit width and fixed zoom steps.

• Move the pointer into the bottom strip of the pane to bring the control up; on a touch screen it stays visible.
• The minus and plus buttons step by 25%, and the menu offers Fit width, 25%, 50%, 100%, 150% and 200%.
• Fit width is the default and follows the pane when you resize it. At 100% the image is shown at its natural size, and the steps run from 25% to 400%.
• On a trackpad, pinch to zoom; the image zooms around the pointer and the percentage follows the gesture.
• Zooming keeps the same picture on screen, so an animated image keeps playing.
• The zoom belongs to the preview tab and is kept while the tab is open; closing the tab resets it, and the next preview opens at Fit width again.
• The preview does not pan by dragging; scroll the pane to move around a zoomed-in image.
• The same floating control appears on PDF previews.

Preview an HTML file

An HTML file opens as a safe, static view: the page is shown without running its scripts.

• Scripts do not run, links do not navigate, forms cannot be submitted, and the page cannot load frames or send requests over the network.
• Styles written in the file and embedded images stay; images stored next to the file are shown as well.
• Linked stylesheets and scripts are not loaded in this mode.
• HTML previews have no zoom control; the floating control belongs to image and PDF previews.

Run an HTML page's scripts

Turn on Interactive HTML preview in Settings > Developer > Advanced features. The change applies immediately and the preview reloads in the new mode; Advanced features lists the other switches.

• Scripts run in a closed frame: the page cannot reach DataMind Oda itself, and the preview reads only the scripts and stylesheets the page names directly, from the file's folder.
• Pages that pull files in through code, such as module imports, CSS imports or fetch calls, do not get those files.
• Limits: the page and the files it references are read up to 32 MiB together, 4 MiB per script or stylesheet, up to 64 files; images are capped at 4 MiB each, 16 MiB together, up to 256 images.
• If a referenced script or stylesheet cannot be read, is not valid text, or a limit is exceeded, the preview fails instead of showing a partial page. A single image that cannot be read stays a broken image and shows its alt text.

When a file cannot be shown

The preview says what went wrong; Reload in the preview header reads the file again.

• An image that cannot be shown says This image could not be displayed.
• An image the preview cannot read in full says Image preview requires the complete file contents.; a partial picture is never shown.
• An HTML file that cannot be prepared says This HTML document could not be previewed. A referenced file that cannot be read, and a file that is not valid text, are common causes.
• If only one image on the page is missing, the page still opens and the image shows as broken with its alt text.

Questions, answered

Which image formats can I view?

PNG, JPEG, GIF, WebP, BMP, ICO and SVG. A format with no preview shows its file icon and an explanation; open those files in another application.

Why does a small image not fill the pane?

Fit width only shrinks an image that is wider than the pane. A smaller image keeps its natural size and is not enlarged; use the zoom control if you want it larger.

How do I zoom an image?

Use the floating control at the bottom of the pane: the minus and plus buttons step by 25%, and the menu offers Fit width, 25%, 50%, 100%, 150% and 200%. The range runs from 25% to 400%, and 100% is the image at its natural size.

Where is the zoom control?

It floats at the bottom of the pane. With a mouse, move the pointer into the bottom strip to bring it up; it stays while you hover over it, focus it with the keyboard or keep its menu open. On a touch screen it stays visible.

Does my zoom stay when I switch tabs?

Yes. The zoom belongs to the preview tab and is kept while the tab is open. Closing the tab resets it, so a newly opened preview starts at Fit width.

Can I drag the image to move around it?

No. The preview does not pan by dragging; scroll the pane to move around a zoomed-in image.

Why do the scripts in my HTML file not run?

HTML previews are static by default: scripts do not run, links do not navigate, and nothing is loaded from the network. To let the page run its scripts, turn on Interactive HTML preview.

How do I turn on interactive HTML previews?

Open Settings > Developer > Advanced features and turn on Interactive HTML preview. The preview reloads in the new mode. Like the other advanced features, it is off by default and asks you to accept its risks the first time you turn it on; Memory, skills and connectors covers that settings area. On a computer that cannot offer it, the switch reads Not available on this computer yet.

Is it safe to open an HTML file Oda wrote?

The static preview never runs scripts, so the file shows as a picture of the page. With Interactive HTML preview on, scripts run inside a closed frame that cannot reach DataMind Oda itself or read other files from your computer. An interactive page can still show fake prompts or try to reach services on your computer or network, so keep the switch off for files you do not trust.

What happens when a page loads too many files?

The preview fails instead of showing a partial page. It reads the page and its referenced files up to 32 MiB together, 4 MiB per script or stylesheet, up to 64 files; images are capped at 4 MiB each, 16 MiB together, up to 256 images. A single image that cannot be read stays a broken image; it does not fail the page.

Can I read an HTML or SVG file as text?

Yes. Both are text files, so the viewer dropdown offers Plain text next to HTML or Image; choose it to read the source. The dropdown is described in Preview files in Oda.