Image expression – images and icons¶
The image expression returns an image or an icon: an image uploaded to nexxcite, a glyph of an icon font, the Microsoft Entra profile picture of a user, or an image at an external address. Settings that show an image – icons of buttons and badges, avatars, image blocks – take an image expression.
1. At a glance¶
| Purpose | Returns an image or an icon that nexxcite can display |
| Typical use | Icons of buttons, app bar entries and quick filters, user avatars, product pictures from a web shop |
| Returns | A description of the image that image-capable settings understand – not a plain address |
| Related | Images, Icon fonts, Cache |
2. Settings¶
| Setting | Meaning | Used with source |
|---|---|---|
| "Source" | Where the image comes from: "Image", "Icon Font", "Entra Profile Picture" or "External Image" | – (default: "Image") |
| "Image" | An image uploaded under Admin Studio → Design → Images | "Image" |
| "Icon Font" | An icon font uploaded under Admin Studio → Design → Icon Fonts | "Icon Font" |
| "Icon" | The glyph of the icon font, chosen from a searchable grid | "Icon Font" |
| "Graph API Credentials" | The Microsoft Graph API credentials used to read the picture. Their app registration needs the application permission User.Read.All. |
"Entra Profile Picture" |
| "User" | An expression returning the object id or the user principal name (for example jane.doe@contoso.com) of the Entra user |
"Entra Profile Picture" |
| "Image URL" | An expression returning the address of the image – an absolute http:// or https:// address, or a path on this server starting with / |
"External Image" |
The editor shows a preview of the selected image or icon.
In settings that take an image, you can usually pick an image or icon directly; nexxcite then creates the image expression for you.
3. Behaviour¶
| Source | At evaluation |
|---|---|
| "Image", "Icon Font" | The uploaded image or the glyph is returned. If it was deleted, the result is empty and nothing is shown. |
| "Entra Profile Picture" | The picture is read from Microsoft on every evaluation and passed on to the browser. A user without a picture, an empty "User" or missing credentials show nothing – an avatar then falls back to the initials. |
| "External Image" | The address is passed to the browser, which loads the image. Addresses with another scheme (for example javascript: or data:) are rejected and nothing is shown. |
The browser of the user must be able to reach an external image address; nexxcite does not load it on the server.
4. Examples¶
Icon of a quick filter: Source "Icon Font", the font "Material Symbols", icon "assignment_ind".
Avatar of the assigned user: Source "Entra Profile Picture", Graph API credentials "Entra directory", User = field "E-mail" of the assigned user. Wrap it in a Cache expression with the e-mail address as key, because grids and app bars show it often.
Product picture: Source "External Image", Image URL = text expression
https://shop.example.com/images/ + field "Article number" + .jpg.
5. Limitations¶
- Entra profile pictures cost one request to Microsoft per evaluation (section 3). Without a cache, a grid with 50 rows sends 50 requests every time it is displayed.
- The result is meant for image-capable settings. Inserted into a text, it appears as technical text.