Blank Vega Canvas
Use the built-in blank Vega starter to create a visual from first principles with the Power BI dataset already connected.
Template overview
Blank Vega Canvas is the minimal built-in template packaged with the current Ataytis Vega Studio visual. It is intended for authors who want full control and do not need a pre-built chart structure.
| Property | Blank Vega Canvas behavior |
|---|---|
| Provider | Vega |
| Dataset | Includes the Power BI-backed dataset reference named dataset. |
| Marks | Starts with an empty marks array. |
| Configuration | Uses fit-style autosizing with padding contained in the available viewport. |
| Theme defaults | Does not apply a pre-built visual theme. |
| Required fields | None at creation time; the fields you use depend entirely on the visual you author. |
How it works
When you choose the Vega creation path, the Studio loads the first included Vega template. Blank Vega Canvas supplies a schema reference, a connected dataset, empty marks, and template metadata. The create workflow resolves the starter into editable specification and configuration content and opens it in the Studio.
{
"$schema": "<bundled Vega schema URL>",
"data": [
{ "name": "dataset" }
],
"marks": [],
"usermeta": {
"...": "Studio template metadata and configuration"
}
}Create a visual from Blank Vega Canvas
- 1
Assign any known Power BI fields
Add the columns and measures you expect to use to the Values well. You can adjust them later.
- 2
Open the new-specification workflow
Choose to create a new specification and select the Vega creation method.
- 3
Create the starter
The Studio prepares Blank Vega Canvas automatically; there is no additional built-in template picker in the current version.
- 4
Inspect the dataset
Open Data table and confirm field names and value types before writing marks.
- 5
Build in layers
Add derived data and transforms, then scales, guides, marks, labels, signals, and interactions.
- 6
Apply and validate
Use manual update until the structure is stable, then test the result in full preview and on the report canvas.
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Blank Vega Canvas immediately after creation
Show the empty preview and starter JSON before any marks have been added.
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Blank canvas developed into a finished visual
Show a before-and-after comparison using the same specification after datasets, scales, marks, labels, and interactions have been added.
Use cases
- Designing a completely original visual without removing preset chart logic.
- Porting an existing Vega specification and adapting its data source to
dataset. - Learning how Power BI fields, Studio helper fields, and Vega marks fit together.
- Building a clean source visual that will later be exported as a reusable template.
- Testing small Vega concepts, transforms, or interactions in isolation.
Common issues
| Symptom | Likely cause | Resolution |
|---|---|---|
| The preview remains empty | The starter intentionally has no marks. | Add at least one mark and confirm its source dataset and encodings. |
| The mark exists but no data appears | A field name does not match the Data table or no field is assigned. | Inspect dataset, then correct the field reference or Values assignment. |
| The visual is clipped | The design uses fixed dimensions or ignores padding. | Use responsive sizing, fit autosize behavior, or preview scrollbars while diagnosing. |
| An external example fails | It targets a different Vega version, embeds inline data, or expects browser APIs unavailable in the host. | Check Diagnostics, adapt the data source, and test features against the Studio's bundled runtime. |