writing-vizro-yaml

Vizro YAML & Component Reference

Critical Mistakes to Avoid

Each mistake below is expanded with code examples and fixes in yaml-reference.md.

1. @capture("graph") receives a DataFrame — use data_frame directly; never re-lookup via data_manager[data_frame] (causes blank charts).
2. data_manager is not subscriptable — pre-process on raw DataFrame, then register.
3. Custom _target_ needs module prefix — _target_: custom_charts.my_chart, not _target_: my_chart.
4. type: figure has no title field — KPI titles go in _target_: kpi_card args.
5. type: ag_grid requires _target_: dash_ag_grid.
6. Parameter targets — format: "component_id.argument_name", not "component_id.figure".
7. Quote YAML special chars in column names — column: "Version #" (unquoted # starts a comment).
8. Filter targets: — omit when you want to apply it to all components on the page whose data source includes defined filter column.
9. Grid must be rectangular — same component index must span same columns in every row.
10. Column type consistency — filter column must have same dtype across all targeted datasets.

Quick Patterns

# Standard chart
- figure:
    _target_: bar
    data_frame: sales_data
    x: region
    y: revenue
  type: graph
  title: Revenue by Region

# KPI card (title inside figure args, NOT on component)
- figure:
    _target_: kpi_card
    data_frame: kpi_data
    value_column: Revenue
    title: Total Revenue
    value_format: "${value:,.0f}"
  type: figure

# AG Grid table
- figure:
    _target_: dash_ag_grid
    data_frame: sales_data
  type: ag_grid
  title: Sales Data

# Filter with targets
controls:
  - column: region
    targets: [chart_1, chart_2]
    type: filter

Key Imports

import vizro.models as vm
from vizro import Vizro
import vizro.plotly.express as px
from vizro.tables import dash_ag_grid
from vizro.figures import kpi_card, kpi_card_reference
from vizro.models.types import capture
from vizro.managers import data_manager
from vizro.themes import palettes, colors

Deep Dive

Load yaml-reference.md when you need expanded guidance. Key sections to search for:

Need	Search for
App structure	## End-to-End Data Flow
Data registration	## Data Registration
Custom charts	## Custom Charts
AG Grid (heatmap, inline bars)	## AG Grid Tables
Containers / Tabs	## Containers or ## Tabs
Expanded mistake fixes	## Critical Mistakes