malloy-gotchas-rendering

Rendering Gotchas

Read this before adding renderer annotations. These patterns cause most rendering issues.

One Tag Per Line

Each # annotation must be on its own line directly above the field. Never combine tags on one line.

// WRONG, will not work
# label="Revenue" # currency
revenue

// RIGHT
# label="Revenue"
# currency
revenue

No Fixed Scale on Measures

Use # currency (no scale) on measure definitions. The same measure renders at many granularities: usd0m turns $500 into $0.0M.

// WRONG on a measure definition
# currency=usd0m
measure: revenue is sum(total)

// RIGHT, no scale on measure
# currency
measure: revenue is sum(total)

Add scale (e.g., # currency=usd0m) only in views after confirming value ranges with queries.

# big_value Needs # label on Each Measure

# big_value
view: summary is {
  aggregate:
    # label="Revenue"
    # currency
    revenue

    # label="Orders"
    # number=auto
    order_count
}

Without # label, big_value cards show raw field names which are often unclear.

Sparkline Setup

Sparklines in # big_value require TWO things: a # hidden nested view AND a .sparkline= reference.

# big_value { sparkline=trend }
view: revenue_kpi is {
  aggregate:
    # label="Revenue"
    # currency
    revenue
  nest:
    # line_chart { size=spark }
    # hidden
    trend is { group_by: order_date, aggregate: revenue, order_by: order_date }
}

If the sparkline doesn't show: check that # hidden is on the nested view AND the view name matches .sparkline=.

Comparison Deltas

# big_value { comparison_field=prior_month comparison_label="vs Last Month" }
view: rev_delta is {
  aggregate:
    # label="Revenue"
    # currency
    revenue
    # hidden
    prior_month
}

Use down_is_good=true for metrics where decrease is positive (churn, defects).

# dashboard Layout