chart library
Purpose
Differentiated chart system, interaction language, and style quality bar. This workstream owns the chart rendering layer: the set of chart types (line, bar, area, scatter, KPI, table, etc.), their visual design language, interaction behaviors, and the overall aesthetic quality bar that makes Dataface dashboards look distinctive and professional. RJ Andrews leads the design direction. The chart library renders within dft-core's rendering pipeline but owns the design decisions: color palettes, typography, animation, responsiveness, and visual grammar. Adjacent to dft-core (which provides the rendering infrastructure) and dashboard-factory (which relies on chart-library quality for template polish).
Owner
- Data Graphics Designer and Engineer (RJ Andrews)
Initiatives
- M1 basic chart batch for analyst pilot — Planned, M1 — 5T Internal Pilot Ready, 1 / 1 tasks complete (100%)
- M2 exposed and documented chart properties — Planned, M2 — Internal Adoption + Design Partners, 0 / 0 tasks complete (0%)
- M2 good table chart — Planned, M2 — Internal Adoption + Design Partners, 0 / 0 tasks complete (0%)
- M2 semantic type behaviors — Planned, M2 — Internal Adoption + Design Partners, 1 / 2 tasks complete (50%)
- M2 style packages and evaluation ownership — Planned, M2 — Internal Adoption + Design Partners, 0 / 3 tasks complete (0%)
- M2 table formatting and linking architecture — Planned, M2 — Internal Adoption + Design Partners, 0 / 7 tasks complete (0%)
- M3 chart and visualization extensibility — Planned, M3 — Public Launch, 0 / 0 tasks complete (0%)
- M3 data-informed chart properties — Planned, M3 — Public Launch, 0 / 0 tasks complete (0%)
- M3 starter dashboard composition — Planned, M3 — Public Launch, 0 / 1 tasks complete (0%)
Tasks by Milestone
A runnable prototype path exists for visual language, chart defaults, interaction behavior, and differentiated styling, with concrete artifacts that prove the flow works end-to-end in the current codebase. Core assumptions are documented, known constraints are explicit, and the team can explain what is real versus mocked without ambiguity.
- Prototype gaps and follow-on capture Completed — Document top gaps and risks in interaction/accessibility polish that must be addressed next.
- Prototype implementation path Completed — Implement a runnable end-to-end prototype path for visual language system.
- Prototype validation and proof Completed — Validate chart default behavior with concrete proof artifacts and repeatable steps.
Internal analysts can execute at least one weekly real workflow with a stable basic chart batch in the 5T Analytics environment, without bespoke engineering intervention for every chart. M1 proves the functional chart foundation: the core chart types, working examples, and enough reliability to support repeated analyst use.
- M1 pilot chart batch CompletedPR #845PR at 2026-03-27T07:32:37-07:00 — Establish a functional batch of basic chart types for the analyst pilot, with chart behavior that is reliable enough fo…
- Choose primary sans typeface for Dataface Completed — Evaluate candidate sans typefaces for Dataface UI and chart surfaces, choose a primary family, and capture the decision…
- Define chart scaffold gray ladder and neutral roles Completed — Capture the chart scaffold gray research, lock the M1 neutral role model for titles, labels, guides, and surfaces, and…
- Define first default chart structure preset Planned — Investigate and define the first default chart structure preset for M1, including axis side posture, guide and grid phi…
- Define initial chart color palette system CompletedPR #815 — Research, define, document, and implement the first Dataface chart color system: the single-series blue, the default ca…
- Implement Inter as primary sans in Dataface charts CompletedPR #737PR at 2026-03-23T15:39:12-07:00 — Apply Inter as the primary sans-serif typeface for Dataface chart and data-dense UI surfaces, including numeric default…
- Implement tonal foundations for Dataface neutrals CompletedPR #763PR at 2026-03-24T03:18:22-07:00 — Implement the initial tonal foundation decisions for the Dataface neutral system: use #1A1A1A as the darkest default in…
- Investigate structure-level axis visibility config not applying in standard charts — Document why vega.config.axisX.labels=false is emitted but standard charts still render x-axis labels, including eviden…
- M1 consistent category color mapping across charts Planned — Investigate and design a top-level category color mapping system so repeated semantic values such as Accessories, Elect…
- M2 investigate chart dimension and plot-area control — Chart layout tuning exposed a gap between dashboard container sizing and actual chart drawing-area behavior. In the M1…
- Restructure chart family docs and navigation Completed — Rework the chart docs navigation around chart families, build stable family pages for line graphs, sector charts, bar c…
- Add chart subtitle support CompletedPR #831PR at 2026-03-26T22:33:54-07:00 — Add first-class subtitle support for chart rendering across the compile and render pipeline. Extend chart schema/types…
- Choose narrative serif typeface for Dataface CompletedPR #740PR at 2026-03-23T16:24:45-07:00 — Select a serif companion typeface for narrative headlines and selected annotation labels after the primary sans decisio…
- Define asymmetric independent and dependent axis treatments Completed — Research and define when Dataface should treat independent and dependent axes differently in chart structure and textur…
- Refine hero-vs-warms categorical palette Completed — Preserve the current hero-vs-warms draft, refine its support-band logic, and decide whether it should ship as a second…
The chart library has distinct style packages, evaluation ownership, reusable design assertions, semantic-type-aware behaviors, exposed and documented chart properties, and a good table chart baseline. The system is coherent enough for regular use by multiple internal teams and initial design partners, with a predictable response loop for issues and requests.
- Dual style packages — Establish at least two distinct chart style packages that pair structure and theme: one minimal analytic package inspir…
- Lock visual language v1 with RJ — Finalize differentiated chart styling system, typography, and interaction defaults with RJ Andrews.
- Adoption hardening for internal teams — Harden visual language system for repeated use across multiple internal teams and first design partners.
- Chart evaluation ownership and improvement — Take ownership of the existing chart-evaluation tooling for the chart library: use it on the chart corpus, learn its st…
- Define context-aware style system — Define the downstream context-aware style system for Dataface charts: when style decisions should vary by chart family,…
- Design assertions foundation — Produce an initial chart-library design-assertions corpus from chart exploration, with assertions structured to support…
- Design-partner feedback loop operations — Operationalize rapid feedback-to-fix loop for chart default behavior with explicit decision logs.
- M2 conditional formatting and row-level styling engine M2 table formatting and linking architecture — Implement conditional formatting primitives and row-level style application with deterministic rule ordering and confli…
- M2 in-cell visual encodings and sparkline consolidation M2 table formatting and linking architecture — Standardize in-cell bar and sparkline configuration under the table formatting model, including compatibility with exis…
- M2 linking actions for headers, rows, and cells M2 table formatting and linking architecture — Define and implement link/action behavior for table headers, rows, and cells including parameter templating and safe fa…
- M2 table config schema and precedence model M2 table formatting and linking architecture — Design the JSON schema for table formatting and linking with clear precedence across table, column, row, and cell scope…
- M2 table formatting survey and option inventory M2 table formatting and linking architecture — Research BI products and table libraries, then produce a normalized option inventory for column, row, and cell formatti…
- Quality standards and guardrails — Define and enforce quality standards for interaction/accessibility polish to keep output consistent as contributors exp…
- Terminology standards and synonym handling — Define strict product terminology for chart and visualization concepts while preserving backward-compatible interpretat…
- Consolidate semantic chart defaults and rendering control-surface follow-ons M2 semantic type behaviors — Bundle the recent chart-rendering follow-on backlog into one M2 task covering semantic axis behavior, temporal-axis lab…
- Implement BI and editorial numeric notation families M2 semantic type behaviors CompletedPR #762PR at 2026-03-24T02:41:22-07:00 — Implement Dataface support for BI and editorial numeric notation families across charts and related surfaces. Define th…
- M2 docs, examples, and QA matrix for table formatting M2 table formatting and linking architecture — Publish docs and reference examples, then validate behavior with a QA matrix covering common and edge-case formatting a…
- M2 research perceptual graphic-emphasis analysis beyond contrast — Research whether Dataface should develop a chart-analysis tool that goes beyond standard accessibility contrast checks…
- Vega-Lite format parity for tables and Python formatters M2 table formatting and linking architecture — Implement or reuse Python number/date formatting aligned with Vega-Lite format and formatType so style.columns value op…
Launch scope for the chart library is complete, externally explainable, and supportable: starter dashboard composition patterns exist beyond the playground, data-informed chart properties are driving more of the default behavior, documentation is publishable, and operational ownership is explicit. Remaining gaps are non-blocking, risk-assessed, and tracked as post-launch follow-up rather than unresolved launch debt.
- Launch docs and external readiness — Publish external-facing documentation and examples for chart default behavior that are executable by new users.
- Launch operations and reliability readiness — Finalize operational readiness for interaction/accessibility polish: telemetry, alerting, support ownership, and incide…
- Public launch scope completion — Complete launch-critical scope for visual language system with production-safe behavior and rollback clarity.
- feat: Brushing/selections with range variables — Add brushing and range-variable selections so charts can drive cross-filtered interactions and exploratory analysis.
- Launch-ready chart quality pass — Execute final quality pass on launch chart templates for consistency, readability, and performance.
- Starter dashboard composition patterns — Turn the basic chart corpus into deliberate starter dashboard patterns, beginning from playground examples and pushing…
- Optimization: Batch Vega-Lite chart rendering for ~30% speedup — Batch Vega-Lite rendering to reduce chart render overhead and target roughly 30% performance improvement.
Post-launch stabilization is complete for visual language, chart defaults, interaction behavior, and differentiated styling: recurring incidents are reduced, support burden is lower, and quality gates are enforced consistently before release. The team has a repeatable operating model for maintenance, regression prevention, and measured reliability improvements.
- Regression prevention and quality gates — Add or enforce regression gates around chart default behavior so release quality is sustained automatically.
- Sustainable operating model — Document and adopt sustainable operating model for interaction/accessibility polish across support, triage, and release…
- v1.0 stability and defect burn-down — Run stability program for visual language system with recurring defect burn-down and reliability trend tracking.
- Conditional Formatting — Implement conditional formatting primitives for the graph library to encode thresholds, exceptions, and trend states vi…
v1.2 delivers meaningful depth improvements in visual language, chart defaults, interaction behavior, and differentiated styling based on observed usage and retention signals, not just roadmap intent. Enhancements improve real customer outcomes, and release readiness is demonstrated through metrics, regression coverage, and clear migration guidance where relevant.
- Quality and performance improvements — Ship measurable quality/performance improvements in chart default behavior tied to user-facing outcomes.
- v1.2 depth expansion — Deliver depth expansion in visual language system prioritized by observed usage and retention outcomes.
- v1.2 release and migration readiness — Prepare v1.2 release/migration readiness for interaction/accessibility polish, including communication and upgrade guid…
Long-horizon opportunities for visual language, chart defaults, interaction behavior, and differentiated styling are captured as concrete hypotheses with user impact, prerequisites, and evaluation criteria. Ideas are ranked by strategic value and feasibility so future investment decisions can be made quickly with less rediscovery.
- Experiment design for future bets — Design validation experiments for interaction/accessibility polish so future bets can be tested before major investment.
- Future opportunity research — Capture long-horizon opportunities for visual language system with user impact and strategic fit.
- Prerequisite and dependency mapping — Map enabling prerequisites and dependencies for chart default behavior to reduce future startup cost.