From e2ea8c80fc3283e0e184dfe85b6e8645e74a7ac9 Mon Sep 17 00:00:00 2001
From: Krist Wongsuphasawat <krist.wongz@gmail.com>
Date: Wed, 5 Jun 2019 00:33:58 -0700
Subject: [PATCH] feat: add getDomain to ChannelEncoder

---
 .../src/encodeable/AbstractEncoder.ts         |  2 +-
 .../src/encodeable/ChannelEncoder.ts          | 28 ++++++++++++++++++-
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/packages/superset-ui-preset-chart-xy/src/encodeable/AbstractEncoder.ts b/packages/superset-ui-preset-chart-xy/src/encodeable/AbstractEncoder.ts
index 4a290a362..4dd9004b2 100644
--- a/packages/superset-ui-preset-chart-xy/src/encodeable/AbstractEncoder.ts
+++ b/packages/superset-ui-preset-chart-xy/src/encodeable/AbstractEncoder.ts
@@ -161,7 +161,7 @@ export default abstract class AbstractEncoder<
           // Only work for nominal channels now
           // TODO: Add support for numerical scale
           if (channelEncoder.definition.type === 'nominal') {
-            const domain = Array.from(new Set(data.map(channelEncoder.get)));
+            const domain = channelEncoder.getDomain(data) as string[];
 
             return domain.map((value: ChannelInput) => ({
               field,
diff --git a/packages/superset-ui-preset-chart-xy/src/encodeable/ChannelEncoder.ts b/packages/superset-ui-preset-chart-xy/src/encodeable/ChannelEncoder.ts
index 0d56918a9..44b0d3563 100644
--- a/packages/superset-ui-preset-chart-xy/src/encodeable/ChannelEncoder.ts
+++ b/packages/superset-ui-preset-chart-xy/src/encodeable/ChannelEncoder.ts
@@ -1,9 +1,10 @@
+import { extent as d3Extent } from 'd3-array';
 import { Value } from 'vega-lite/build/src/channeldef';
 import { extractFormatFromChannelDef } from './parsers/extractFormat';
 import extractScale, { ScaleAgent } from './parsers/extractScale';
 import extractGetter from './parsers/extractGetter';
 import { ChannelOptions, ChannelType, ChannelInput } from './types/Channel';
-import { PlainObject } from './types/Data';
+import { PlainObject, Dataset } from './types/Data';
 import {
   ChannelDef,
   isScaleFieldDef,
@@ -95,6 +96,31 @@ export default class ChannelEncoder<Def extends ChannelDef<Output>, Output exten
       : (value as T);
   }
 
+  getDomain(data: Dataset) {
+    if (isTypedFieldDef(this.definition)) {
+      const { type } = this.definition;
+      if (type === 'nominal' || type === 'ordinal') {
+        return Array.from(new Set(data.map(d => this.get(d)))) as string[];
+      } else if (type === 'quantitative') {
+        const extent = d3Extent(data, d => this.get<number>(d));
+        if (typeof extent[0] === 'undefined') {
+          return [0, 1];
+        }
+
+        return extent as [number, number];
+      } else if (type === 'temporal') {
+        const extent = d3Extent(data, d => this.get<number | Date>(d));
+        if (typeof extent[0] === 'undefined') {
+          return [0, 1];
+        }
+
+        return extent as [number, number] | [Date, Date];
+      }
+    }
+
+    return [];
+  }
+
   getTitle() {
     if (isFieldDef(this.definition)) {
       return this.definition.title || this.definition.field;