feat: Add ability to specify arbitrary aggregations in json (#250)

* feat: Add ability to specify arbitrary aggregations in json * jheer comments
uwdata · Jan 11, 2024 · a987652 · a987652
1 parent 1faee8b
commit a987652
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Showing 2 changed files with 16 additions and 9 deletions.
diff --git a/packages/vgplot/src/spec/parse-spec.js b/packages/vgplot/src/spec/parse-spec.js
@@ -155,8 +155,8 @@ export class ParseContext {
 
   maybeTransform(value) {
     if (isObject(value)) {
-      return value.expr
-        ? parseExpression(value, this)
+      return value.expr ? parseExpression(value, this)
+        : value.agg ? parseAggregation(value, this)
         : parseTransform(value, this);
     }
   }
@@ -363,8 +363,9 @@ function parseInteractor(spec, ctx) {
   return fn(options);
 }
 
-function parseExpression(spec, ctx) {
-  const { expr, label } = spec;
+function parseExpression(spec, ctx, key = 'expr') {
+  const { label } = spec;
+  const expr = spec[key];
   const tokens = expr.split(/(\\'|\\"|"(?:\\"|[^"])*"|'(?:\\'|[^'])*'|\$\w+)/g);
   const spans = [''];
   const exprs = [];
@@ -382,6 +383,11 @@ function parseExpression(spec, ctx) {
   return sql(spans, ...exprs).annotate({ label });
 }
 
+function parseAggregation(spec, ctx) {
+  return parseExpression(spec, ctx, 'agg').annotate({aggregate: true});
+}
+
+
 function parseTransform(spec, ctx) {
   const { transforms } = ctx;
   let name;

diff --git a/packages/vgplot/src/spec/to-module.js b/packages/vgplot/src/spec/to-module.js
@@ -143,8 +143,8 @@ class CodegenContext extends ParseContext {
 
   maybeTransform(value) {
     if (isObject(value)) {
-      return value.expr
-        ? parseExpression(value, this)
+      return value.expr ? parseExpression(value, this)
+	: value.agg ? parseExpression(value, this, 'agg', 'agg')
         : parseTransform(value, this);
     }
   }
@@ -162,8 +162,9 @@ class CodegenContext extends ParseContext {
   }
 }
 
-function parseExpression(spec, ctx) {
-  const { expr, label } = spec;
+function parseExpression(spec, ctx, key = 'expr', method = 'sql') {
+  const { label } = spec;
+  const expr = spec[key]
   const tokens = expr.split(/(\\'|\\"|"(?:\\"|[^"])*"|'(?:\\'|[^'])*'|\$\w+)/g);
   let str = '';
 
@@ -176,7 +177,7 @@ function parseExpression(spec, ctx) {
     }
   }
 
-  return `vg.sql\`${str}\``
+  return `vg.${method}\`${str}\``
     + (label ? `.annotate({ label: ${JSON.stringify(label)} })` : '');
 }