1 files changed, 92 insertions, 0 deletions
diff --git a/src/data/composite/data/withPropertiesFromList.js b/src/data/composite/data/withPropertiesFromList.js
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+++ b/src/data/composite/data/withPropertiesFromList.js
@@ -0,0 +1,92 @@
+// Gets the listed properties from each of a list of objects, providing lists
+// of property values each into a dependency prefixed with the same name as the
+// list (by default).
+//
+// Like withPropertyFromList, this doesn't alter indices.
+//
+// See also:
+//  - withPropertiesFromObject
+//  - withPropertyFromList
+//
+// More list utilities:
+//  - excludeFromList
+//  - fillMissingListItems
+//  - withFilteredList, withMappedList, withSortedList
+//  - withFlattenedList, withUnflattenedList
+//
+
+import {input, templateCompositeFrom} from '#composite';
+import {isString, validateArrayItems} from '#validators';
+
+export default templateCompositeFrom({
+  annotation: `withPropertiesFromList`,
+
+  inputs: {
+    list: input({type: 'array'}),
+
+    properties: input({
+      validate: validateArrayItems(isString),
+    }),
+
+    prefix: input.staticValue({type: 'string', defaultValue: null}),
+  },
+
+  outputs: ({
+    [input.staticDependency('list')]: list,
+    [input.staticValue('properties')]: properties,
+    [input.staticValue('prefix')]: prefix,
+  }) =>
+    (properties
+      ? properties.map(property =>
+          (prefix
+            ? `${prefix}.${property}`
+         : list
+            ? `${list}.${property}`
+            : `#list.${property}`))
+      : ['#lists']),
+
+  steps: () => [
+    {
+      dependencies: [input('list'), input('properties')],
+      compute: (continuation, {
+        [input('list')]: list,
+        [input('properties')]: properties,
+      }) => continuation({
+        ['#lists']:
+          Object.fromEntries(
+            properties.map(property => [
+              property,
+              list.map(item => item[property] ?? null),
+            ])),
+      }),
+    },
+
+    {
+      dependencies: [
+        input.staticDependency('list'),
+        input.staticValue('properties'),
+        input.staticValue('prefix'),
+        '#lists',
+      ],
+
+      compute: (continuation, {
+        [input.staticDependency('list')]: list,
+        [input.staticValue('properties')]: properties,
+        [input.staticValue('prefix')]: prefix,
+        ['#lists']: lists,
+      }) =>
+        (properties
+          ? continuation(
+              Object.fromEntries(
+                properties.map(property => [
+                  (prefix
+                    ? `${prefix}.${property}`
+                 : list
+                    ? `${list}.${property}`
+                    : `#list.${property}`),
+                  lists[property],
+                ])))
+          : continuation({'#lists': lists})),
+    },
+  ],
+});