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Diffstat (limited to 'src/data/composite/data/withPropertiesFromList.js')
-rw-r--r-- | src/data/composite/data/withPropertiesFromList.js | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/src/data/composite/data/withPropertiesFromList.js b/src/data/composite/data/withPropertiesFromList.js new file mode 100644 index 0000000..76ba696 --- /dev/null +++ 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 +// - 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})), + }, + ], +}); |