README

Neos backend module that allows for creating and testing ESCR projections on the fly

Usage

install via composer:

composer require wwwision/projection-playground

Note At the time of writing, the neos/contentrepository-core package is not yet available on packagist You can download it from GitHub to your distribution folder: https://github.com/neos/neos-development-collection/tree/9.0/Neos.ContentRepository.Core and install everything via composer require wwwision/projection-playground neos/contentrepository-core:@dev

Afterwards, if you log into the Neos Backend as an Administrator, you can navigate to the new backend module at /neos/administration/projection-playground and start playing.

Projections

The projection logic can be written in JavaScript. This package supports a subset of the EventStoreDB projection syntax (see Documentation)

Example projections

Count all events

fromAll()
.when({
 $init: () => ({count: 0}),
 $any: (s, e) => {
 s.count ++;
 }
})

Count created node types

...and transform the result to order them by most used type

fromAll()
.when({
 NodeAggregateWithNodeWasCreated: (s, e) => {
 const nodeType = e.body.nodeTypeName;
 s[nodeType] = (s[nodeType] ?? 0) + 1;
 }
}).transformBy(s => Object.fromEntries(Object.entries(s).sort((a, b) => b[1] - a[1])))

Aggregate events by their weekday

...and transform the result to order them by most popular day

fromAll()
.when({
 $any: (s, e) => {
 const timestamp = e.metadataRaw['initiatingTimestamp'];
 if (!timestamp) {
 return;
 }
 const date = new Date(timestamp);
 const weekDay = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"][date.getDay()];
 s[weekDay] = (s[weekDay] ?? 0) + 1;
 }
}).transformBy(s => Object.fromEntries(Object.entries(s).sort((a, b) => b[1] - a[1])))

Disclaimer

This project is not endorsed by Event Store Ltd.