Projections
You can combine specifications to create a projection. This is how you will populate your user interface.
Start your specification as before, and then use the select method to project the results through a new specification.
const projectsWithNamesCreatedByUser = model.given(User).match(u =>
Project.by(u)
.select(p => ({
projectId: p.id,
names: ProjectName.of(p)
.select(n => n.value)
}))
);Let's give names to the other projects so that we can see them.
await j.fact(new ProjectName(projectB, "Pinecrest School Expansion", []));
await j.fact(new ProjectName(projectC, "Brookside Office Park Fit-Out", []));And now we can use that projection to populate a user interface.
const projections = await j.query(projectsWithNamesCreatedByUser, user);
projections.forEach(p => {
console.log(`${p.projectId}: [${p.names.join(", ")}]`);
});| ProjectId | Names |
|---|---|
| 52eb9df8-7b1c-43d4-9cae-710066d54694 | [ "Rivercrest Remodel" ] |
| 967202a9-1b33-442e-820a-624e3a51716b | [ "Pinecrest School Expansion" ] |
| 36b8402a-6993-4f89-aa99-d1ed50ed25f0 | [ "Brookside Office Park Fit-Out" ] |