What's the Reactive way to collapse elements into an array? - json

Question

Take the following TypeScript/Angular 2 code sample:
query(): Rx.Observable<any> {
return Observable.create((o) => {
var refinedPosts = new Array<RefinedPost>();
var observable = this.server.get('http://localhost/rawData.json').toRx().concatMap(
result =>
result.json().posts
)
.map((post: any) => {
// Assume I want to convert the raw JSON data into a nice class object with
// methods, etc.
var refinedPost = new RefinedPost();
refinedPost.Message = post.Message.toLowerCase();
refinedPosts.push(refinedPost);
})
.subscribeOnCompleted(() => {
o.onNext(refinedPosts);
})
});
}
Written out, the database is returning JSON. I want to iterate over the raw JSON and create a custom object, eventually returning to subscribers an Array<RefinedPost>.
The code works and the final subscribers get what they need, but I can't help but feel like I didn't do it the "Reactive Way". I cheated and used an external accumulator to gather up the elements in the Array, which seems to defeat the purpose of using streams.
So, the question is, is there a better, more concise, reactive way to write this code?

Answer 1

Answering my own question.
query(): Rx.Observable<any> {
return this.server.get('http://localhost/rawData.json').toRx().concatMap(
result =>
result.json().posts
)
.map((post: any) => {
var refinedPost = new RefinedPost();
refinedPost.Message = post.Message.toLowerCase();
return refinedPost;
}).toArray();
}
This removes the internal accumulator and the wrapped Observable. toArray() took the sequence of items and brought them together into an array.