odata-v4-server/src/example/stream.ts

OData V4 Server

import * as fs from "fs";
import * as path from "path";
import { Writable } from "stream";
import { MongoClient, Db, ObjectID } from "mongodb";
import { createQuery, createFilter } from "odata-v4-mongodb";
import { Readable, PassThrough } from "stream";
import { ODataServer, ODataController, Edm, odata, ODataStream, ODataQuery, ODataHttpContext } from "../lib";
import { Category, Product } from "./model";
import { createMetadataJSON } from "../lib/metadata";

const mongodb = async function():Promise<Db>{
    return (await MongoClient.connect("mongodb://localhost:27017/odataserver")).db();
};

const delay = async function(ms:number):Promise<any>{
    return new Promise(resolve => setTimeout(resolve, ms));
};

@odata.type(Product)
class ProductsController extends ODataController{
    /*@odata.GET
    *find(@odata.query query:ODataQuery, @odata.stream stream:Writable):any{
        let db:Db = yield mongodb();
        let mongodbQuery = createQuery(query);
        if (typeof mongodbQuery.query._id == "string") mongodbQuery.query._id = new ObjectID(mongodbQuery.query._id);
        if (typeof mongodbQuery.query.CategoryId == "string") mongodbQuery.query.CategoryId = new ObjectID(mongodbQuery.query.CategoryId);
        return db.collection("Products")
            .find(
                mongodbQuery.query,
                mongodbQuery.projection,
                mongodbQuery.skip,
                mongodbQuery.limit
            ).stream().pipe(stream);
    }*/
    // example using generator with mongodb .next() and passing entity data into OData stream
    @odata.GET
    *find(@odata.query query:ODataQuery, @odata.stream stream:Writable){
        let db:Db = yield mongodb();
        let mongodbQuery = createQuery(query);
        if (typeof mongodbQuery.query._id == "string") mongodbQuery.query._id = new ObjectID(mongodbQuery.query._id);
        if (typeof mongodbQuery.query.CategoryId == "string") mongodbQuery.query.CategoryId = new ObjectID(mongodbQuery.query.CategoryId);
        let cursor = db.collection("Products")
            .find(
                mongodbQuery.query, {
                    projection: mongodbQuery.projection,
                    skip: mongodbQuery.skip,
                    limit: mongodbQuery.limit
                }
            );
        let item = yield cursor.next();
        while (item){
            stream.write(item);
            item = yield cursor.next();
        }
        stream.end();
    }

    @odata.GET
    *findOne(@odata.key() key:string, @odata.query query:ODataQuery){
        let db:Db = yield mongodb();
        let mongodbQuery = createQuery(query);
        return db.collection("Products").findOne({ _id: new ObjectID(key) }, {
            fields: mongodbQuery.projection
        });
    }

    @odata.POST
    async insert(@odata.body data:any){
        let db = await mongodb();
        if (data.CategoryId) data.CategoryId = new ObjectID(data.CategoryId);
        return await db.collection("Products").insert(data).then((result) => {
            data._id = result.insertedId;
            return data;
        });
    }
}

@odata.type(Category)
class CategoriesController extends ODataController{
    @odata.GET
    *find(@odata.query query:ODataQuery):any{
        let db:Db = yield mongodb();
        let mongodbQuery = createQuery(query);
        if (typeof mongodbQuery.query._id == "string") mongodbQuery.query._id = new ObjectID(mongodbQuery.query._id);
        let cursor = db.collection("Categories")
            .find(
                mongodbQuery.query, {
                    projection: mongodbQuery.projection,
                    skip: mongodbQuery.skip,
                    limit: mongodbQuery.limit
                }
            );
        let result = yield cursor.toArray();
        result.inlinecount = yield cursor.count(false);
        return result;
    }

    @odata.GET
    *findOne(@odata.key() key:string, @odata.query query:ODataQuery){
        let db:Db = yield mongodb();
        let mongodbQuery = createQuery(query);
        return db.collection("Categories").findOne({ _id: new ObjectID(key) }, {
            fields: mongodbQuery.projection
        });
    }
}

enum Genre{
    Unknown,
    Pop,
    Rock,
    Metal,
    Classic
}

@Edm.MediaEntity("audio/mp3")
class Music extends PassThrough{
    @Edm.Key
    @Edm.Computed
    @Edm.TypeDefinition(ObjectID)
    //@Edm.Int32
    Id:ObjectID

    @Edm.String
    Artist:string

    @Edm.String
    Title:string

    @Edm.EnumType(Genre)
    Genre:Genre

    @Edm.TypeDefinition(ObjectID)
    uid:ObjectID
}

@odata.namespace("NorthwindTypes")
class NorthwindTypes extends Edm.ContainerBase{
    @Edm.Flags
    @Edm.Int64
    @Edm.Serialize(value => `NorthwindTypes.Genre2'${value}'`)
    Genre2 = Genre

    @Edm.String
    @Edm.URLDeserialize((value:string) => new Promise(resolve => setTimeout(_ => resolve(new ObjectID(value)), 1000)))
    @Edm.Deserialize(value => new ObjectID(value))
    ObjectID2 = ObjectID

    Music2 = Music
}

@odata.type(Music)
@odata.container("Media")
class MusicController extends ODataController{
    @odata.GET
    find(@odata.filter filter:ODataQuery, @odata.query query:ODataQuery){
        console.log(JSON.stringify(createQuery(query).query, null, 2), JSON.stringify(createFilter(filter), null, 2));
        let music = new Music();
        music.Id = new ObjectID;
        music.Artist = "Dream Theater";
        music.Title = "Six degrees of inner turbulence";
        music.Genre = Genre.Metal;
        music.uid = new ObjectID();
        return [music];
    }

    @odata.GET
    findOne(@odata.key() _:number){
        let music = new Music();
        music.Id = new ObjectID;
        music.Artist = "Dream Theater";
        music.Title = "Six degrees of inner turbulence";
        music.Genre = Genre.Metal;
        music.uid = new ObjectID();
        return music;
    }

    @odata.POST
    insert(@odata.body body: Music){
        body.Id = new ObjectID();
        console.log(body);
        return body;
    }

    @odata.GET.$value
    mp3(@odata.key _:number, @odata.context context:ODataHttpContext){
        let file = fs.createReadStream("tmp.mp3");
        return new Promise((resolve, reject) => {
            file.on("open", () => {
                context.response.on("finish", () => {
                    file.close();
                });
                resolve(file);
            }).on("error", reject);
        });
    }

    @odata.POST.$value
    post(@odata.key _:number, @odata.body upload:Readable){
        let file = fs.createWriteStream("tmp.mp3");
        return new Promise((resolve, reject) => {
            file.on('open', () => {
                upload.pipe(file);
            }).on('error', reject);
            upload.on('end', resolve);
        });
    }
}

class ImageMember{
    @Edm.String
    value:string
}

@Edm.OpenType
class Image{
    @Edm.Key
    @Edm.Computed
    @Edm.Int32
    Id:number

    @Edm.String
    Filename:string

    @Edm.Collection(Edm.ComplexType(ImageMember))
    Members:ImageMember[]

    @Edm.Stream("image/png")
    Data:ODataStream

    @Edm.Stream("image/png")
    Data2:ODataStream
}

@odata.type(Image)
@odata.container("Media")
class ImagesController extends ODataController{
    @odata.GET
    images(@odata.key id:number){
        let image = new Image();
        image.Id = id;
        image.Filename = "tmp.png";
        (<any>image).mm = [[1,2],[3,4]];
        return image;
    }

    @odata.GET("Members")
    *getMembers(@odata.key _:number, @odata.stream stream:Writable){
        for (let i = 0; i < 10; i++){
            stream.write({ value: `Member #${i}` });
            yield delay(1);
        }
        stream.end();
    }

    @odata.GET("Data")
    @odata.GET("Data2").$value
    getData(@odata.key _:number, @odata.context context:ODataHttpContext, @odata.result result: Image){
        return new ODataStream(fs.createReadStream(result.Filename)).pipe(context.response);
    }

    @odata.POST("Data")
    @odata.POST("Data2").$value
    postData(@odata.key _:number, @odata.body data:Readable, @odata.result result: Image){
        return new ODataStream(fs.createWriteStream(result.Filename)).write(data);
    }
}

@Edm.OpenType
class PlainObject{}

@Edm.Container(NorthwindTypes)
@odata.controller(ProductsController, true)
@odata.controller(CategoriesController, true)
@odata.controller(MusicController, true)
@odata.controller(ImagesController, true)
class StreamServer extends ODataServer{
    @Edm.TypeDefinition(ObjectID)
    @Edm.FunctionImport
    objid(@Edm.TypeDefinition(ObjectID) v:ObjectID){
        return v.toHexString();
    }

    @Edm.FunctionImport(Edm.String)
    stringify(@Edm.EntityType(PlainObject) obj:any):string {
        return JSON.stringify(obj);
    }

    @odata.container("almafa")
    @Edm.FunctionImport(Edm.Stream)
    async Fetch(@Edm.String filename:string, @odata.stream stream:Writable, @odata.context context:any){
        let file = fs.createReadStream(filename);
        return file.on("open", () => {
            context.response.contentType(path.extname(filename));
            file.pipe(stream);
        });
    }
}
//console.dir(createMetadataJSON(StreamServer).dataServices.schema[0]["function"][1].parameter);
//console.log(createMetadataJSON(StreamServer).dataServices.schema[0].entityType[2]);
//console.log(StreamServer.$metadata().edmx.dataServices.schemas[0].typeDefinitions);
StreamServer.create("/odata", 3000);