@paroi/media-engine
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    0.5.4 • Public • Published

    @paroi/media-engine

    A backend library to upload and store files in SQLite, then to serve them.

    How to create a MediaStorage

    The MediaStorage stores the files in a relational database. It resizes images in the configured dimensions.

    Open a connection with LADC using the adapter for SQLite and the integration with the query builder SQL Bricks:

    npm install @paroi/media-engine ladc @ladc/sqlite3-adapter @ladc/sql-bricks-modifier
    import ladc from "ladc"
    import sqlite3Adapter from "@ladc/sqlite3-adapter"
    import sqlBricksModifier from "@ladc/sql-bricks-modifier"
    
    let cn = ladc({
      adapter: sqlite3Adapter({ fileName: "path/to/db.sqlite" }),
      modifier: sqlBricksModifier()
    }

    Then, create the storage:

    export async function createStorage(cn: import("@ladc/sql-bricks-modifier").SBMainConnection, execDdl: boolean) {
      return await createMediaStorage({
        execInitScript: execDdl ? "sqlite" : undefined,
        cn,
        imagesConf: IMAGES_CONF
      })
    }
    
    const IMAGES_CONF: import("@paroi/media-engine").ImageVariantsConfiguration = {
      "imageType1": [
        {
          code: "34x34",
          width: 68,
          height: 68,
          mediaType: "image/png"
        },
        {
          code: "200x200",
          width: 200,
          height: 200,
          mediaType: "image/jpeg"
        }
      ],
      "imageType2": [
        {
          code: "200x100",
          width: 200,
          height: 100,
          embed: true,
          mediaType: "image/jpeg"
        }
      ]
    }

    Notice: The MediaStorage can be used without an UploadEngine.

    How to create an UploadEngine

    The UploadEngine declares and implements the routes to express.

    Here is how to create an UploadEngine:

    import { Request } from "express"
    import { ExternalRef, MediaRef, Media, MulterFile, MediaStorage, createMediaStorage, isSupportedImage } from "@paroi/media-engine"
    import { createUploadEngine, UploadEngine, UploadEngineManager } from "@paroi/media-engine/upload"
    
    export async function createUpload(storage: MediaStorage) {
      return createUploadEngine({
        manager: createUploadEngineManager(storage),
        storage,
        baseUrl: `url/to/medias`
      })
    }
    
    function createUploadEngineManager(storage: MediaStorage): UploadEngineManager {
      return {
        canUpload(req: Request, externalRef: ExternalRef, overwrite: boolean, file: MulterFile) {
          return {
            canUpload: true,
            ownerId: "123"
          }
        },
    
        async makeJsonResponseForUpload(req: Request, mediaId: string, overwritten: boolean) {
          return { /* your JSON response */ }
        },
    
        canRead(req: Request, mediaRef: MediaRef) {
          return true
        },
    
        canDelete(req: Request, mediaRef: MediaRef) {
          return true
        },
    
        async makeJsonResponseForDelete(req: Request, deletedMedia: Media) {
          return { /* your JSON response */ }
        }
      }
    }

    Then, let it declare the routes:

    const express = require("express")
    
    let router = express.Router()
    uploadEngine.declareRoutes(router)
    
    let app = express()
    app.use(router)
    let server = http.createServer(app)
    server.listen(8080)

    Now, three routes are available:

    • url/to/medias/upload (POST) Upload a file and create a media. A JSON object of type UploadedFile must be sent as a parameter with the file.
    • url/to/medias/delete (POST) Delete a media. A JSON object of type { mediaId: string } must be sent as a request body.
    • url/to/medias/:year/:variantId/:fileName?download=1 (GET) Serve a file. An optional URL parameter download can be set.

    The UploadedFile type:

    interface UploadedFile {
      ref {
        type: string
        id: string
      }
      overwrite?: boolean
    }

    Install

    npm i @paroi/media-engine

    DownloadsWeekly Downloads

    2

    Version

    0.5.4

    License

    CC0-1.0

    Unpacked Size

    78.7 kB

    Total Files

    31

    Last publish

    Collaborators

    • rickfaf
    • paleo