ImageDefinition

ImageDefinition is a specialized CoValue designed specifically for managing images in Jazz applications. It extends beyond basic file storage by supporting a blurry placeholder, built-in resizing, and progressive loading patterns.

Beyond ImageDefinition, Jazz offers higher-level functions and components that make it easier to use images:

  • createImage() - function to create an ImageDefinition from a file
  • Image - React component to display a stored image

The Image Upload example demonstrates use of images in Jazz.

Creating Images

The easiest way to create and use images in your Jazz application is with the createImage() function:

import { function createImage(imageBlobOrFile: SourceType, options?: CreateImageOptions): Promise<ImageDefinition>
Creates an ImageDefinition from an image file or blob with built-in UX features. This function creates a specialized CoValue for managing images in Jazz applications. It supports blurry placeholders, built-in resizing, and progressive loading patterns.
@returnsPromise that resolves to an ImageDefinition@example```ts import { createImage } from "jazz-tools/media"; // Create an image from a file input async function handleFileUpload(event: React.ChangeEvent<HTMLInputElement>) { const file = event.target.files?.[0]; if (file) { // Creates ImageDefinition with a blurry placeholder, limited to 1024px // on the longest side, and multiple resolutions automatically const image = await createImage(file, { owner: me._owner, maxSize: 1024, placeholder: "blur", progressive: true, }); // Store the image in your application data me.profile.image = image; } } ```@example```ts // React Native example import { createImage } from "jazz-tools/media"; async function uploadImageFromCamera(imagePath: string) { const image = await createImage(imagePath, { maxSize: 800, placeholder: "blur", progressive: false, }); return image; } ```
createImage
} from "jazz-tools/media";
// Create an image from a file input async function function handleFileUpload(event: React.ChangeEvent<HTMLInputElement>): Promise<void>handleFileUpload(event: React.ChangeEvent<HTMLInputElement>event: export namespace ReactReact.interface React.ChangeEvent<T = Element>ChangeEvent<HTMLInputElement>) { const const file: File | undefinedfile = event: React.ChangeEvent<HTMLInputElement>event.React.ChangeEvent<HTMLInputElement>.target: EventTarget & HTMLInputElementtarget.HTMLInputElement.files: FileList | null
Returns a FileList object on a file type input object. [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLInputElement/files)
files
?.[0];
if (const file: File | undefinedfile) { // Creates ImageDefinition with a blurry placeholder, limited to 1024px on the longest side, and multiple resolutions automatically const
const image: {
    original: FileStream | null;
    originalSize: [number, number];
    placeholderDataURL: string | undefined;
    progressive: boolean;
} & {
    [key: string]: FileStream | null;
} & CoMap
image
= await function createImage(imageBlobOrFile: SourceType, options?: CreateImageOptions): Promise<ImageDefinition>
Creates an ImageDefinition from an image file or blob with built-in UX features. This function creates a specialized CoValue for managing images in Jazz applications. It supports blurry placeholders, built-in resizing, and progressive loading patterns.
@returnsPromise that resolves to an ImageDefinition@example```ts import { createImage } from "jazz-tools/media"; // Create an image from a file input async function handleFileUpload(event: React.ChangeEvent<HTMLInputElement>) { const file = event.target.files?.[0]; if (file) { // Creates ImageDefinition with a blurry placeholder, limited to 1024px // on the longest side, and multiple resolutions automatically const image = await createImage(file, { owner: me._owner, maxSize: 1024, placeholder: "blur", progressive: true, }); // Store the image in your application data me.profile.image = image; } } ```@example```ts // React Native example import { createImage } from "jazz-tools/media"; async function uploadImageFromCamera(imagePath: string) { const image = await createImage(imagePath, { maxSize: 800, placeholder: "blur", progressive: false, }); return image; } ```
createImage
(const file: Filefile, {
owner?: Account | Group | undefined
The owner of the image. Can be either a Group or Account. If not specified, the current user will be the owner.
owner
:
const me: {
    _owner: Account | Group;
    profile: {
        image: ImageDefinition;
    };
}
me
._owner: Account | Group_owner,
maxSize?: number | undefined
Maximum size constraint for the image. The image will be resized to fit within this size while maintaining aspect ratio. If the image is smaller than maxSize in both dimensions, no resizing occurs.
@example1024 // Resizes image to fit within 1024px in the largest dimension
maxSize
: 1024,
placeholder?: false | "blur" | undefined
Controls placeholder generation for the image. - `"blur"`: Generates a blurred placeholder image (default) - `false`: No placeholder is generated
@default"blur"
placeholder
: "blur",
progressive?: boolean | undefined
The progressive loading pattern is a technique that allows images to load incrementally, starting with a small version and gradually replacing it with a larger version as it becomes available. This is useful for improving the user experience by showing a placeholder while the image is loading. Passing progressive: true to createImage() will create internal smaller versions of the image for future uses.
@defaultfalse
progressive
: true,
}); // Store the image in your application data
const me: {
    _owner: Account | Group;
    profile: {
        image: ImageDefinition;
    };
}
me
.
profile: {
    image: ImageDefinition;
}
profile
.
image: {
    original: FileStream | null;
    originalSize: [number, number];
    placeholderDataURL: string | undefined;
    progressive: boolean;
} & {
    [key: string]: FileStream | null;
} & CoMap
image
=
const image: {
    original: FileStream | null;
    originalSize: [number, number];
    placeholderDataURL: string | undefined;
    progressive: boolean;
} & {
    [key: string]: FileStream | null;
} & CoMap
image
;
} }

Note: createImage() currently supports browser and react-native environments.

The createImage() function:

  • Creates an ImageDefinition with the right properties
  • Generates a small placeholder for immediate display
  • Creates multiple resolution variants of your image
  • Returns the created ImageDefinition

Configuration Options

import type { ImageDefinition, Group, Account } from "jazz-tools";
// ---cut---
declare function createImage(
  image: Blob | File | string,
  options: {
    owner?: Group | Account;
    placeholder?: "blur" | false;
    maxSize?: number;
    progressive?: boolean;
  }): Promise<ImageDefinition>

image

The image to create an ImageDefinition from. On browser environments, this can be a Blob or a File. On React Native, this must be a string with the file path.

owner

The owner of the ImageDefinition. This is used to control access to the image. See Groups as permission scopes for more information on how to use groups to control access to images.

placeholder

Sometimes the wanted image is not loaded yet. The placeholder is a base64 encoded image that is displayed while the image is loading. Currently, only "blur" is a supported.

maxSize

The image generation process includes a maximum size setting that controls the longest side of the image. A built-in resizing feature is applied based on this setting.

progressive

The progressive loading pattern is a technique that allows images to load incrementally, starting with a small version and gradually replacing it with a larger version as it becomes available. This is useful for improving the user experience by showing a placeholder while the image is loading.

Passing progressive: true to createImage() will create internal smaller versions of the image for future uses.

Create multiple resized copies

To create multiple resized copies of an original image for better layout control, you can utilize the createImage function multiple times with different parameters for each desired size. Here’s an example of how you might implement this:

import { import coco } from "jazz-tools";
import { function createImage(imageBlobOrFile: SourceType, options?: CreateImageOptions): Promise<ImageDefinition>
Creates an ImageDefinition from an image file or blob with built-in UX features. This function creates a specialized CoValue for managing images in Jazz applications. It supports blurry placeholders, built-in resizing, and progressive loading patterns.
@returnsPromise that resolves to an ImageDefinition@example```ts import { createImage } from "jazz-tools/media"; // Create an image from a file input async function handleFileUpload(event: React.ChangeEvent<HTMLInputElement>) { const file = event.target.files?.[0]; if (file) { // Creates ImageDefinition with a blurry placeholder, limited to 1024px // on the longest side, and multiple resolutions automatically const image = await createImage(file, { owner: me._owner, maxSize: 1024, placeholder: "blur", progressive: true, }); // Store the image in your application data me.profile.image = image; } } ```@example```ts // React Native example import { createImage } from "jazz-tools/media"; async function uploadImageFromCamera(imagePath: string) { const image = await createImage(imagePath, { maxSize: 800, placeholder: "blur", progressive: false, }); return image; } ```
createImage
} from "jazz-tools/media";
// Jazz Schema const
const ProductImage: co.Map<{
    image: co.Map<{
        original: import("/vercel/path0/packages/jazz-tools/dist/tools/internal").FileStreamSchema;
        originalSize: ZodTuple<[ZodNumber, ZodNumber], null>;
        placeholderDataURL: ZodOptional<ZodString>;
        progressive: ZodBoolean;
    }, co.FileStream, Account | Group>;
    thumbnail: co.Map<...>;
}, unknown, Account | Group>
ProductImage
= import coco.
map<{
    image: co.Map<{
        original: import("/vercel/path0/packages/jazz-tools/dist/tools/internal").FileStreamSchema;
        originalSize: ZodTuple<[ZodNumber, ZodNumber], null>;
        placeholderDataURL: ZodOptional<ZodString>;
        progressive: ZodBoolean;
    }, co.FileStream, Account | Group>;
    thumbnail: co.Map<...>;
}>(shape: {
    image: co.Map<{
        original: import("/vercel/path0/packages/jazz-tools/dist/tools/internal").FileStreamSchema;
        originalSize: ZodTuple<[ZodNumber, ZodNumber], null>;
        placeholderDataURL: ZodOptional<ZodString>;
        progressive: ZodBoolean;
    }, co.FileStream, Account | Group>;
    thumbnail: co.Map<...>;
}): co.Map<...>
export map
map
({
image: co.Map<{
    original: import("/vercel/path0/packages/jazz-tools/dist/tools/internal").FileStreamSchema;
    originalSize: ZodTuple<[ZodNumber, ZodNumber], null>;
    placeholderDataURL: ZodOptional<ZodString>;
    progressive: ZodBoolean;
}, co.FileStream, Account | Group>
image
: import coco.
function image(): co.Image
export image
image
(),
thumbnail: co.Map<{
    original: import("/vercel/path0/packages/jazz-tools/dist/tools/internal").FileStreamSchema;
    originalSize: ZodTuple<[ZodNumber, ZodNumber], null>;
    placeholderDataURL: ZodOptional<ZodString>;
    progressive: ZodBoolean;
}, co.FileStream, Account | Group>
thumbnail
: import coco.
function image(): co.Image
export image
image
(),
}); const
const mainImage: {
    original: FileStream | null;
    originalSize: [number, number];
    placeholderDataURL: string | undefined;
    progressive: boolean;
} & {
    [key: string]: FileStream | null;
} & CoMap
mainImage
= await function createImage(imageBlobOrFile: SourceType, options?: CreateImageOptions): Promise<ImageDefinition>
Creates an ImageDefinition from an image file or blob with built-in UX features. This function creates a specialized CoValue for managing images in Jazz applications. It supports blurry placeholders, built-in resizing, and progressive loading patterns.
@returnsPromise that resolves to an ImageDefinition@example```ts import { createImage } from "jazz-tools/media"; // Create an image from a file input async function handleFileUpload(event: React.ChangeEvent<HTMLInputElement>) { const file = event.target.files?.[0]; if (file) { // Creates ImageDefinition with a blurry placeholder, limited to 1024px // on the longest side, and multiple resolutions automatically const image = await createImage(file, { owner: me._owner, maxSize: 1024, placeholder: "blur", progressive: true, }); // Store the image in your application data me.profile.image = image; } } ```@example```ts // React Native example import { createImage } from "jazz-tools/media"; async function uploadImageFromCamera(imagePath: string) { const image = await createImage(imagePath, { maxSize: 800, placeholder: "blur", progressive: false, }); return image; } ```
createImage
(const myBlob: BlobmyBlob);
const
const thumbnail: {
    original: FileStream | null;
    originalSize: [number, number];
    placeholderDataURL: string | undefined;
    progressive: boolean;
} & {
    [key: string]: FileStream | null;
} & CoMap
thumbnail
= await function createImage(imageBlobOrFile: SourceType, options?: CreateImageOptions): Promise<ImageDefinition>
Creates an ImageDefinition from an image file or blob with built-in UX features. This function creates a specialized CoValue for managing images in Jazz applications. It supports blurry placeholders, built-in resizing, and progressive loading patterns.
@returnsPromise that resolves to an ImageDefinition@example```ts import { createImage } from "jazz-tools/media"; // Create an image from a file input async function handleFileUpload(event: React.ChangeEvent<HTMLInputElement>) { const file = event.target.files?.[0]; if (file) { // Creates ImageDefinition with a blurry placeholder, limited to 1024px // on the longest side, and multiple resolutions automatically const image = await createImage(file, { owner: me._owner, maxSize: 1024, placeholder: "blur", progressive: true, }); // Store the image in your application data me.profile.image = image; } } ```@example```ts // React Native example import { createImage } from "jazz-tools/media"; async function uploadImageFromCamera(imagePath: string) { const image = await createImage(imagePath, { maxSize: 800, placeholder: "blur", progressive: false, }); return image; } ```
createImage
(const myBlob: BlobmyBlob, {
maxSize?: number | undefined
Maximum size constraint for the image. The image will be resized to fit within this size while maintaining aspect ratio. If the image is smaller than maxSize in both dimensions, no resizing occurs.
@example1024 // Resizes image to fit within 1024px in the largest dimension
maxSize
: 100,
}); // or, in case of migration, you can use the original stored image. const
const newThumb: {
    original: FileStream | null;
    originalSize: [number, number];
    placeholderDataURL: string | undefined;
    progressive: boolean;
} & {
    [key: string]: FileStream | null;
} & CoMap
newThumb
= await function createImage(imageBlobOrFile: SourceType, options?: CreateImageOptions): Promise<ImageDefinition>
Creates an ImageDefinition from an image file or blob with built-in UX features. This function creates a specialized CoValue for managing images in Jazz applications. It supports blurry placeholders, built-in resizing, and progressive loading patterns.
@returnsPromise that resolves to an ImageDefinition@example```ts import { createImage } from "jazz-tools/media"; // Create an image from a file input async function handleFileUpload(event: React.ChangeEvent<HTMLInputElement>) { const file = event.target.files?.[0]; if (file) { // Creates ImageDefinition with a blurry placeholder, limited to 1024px // on the longest side, and multiple resolutions automatically const image = await createImage(file, { owner: me._owner, maxSize: 1024, placeholder: "blur", progressive: true, }); // Store the image in your application data me.profile.image = image; } } ```@example```ts // React Native example import { createImage } from "jazz-tools/media"; async function uploadImageFromCamera(imagePath: string) { const image = await createImage(imagePath, { maxSize: 800, placeholder: "blur", progressive: false, }); return image; } ```
createImage
(
const mainImage: {
    original: FileStream | null;
    originalSize: [number, number];
    placeholderDataURL: string | undefined;
    progressive: boolean;
} & {
    [key: string]: FileStream | null;
} & CoMap
mainImage
!.original: FileStream | nulloriginal!.
FileStream.toBlob(options?: {
    allowUnfinished?: boolean;
}): Blob | undefined
toBlob
()!, {
maxSize?: number | undefined
Maximum size constraint for the image. The image will be resized to fit within this size while maintaining aspect ratio. If the image is smaller than maxSize in both dimensions, no resizing occurs.
@example1024 // Resizes image to fit within 1024px in the largest dimension
maxSize
: 100,
}); const
const imageSet: {
    image: {
        original: FileStream;
        originalSize: [number, number];
        placeholderDataURL: string | undefined;
        progressive: boolean;
    } & {
        [key: string]: FileStream;
    } & CoMap;
    thumbnail: {
        original: FileStream;
        originalSize: [number, number];
        placeholderDataURL: string | undefined;
        progressive: boolean;
    } & ... 1 more ... & CoMap;
} & CoMap
imageSet
=
const ProductImage: co.Map<{
    image: co.Map<{
        original: import("/vercel/path0/packages/jazz-tools/dist/tools/internal").FileStreamSchema;
        originalSize: ZodTuple<[ZodNumber, ZodNumber], null>;
        placeholderDataURL: ZodOptional<ZodString>;
        progressive: ZodBoolean;
    }, co.FileStream, Account | Group>;
    thumbnail: co.Map<...>;
}, unknown, Account | Group>
ProductImage
.
CoMapSchema<{ image: CoMapSchema<{ original: import("/vercel/path0/packages/jazz-tools/dist/tools/internal").FileStreamSchema; originalSize: ZodTuple<[ZodNumber, ZodNumber], null>; placeholderDataURL: ZodOptional<ZodString>; progressive: ZodBoolean; }, FileStreamSchema, Account | Group>; thumbnail: CoMapSchema<...>; }, unknown, Account | Group>.create: (init: {
    image: ({
        original: FileStream | null;
        originalSize: [number, number];
        placeholderDataURL: string | undefined;
        progressive: boolean;
    } & {
        [key: string]: FileStream | null;
    } & CoMap) | {
        ...;
    };
    thumbnail: ({
        original: FileStream | null;
        originalSize: [number, number];
        placeholderDataURL: string | undefined;
        progressive: boolean;
    } & ... 1 more ... & CoMap) | {
        ...;
    };
}, options?: Account | ... 2 more ... | undefined) => {
    ...;
} & CoMap
create
({
image: ({
    original: FileStream | null;
    originalSize: [number, number];
    placeholderDataURL: string | undefined;
    progressive: boolean;
} & {
    [key: string]: FileStream | null;
} & CoMap) | {
    ...;
}
image
:
const mainImage: {
    original: FileStream | null;
    originalSize: [number, number];
    placeholderDataURL: string | undefined;
    progressive: boolean;
} & {
    [key: string]: FileStream | null;
} & CoMap
mainImage
,
thumbnail: ({
    original: FileStream | null;
    originalSize: [number, number];
    placeholderDataURL: string | undefined;
    progressive: boolean;
} & {
    [key: string]: FileStream | null;
} & CoMap) | {
    ...;
}
thumbnail
,
});

Displaying Images

To use the stored ImageDefinition, there are two ways: the Image react component, and the helpers functions.

<Image> component

The Image component is the best way to let Jazz handle the image loading.

import * as React from "react";
import { co } from "jazz-tools";
const ImageDef = co.image();
// ---cut---
import { Image } from "jazz-tools/react";

function GalleryView({ image }: { image: co.loaded<typeof ImageDef> }) {
  return (
    <div className="image-container">
      <Image imageId={image.id} alt="Profile" width={600} />
    </div>
  );
}

The Image component handles:

  • Showing a placeholder while loading, if generated
  • Automatically selecting the appropriate resolution, if generated with progressive loading
  • Progressive enhancement as higher resolutions become available, if generated with progressive loading
  • Determining the correct width/height attributes to avoid layout shifting
  • Cleaning up resources when unmounted

The component's props are:

export type ImageProps = Omit<
  JSX.IntrinsicElements["img"],
  "src" | "srcSet" | "width" | "height"
> & {
  imageId: string;
  width?: number | "original";
  height?: number | "original";
};

Width and Height props

The width and height props are used to control the best resolution to use but also the width and height attributes of the image tag.

Let's say we have an image with a width of 1920px and a height of 1080px.

<Image imageId="123" />
// <img src={...} /> with the highest resolution available

<Image imageId="123" width="original" height="original" />
// <img width="1920" height="1080" />

<Image imageId="123" width="600" />
// <img width="600" /> leaving the browser to compute the height (might cause layout shift)

<Image imageId="123" width="600" height="original" />
// <img width="600" height="338" /> keeping the aspect ratio

<Image imageId="123" width="original" height="600" />
// <img width="1067" height="600" /> keeping the aspect ratio

<Image imageId="123" width="600" height="600" />
// <img width="600" height="600" />

If the image was generated with progressive loading, the width and height props will determine the best resolution to use.

Lazy loading

The Image component supports lazy loading based on browser's strategy. It will generate the blob url for the image when the browser's viewport reaches the image.

<Image imageId="123" width="original" height="original" loading="lazy" />

Imperative usage

Like other CoValues, ImageDefinition can be used to load the object.

import { 
type ImageDefinition = {
    original: FileStream | null;
    originalSize: [number, number];
    placeholderDataURL: string | undefined;
    progressive: boolean;
} & {
    [key: string]: FileStream | null;
} & CoMap
const ImageDefinition: CoMapSchema<{
    original: import("/vercel/path0/packages/jazz-tools/dist/tools/internal").FileStreamSchema;
    originalSize: ZodTuple<[ZodNumber, ZodNumber], null>;
    placeholderDataURL: ZodOptional<ZodString>;
    progressive: ZodBoolean;
}, FileStreamSchema, Account | Group>
@categoryMedia
ImageDefinition
} from "jazz-tools";
const
const image: CoMapLikeLoaded<{
    original: FileStream | null;
    originalSize: [number, number];
    placeholderDataURL: string | undefined;
    progressive: boolean;
} & CoMap, {
    original: true;
}, 10, []> | null
image
= await
const ImageDefinition: CoMapSchema<{
    original: import("/vercel/path0/packages/jazz-tools/dist/tools/internal").FileStreamSchema;
    originalSize: ZodTuple<[ZodNumber, ZodNumber], null>;
    placeholderDataURL: ZodOptional<ZodString>;
    progressive: ZodBoolean;
}, FileStreamSchema, Account | Group>
@categoryMedia
ImageDefinition
.
CoMapSchema<{ original: import("/vercel/path0/packages/jazz-tools/dist/tools/internal").FileStreamSchema; originalSize: ZodTuple<[ZodNumber, ZodNumber], null>; placeholderDataURL: ZodOptional<ZodString>; progressive: ZodBoolean; }, FileStreamSchema, Account | Group>.load<{
    original: true;
}>(id: string, options?: {
    resolve?: RefsToResolve<{
        original: FileStream | null;
        originalSize: [number, number];
        placeholderDataURL: string | undefined;
        progressive: boolean;
    } & CoMap, 10, []> | undefined;
    loadAs?: Account | AnonymousJazzAgent;
    skipRetry?: boolean;
} | undefined): Promise<...>
load
("123", {
resolve?: RefsToResolve<{
    original: FileStream | null;
    originalSize: [number, number];
    placeholderDataURL: string | undefined;
    progressive: boolean;
} & CoMap, 10, []> | undefined
resolve
: {
original?: RefsToResolve<FileStream, 10, [0]> | undefinedoriginal: true, }, }); if(
const image: CoMapLikeLoaded<{
    original: FileStream | null;
    originalSize: [number, number];
    placeholderDataURL: string | undefined;
    progressive: boolean;
} & CoMap, {
    original: true;
}, 10, []> | null
image
) {
var console: Console
The `console` module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers. The module exports two specific components: * A `Console` class with methods such as `console.log()`, `console.error()` and `console.warn()` that can be used to write to any Node.js stream. * A global `console` instance configured to write to [`process.stdout`](https://nodejs.org/docs/latest-v20.x/api/process.html#processstdout) and [`process.stderr`](https://nodejs.org/docs/latest-v20.x/api/process.html#processstderr). The global `console` can be used without importing the `node:console` module. _**Warning**_: The global console object's methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the [`note on process I/O`](https://nodejs.org/docs/latest-v20.x/api/process.html#a-note-on-process-io) for more information. Example using the global `console`: ```js console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3 const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr ``` Example using the `Console` class: ```js const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err); myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err ```
@see[source](https://github.com/nodejs/node/blob/v20.11.1/lib/console.js)
console
.Console.log(message?: any, ...optionalParams: any[]): void (+2 overloads)
[MDN Reference](https://developer.mozilla.org/docs/Web/API/console/log_static)
log
({
originalSize: [number, number]originalSize:
const image: CoMapLikeLoaded<{
    original: FileStream | null;
    originalSize: [number, number];
    placeholderDataURL: string | undefined;
    progressive: boolean;
} & CoMap, {
    original: true;
}, 10, []>
image
.originalSize: [number, number]originalSize,
placeholderDataUrl: string | undefinedplaceholderDataUrl:
const image: CoMapLikeLoaded<{
    original: FileStream | null;
    originalSize: [number, number];
    placeholderDataURL: string | undefined;
    progressive: boolean;
} & CoMap, {
    original: true;
}, 10, []>
image
.placeholderDataURL: string | undefinedplaceholderDataURL,
original: FileStreamoriginal:
const image: CoMapLikeLoaded<{
    original: FileStream | null;
    originalSize: [number, number];
    placeholderDataURL: string | undefined;
    progressive: boolean;
} & CoMap, {
    original: true;
}, 10, []>
image
.original: FileStreamoriginal, // this FileStream may be not loaded yet
}); }

image.original is a FileStream and its content can be read as described in the FileStream documentation.

Since FileStream objects are also CoValues, they must be loaded before use. To simplify loading, if you want to load the binary data saved as Original, you can use the loadImage function.

import { 
function loadImage(imageOrId: ImageDefinition | string): Promise<{
    width: number;
    height: number;
    image: FileStream;
} | null>
loadImage
} from "jazz-tools/media";
const
const image: {
    width: number;
    height: number;
    image: FileStream;
} | null
image
= await
function loadImage(imageOrId: ImageDefinition | string): Promise<{
    width: number;
    height: number;
    image: FileStream;
} | null>
loadImage
(const imageDefinitionOrId: stringimageDefinitionOrId);
if(
const image: {
    width: number;
    height: number;
    image: FileStream;
} | null
image
) {
var console: Console
The `console` module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers. The module exports two specific components: * A `Console` class with methods such as `console.log()`, `console.error()` and `console.warn()` that can be used to write to any Node.js stream. * A global `console` instance configured to write to [`process.stdout`](https://nodejs.org/docs/latest-v20.x/api/process.html#processstdout) and [`process.stderr`](https://nodejs.org/docs/latest-v20.x/api/process.html#processstderr). The global `console` can be used without importing the `node:console` module. _**Warning**_: The global console object's methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the [`note on process I/O`](https://nodejs.org/docs/latest-v20.x/api/process.html#a-note-on-process-io) for more information. Example using the global `console`: ```js console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3 const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr ``` Example using the `Console` class: ```js const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err); myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err ```
@see[source](https://github.com/nodejs/node/blob/v20.11.1/lib/console.js)
console
.Console.log(message?: any, ...optionalParams: any[]): void (+2 overloads)
[MDN Reference](https://developer.mozilla.org/docs/Web/API/console/log_static)
log
({
width: numberwidth:
const image: {
    width: number;
    height: number;
    image: FileStream;
}
image
.width: numberwidth,
height: numberheight:
const image: {
    width: number;
    height: number;
    image: FileStream;
}
image
.height: numberheight,
image: FileStreamimage:
const image: {
    width: number;
    height: number;
    image: FileStream;
}
image
.image: FileStreamimage,
}); }

If the image was generated with progressive loading, and you want to access the best-fit resolution, use loadImageBySize. It will load the image of the best resolution that fits the wanted width and height.

import { 
function loadImageBySize(imageOrId: ImageDefinition | string, wantedWidth: number, wantedHeight: number): Promise<{
    width: number;
    height: number;
    image: FileStream;
} | null>
loadImageBySize
} from "jazz-tools/media";
const
const image: {
    width: number;
    height: number;
    image: FileStream;
} | null
image
= await
function loadImageBySize(imageOrId: ImageDefinition | string, wantedWidth: number, wantedHeight: number): Promise<{
    width: number;
    height: number;
    image: FileStream;
} | null>
loadImageBySize
(const imageDefinitionOrId: stringimageDefinitionOrId, 600, 600); // 600x600
if(
const image: {
    width: number;
    height: number;
    image: FileStream;
} | null
image
) {
var console: Console
The `console` module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers. The module exports two specific components: * A `Console` class with methods such as `console.log()`, `console.error()` and `console.warn()` that can be used to write to any Node.js stream. * A global `console` instance configured to write to [`process.stdout`](https://nodejs.org/docs/latest-v20.x/api/process.html#processstdout) and [`process.stderr`](https://nodejs.org/docs/latest-v20.x/api/process.html#processstderr). The global `console` can be used without importing the `node:console` module. _**Warning**_: The global console object's methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the [`note on process I/O`](https://nodejs.org/docs/latest-v20.x/api/process.html#a-note-on-process-io) for more information. Example using the global `console`: ```js console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3 const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr ``` Example using the `Console` class: ```js const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err); myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err ```
@see[source](https://github.com/nodejs/node/blob/v20.11.1/lib/console.js)
console
.Console.log(message?: any, ...optionalParams: any[]): void (+2 overloads)
[MDN Reference](https://developer.mozilla.org/docs/Web/API/console/log_static)
log
({
width: numberwidth:
const image: {
    width: number;
    height: number;
    image: FileStream;
}
image
.width: numberwidth,
height: numberheight:
const image: {
    width: number;
    height: number;
    image: FileStream;
}
image
.height: numberheight,
image: FileStreamimage:
const image: {
    width: number;
    height: number;
    image: FileStream;
}
image
.image: FileStreamimage,
}); }

If want to dynamically listen to the loaded resolution that best fits the wanted width and height, you can use the subscribe and the highestResAvailable function.

import { ImageDefinition } from "jazz-tools";
// ---cut---
// function highestResAvailable(image: ImageDefinition, wantedWidth: number, wantedHeight: number): FileStream | null
import { highestResAvailable } from "jazz-tools/media";

const image = await ImageDefinition.load("123");

image?.subscribe({}, (image) => {
  const bestImage = highestResAvailable(image, 600, 600);

  if(bestImage) {
    // bestImage is again a FileStream
    const blob = bestImage.image.toBlob();
    if(blob) {
      const url = URL.createObjectURL(blob);
      // ...
    }
  }
});

Image manipulation custom implementation

To manipulate the images (like placeholders, resizing, etc.), createImage() uses different implementations depending on the environment. Currently, the image manipulation is supported on browser and react-native environments.

On the browser, the image manipulation is done using the canvas API. If you want to use a custom implementation, you can use the createImageFactory function in order create your own createImage function and use your preferred image manipulation library.

import { createImageFactory } from "jazz-tools/media";

const createImage = createImageFactory({
    createFileStreamFromSource: async (source, owner) => {
        // ...
    },
    getImageSize: async (image) => {
        // ...
    },
    getPlaceholderBase64: async (image) => {
        // ...
    },
    resize: async (image, width, height) => {
        // ...
    },
});