@latel88/message v1.2.5

Stream

how to use

• install

npm install @latel88/stream

• CJS

const { Stream, Pipe } = require( "@latel88/stream" ).default;

• ESM

import { Stream, Pipe } from "@latel88/stream";

exsample

• how to use stream class.

class FileStream extends Stream
{
    constructor ( src, type = "text" )
    {
        super( ( resolve, reject ) =>
        {
            const xhr = new XMLHttpRequest();

            xhr.onreadystatechange = () =>
            {
                if (xhr.readyState === 4)
                {
                    if ((200 <= xhr.status && xhr.status < 300) || (xhr.status === 304))
                    {
                        const source = xhr.response;
                        
                        resolve( source );

                    }
                    else
                    {
                        reject( new Error( `File not found. ${ url }` ) );

                    }

                }

            };

            xhr.onerror = () =>
            {
                reject( new Error( `File not found. ${ url }` ) );

            };

            xhr.open( "GET", src, true );
            xhr.responseType = type;
            xhr.send( null );

        } );

    }

}

• how to use pipe class.

class ToImagePipe extends Pipe
{
	constructor ()
	{
		super( ( data, resolve, reject ) =>
		{
			const source = new Image();
				
			source.onload = () => resolve( source );
			source.onerror = () => reject( new Error( "Can not process image." ) );

			switch (true)
			{
				case typeof( data.source ) === "string":
					source.src = `data:image/jpeg;base64,${ data.source }`;
					break;

				case data.source instanceof Blob:
					source.src = window.URL.createObjectURL( data.source );
					break;

				case data.source instanceof ArrayBuffer:
					const bytes = new Uint8Array( data.source );

					let binaryData = "";

					for (let i = 0, len = bytes.byteLength; i < len; i++)
					{
						binaryData += String.fromCharCode( bytes[ i ] );

					}

					source.src = `data:image/jpeg;base64,${ window.btoa( binaryData ) }`;
					break;

			}

		} );

	}

}

new FileStream( "anonymous.png" ).pipe( new ToImagePipe() ).then( ( event ) =>
{
	const image = event.data;

}, ( event ) =>
{
	const error = event.data;

	throw error;

} );