I need to download the created pixel drawing from this Phaser example as a .png image via FilesSaver.js but the canvas returns null.
Error:
Uncaught TypeError: Cannot read properties of null (reading 'toBlob')
This is the save function:
function save() {
var canvasX = document.getElementById("canvas");
canvasX.toBlob(function(blob) { saveAs(blob, "image.png"); }); }
drawingArea: (PhaserJS 2)
function createDrawingArea() {
game.create.grid('drawingGrid', 16 * canvasZoom, 16 * canvasZoom, canvasZoom, canvasZoom, 'rgba(0,191,243,0.8)');
canvas = game.make.bitmapData(spriteWidth * canvasZoom, spriteHeight * canvasZoom);
canvasBG = game.make.bitmapData(canvas.width + 2, canvas.height + 2);
canvasBG.rect(0, 0, canvasBG.width, canvasBG.height, '#fff');
canvasBG.rect(1, 1, canvasBG.width - 2, canvasBG.height - 2, '#3f5c67');
var x = 10;
var y = 64;
canvasBG.addToWorld(x, y);
canvasSprite = canvas.addToWorld(x + 1, y + 1);
canvasGrid = game.add.sprite(x + 1, y + 1, 'drawingGrid');
canvasGrid.crop(new Phaser.Rectangle(0, 0, spriteWidth * canvasZoom, spriteHeight * canvasZoom));
}
How to get the data of the drawing to create a .png out of it?
Well I don't think the canvas has the ID canvas. That's why, I asume that is the reason for the null Error.
In any case I took the original example code, as a basis for this working solution.
Disclaimer: This Code will only create a image from the "drawn-image", not the whole UI.
Main idea, On Save:
canvasfilesave.jsInfo: I'm getting information/values from the the globally defined variables canvasGrid and canvas, if your code, doesn't contain them, this code will not work.
I hope this helps.
function saveImage() {
// I assume there will be only one canvas on the page
let realCanvas = document.querySelector('canvas');
let ouputCanvas = document.createElement('canvas');
let ctx = ouputCanvas.getContext('2d');
// Get the target area (Details are from example code)
let xOfGrid = canvasGrid.x - 1; // Info from Linie 267 from example
let yOfGrid = canvasGrid.y - 1; // Info from Linie 267 from example
// Info: this "canvas" is not a HTML Canvas Element
let width = canvas.width; // Info from Linie 256 from example
let height = canvas.height; // Info from Linie 256 from example
// Set initial Canvas Size
ouputCanvas.width = width;
ouputCanvas.height = height;
// draw Image onto new Canvas
ctx.drawImage(realCanvas, xOfGrid, yOfGrid, width, height, 0, 0, width, height);
// Output Image, with filesaver.js
ouputCanvas.toBlob(function onDone(blob) {
saveAs(blob, "image.png");
});
}
// An extra "Save Button", for testing
window.addEventListener('DOMContentLoaded', function(){
let btn = document.createElement('button');
btn.innerText = 'SAVE FILE';
btn.addEventListener('click', saveImage);
document.body.prepend( btn );
});