n8n/packages/nodes-base/nodes/EditImage.node.ts

import {
	BINARY_ENCODING,
	IExecuteSingleFunctions,
} from 'n8n-core';
import {
	IDataObject,
	INodeExecutionData,
	INodeType,
	INodeTypeDescription,
} from 'n8n-workflow';
import * as gm from 'gm';


export class EditImage implements INodeType {
	description: INodeTypeDescription = {
		displayName: 'Edit Image',
		name: 'editImage',
		icon: 'fa:image',
		group: ['transform'],
		version: 1,
		description: 'Edits an image like blur, resize or adding border and text',
		defaults: {
			name: 'Edit Image',
			color: '#553399',
		},
		inputs: ['main'],
		outputs: ['main'],
		properties: [
			{
				displayName: 'Operation',
				name: 'operation',
				type: 'options',
				options: [
					{
						name: 'Blur',
						value: 'blur',
						description: 'Adds a blur to the image and so makes it less sharp',
					},
					{
						name: 'Border',
						value: 'border',
						description: 'Adds a border to the image',
					},
					{
						name: 'Crop',
						value: 'crop',
						description: 'Crops the image',
					},
					{
						name: 'Get Information',
						value: 'information',
						description: 'Returns image information like resolution',
					},
					{
						name: 'Rotate',
						value: 'rotate',
						description: 'Rotate image',
					},
					{
						name: 'Resize',
						value: 'resize',
						description: 'Change the size of image',
					},
					{
						name: 'Text',
						value: 'text',
						description: 'Adds text to image',
					},
				],
				default: 'border',
				description: 'The operation to perform.',
			},

			{
				displayName: 'Property Name',
				name: 'dataPropertyName',
				type: 'string',
				default: 'data',
				description: 'Name of the binary property in which the image data can be found.',
			},


			// ----------------------------------
			//         text
			// ----------------------------------
			{
				displayName: 'Text',
				name: 'text',
				typeOptions: {
					rows: 5,
				},
				type: 'string',
				default: '',
				placeholder: 'Text to render',
				displayOptions: {
					show: {
						operation: [
							'text'
						],
					},
				},
				description: 'Text to write on the image.',
			},
			{
				displayName: 'Font Size',
				name: 'fontSize',
				type: 'number',
				default: 18,
				displayOptions: {
					show: {
						operation: [
							'text'
						],
					},
				},
				description: 'Size of the text.',
			},
			{
				displayName: 'Font Color',
				name: 'fontColor',
				type: 'color',
				default: '#000000',
				displayOptions: {
					show: {
						operation: [
							'text'
						],
					},
				},
				description: 'Color of the text.',
			},
			{
				displayName: 'Position X',
				name: 'positionX',
				type: 'number',
				default: 50,
				displayOptions: {
					show: {
						operation: [
							'text'
						],
					},
				},
				description: 'X (horizontal) position of the text.',
			},
			{
				displayName: 'Position Y',
				name: 'positionY',
				type: 'number',
				default: 50,
				displayOptions: {
					show: {
						operation: [
							'text'
						],
					},
				},
				description: 'Y (vertical) position of the text.',
			},
			{
				displayName: 'Max Line Length',
				name: 'lineLength',
				type: 'number',
				typeOptions: {
					minValue: 1,
				},
				default: 80,
				displayOptions: {
					show: {
						operation: [
							'text'
						],
					},
				},
				description: 'Max amount of characters in a line before a<br />line-break should get added.',
			},


			// ----------------------------------
			//         blur
			// ----------------------------------
			{
				displayName: 'Blur',
				name: 'blur',
				type: 'number',
				typeOptions: {
					minValue: 0,
					maxValue: 1000,
				},
				default: 5,
				displayOptions: {
					show: {
						operation: [
							'blur'
						],
					},
				},
				description: 'How strong the blur should be',
			},
			{
				displayName: 'Sigma',
				name: 'sigma',
				type: 'number',
				typeOptions: {
					minValue: 0,
					maxValue: 1000,
				},
				default: 2,
				displayOptions: {
					show: {
						operation: [
							'blur'
						],
					},
				},
				description: 'The sigma of the blur',
			},


			// ----------------------------------
			//         border
			// ----------------------------------
			{
				displayName: 'Border Width',
				name: 'borderWidth',
				type: 'number',
				default: 10,
				displayOptions: {
					show: {
						operation: [
							'border'
						],
					},
				},
				description: 'The width of the border',
			},
			{
				displayName: 'Border Height',
				name: 'borderHeight',
				type: 'number',
				default: 10,
				displayOptions: {
					show: {
						operation: [
							'border'
						],
					},
				},
				description: 'The height of the border',
			},
			{
				displayName: 'Border Color',
				name: 'borderColor',
				type: 'color',
				default: '#000000',
				displayOptions: {
					show: {
						operation: [
							'border'
						],
					},
				},
				description: 'Color of the border.',
			},


			// ----------------------------------
			//         crop
			// ----------------------------------
			{
				displayName: 'Width',
				name: 'width',
				type: 'number',
				default: 500,
				displayOptions: {
					show: {
						operation: [
							'crop'
						],
					},
				},
				description: 'Crop width',
			},
			{
				displayName: 'Height',
				name: 'height',
				type: 'number',
				default: 500,
				displayOptions: {
					show: {
						operation: [
							'crop'
						],
					},
				},
				description: 'Crop height',
			},
			{
				displayName: 'Position X',
				name: 'positionX',
				type: 'number',
				default: 0,
				displayOptions: {
					show: {
						operation: [
							'crop'
						],
					},
				},
				description: 'X (horizontal) position to crop from.',
			},
			{
				displayName: 'Position Y',
				name: 'positionY',
				type: 'number',
				default: 0,
				displayOptions: {
					show: {
						operation: [
							'crop'
						],
					},
				},
				description: 'Y (vertical) position to crop from.',
			},

			// ----------------------------------
			//         resize
			// ----------------------------------
			{
				displayName: 'Width',
				name: 'width',
				type: 'number',
				default: 500,
				displayOptions: {
					show: {
						operation: [
							'resize'
						],
					},
				},
				description: 'New width of the image',
			},
			{
				displayName: 'Height',
				name: 'height',
				type: 'number',
				default: 500,
				displayOptions: {
					show: {
						operation: [
							'resize'
						],
					},
				},
				description: 'New height of the image',
			},
			{
				displayName: 'Option',
				name: 'resizeOption',
				type: 'options',
				options: [
					{
						name: 'Ignore Aspect Ratio',
						value: 'ignoreAspectRatio',
						description: 'Ignore aspect ratio and resize exactly to specified values',
					},
					{
						name: 'Maximum area',
						value: 'maximumArea',
						description: 'Specified values are maximum area',
					},
					{
						name: 'Minimum Area',
						value: 'minimumArea',
						description: 'Specified values are minimum area',
					},
					{
						name: 'Only if larger',
						value: 'onlyIfLarger',
						description: 'Resize only if image is larger than width or height',
					},
					{
						name: 'Only if smaller',
						value: 'onlyIfSmaller',
						description: 'Resize only if image is smaller than width or height',
					},
				],
				default: 'maximumArea',
				displayOptions: {
					show: {
						operation: [
							'resize'
						],
					},
				},
				description: 'How to resize the image.',
			},

			// ----------------------------------
			//         rotate
			// ----------------------------------
			{
				displayName: 'Rotate',
				name: 'rotate',
				type: 'number',
				typeOptions: {
					minValue: -360,
					maxValue: 360,
				},
				default: 0,
				displayOptions: {
					show: {
						operation: [
							'rotate'
						],
					},
				},
				description: 'How much the image should be rotated',
			},
			{
				displayName: 'Background Color',
				name: 'backgroundColor',
				type: 'color',
				default: '#ffffff',
				displayOptions: {
					show: {
						operation: [
							'rotate'
						],
					},
				},
				description: 'The color to use for the background when image gets rotated by anything which is not a multiple of 90..',
			},
		]
	};


	async executeSingle(this: IExecuteSingleFunctions): Promise<INodeExecutionData> {
		const item = this.getInputData();

		const operation = this.getNodeParameter('operation', 0) as string;
		const dataPropertyName = this.getNodeParameter('dataPropertyName') as string;

		// TODO: Later should make so that it sends directly a valid buffer and the buffer.from stuff is not needed anymore
		if (item.binary === undefined) {
			return item;
		}

		if (item.binary[dataPropertyName as string] === undefined) {
			return item;
		}

		let gmInstance = gm(Buffer.from(item.binary![dataPropertyName as string].data, BINARY_ENCODING));

		if (operation === 'blur') {
			const blur = this.getNodeParameter('blur') as number;
			const sigma = this.getNodeParameter('sigma') as number;
			gmInstance = gmInstance.blur(blur, sigma);
		} else if (operation === 'border') {
			const borderWidth = this.getNodeParameter('borderWidth') as number;
			const borderHeight = this.getNodeParameter('borderHeight') as number;
			const borderColor = this.getNodeParameter('borderColor') as string;

			gmInstance = gmInstance.borderColor(borderColor).border(borderWidth, borderHeight);
		} else if (operation === 'crop')  {
			const width = this.getNodeParameter('width') as number;
			const height = this.getNodeParameter('height') as number;

			const positionX = this.getNodeParameter('positionX') as number;
			const positionY = this.getNodeParameter('positionY') as number;

			gmInstance = gmInstance.crop(width, height, positionX, positionY);
		} else if (operation === 'information')  {
			const imageData = await new Promise<IDataObject>((resolve, reject) => {
				gmInstance = gmInstance.identify((error, imageData) => {
					if (error) {
						reject(error);
						return;
					}
					resolve(imageData as unknown as IDataObject);
				});
			});

			item.json = imageData;
		} else if (operation === 'resize')  {
			const width = this.getNodeParameter('width') as number;
			const height = this.getNodeParameter('height') as number;
			const resizeOption = this.getNodeParameter('resizeOption') as string;

			// By default use "maximumArea"
			let option: gm.ResizeOption = '@';
			if (resizeOption === 'ignoreAspectRatio') {
				option = '!';
			} else if (resizeOption === 'minimumArea') {
				option = '^';
			} else if (resizeOption === 'onlyIfSmaller') {
				option = '<';
			} else if (resizeOption === 'onlyIfLarger') {
				option = '>';
			}

			gmInstance = gmInstance.resize(width, height, option);
		} else if (operation === 'rotate')  {
			const rotate = this.getNodeParameter('rotate') as number;
			const backgroundColor = this.getNodeParameter('backgroundColor') as string;
			gmInstance = gmInstance.rotate(backgroundColor, rotate);
		} else if (operation === 'text') {
			const fontColor = this.getNodeParameter('fontColor') as string;
			const fontSize = this.getNodeParameter('fontSize') as number;
			const lineLength = this.getNodeParameter('lineLength') as number;
			const positionX = this.getNodeParameter('positionX') as number;
			const positionY = this.getNodeParameter('positionY') as number;
			const text = this.getNodeParameter('text') as string || '';

			// Split the text in multiple lines
			const lines: string[] = [];
			let currentLine = '';
			(text as string).split(' ').forEach((textPart: string) => {
				if (currentLine.length + textPart.length + 1 > lineLength) {
					lines.push(currentLine.trim());
					currentLine = `${textPart} `;
					return;
				}
				currentLine += `${textPart} `;
			});
			// Add the last line
			lines.push(currentLine.trim());

			// Combine the lines to a single string
			const renderText = lines.join('\n');

			gmInstance = gmInstance
				.fill(fontColor)
				.fontSize(fontSize)
				.drawText(positionX, positionY, renderText);
		} else {
			throw new Error(`The operation "${operation}" is not supported!`);
		}

		const newItem: INodeExecutionData = {
			json: item.json,
			binary: {},
		};

		if (item.binary !== undefined) {
			// Create a shallow copy of the binary data so that the old
			// data references which do not get changed still stay behind
			// but the incoming data does not get changed.
			Object.assign(newItem.binary, item.binary);
		}

		return new Promise<INodeExecutionData>((resolve, reject) => {
			gmInstance
				.toBuffer((error: Error | null, buffer: Buffer) => {
					if (error) {
						return reject(error);
					}

					newItem.binary![dataPropertyName as string].data = buffer.toString(BINARY_ENCODING);

					return resolve(newItem);
				});
		});
	}
}