VCard Implementtaion in Javascript

VCard.class.js

// See: https://www.rfc-editor.org/rfc/rfc6350

class VCard{

	constructor(){
		this.kind = null;
		this.name = [];
		this.nickname = [];
		this.photo = [];
		this.bday = null;
		this.anniversary = null;
		this.gender = null;
		this.gender_ident = null;
		this.address = [];
	}

	// see: .rfc6350 3.2 line delimiting and formatting
	formatTextValue(str){
		var chars = [...str];
		var max_line_bytes = 75;
		var lines = [];
		var curr_line = [];
		var curr_line_bytes = 0;
		for (let i = 0; i < chars.length; i++) {
		  var char = chars[i];
		  if(char === ',') char = '\,';
		  if(char === "\n") char = '\\n';
		  var char_bytes = new Blob([char]).size;
		  if(curr_line_bytes + char_bytes > max_line_bytes){
			lines.push(curr_line.join(''));
			curr_line = [' ', char];
			curr_line_bytes = 1 + char_bytes;
		  }else{
			curr_line.push(char);
			curr_line_bytes += char_bytes;
		  }
		}
		lines.push(curr_line.join(''));
		return lines.join("\n");
	}

	formatDate(date){
		var [y, m, d, h, min, sec, ms] = date.toISOString().split(/[^\d]+/);
		return `${y}${m}${d}T${h}${min}${sec}Z`;
	}

	imgToDataURI(img){
		var image = new Image();
		image.crossOrigin = 'Anonymous';
		image.onload = ()=>{
			var canvas = document.createElement('canvas');
			var context = canvas.getContext('2d');
			canvas.height = image.naturalHeight;
			canvas.width = image.naturalWidth;
			context.drawImage(image, 0, 0);
			done(canvas.toDataURL('image/jpeg'));
		};
		image.src = img.src;
	}

	setNickname(nickname){
		this.nickname.push(nickname);
		return this;
	}

	setName(name){
		this.name.push(name);
		return this;
	}

	setKind(kind){
		kind = kind.trim().toLowerCase();
		let allowed_values = [
			VCard.KIND_IND,
			VCard.KIND_GRP,
			VCard.KIND_ORG,
			VCard.KIND_LOC
		];
		if(!allowed_values.includes(kind)){
			throw new Error("Invalid Kind value.");
		}
		this.kind = kind;
		return this;
	}

	setPhoto(img){
		if(!(img instanceof Image)){
			throw new Error('Invalid Image.');
		}
		this.photo.push(img);
		return this;
	}

	setBday(bday){
		if(!(bday instanceof Date)){
			throw new Error("Invalid Birthday date");
		}
		this.bday = bday;
		return this;
	}

	setAnniversary(anniversary){
		if(!(anniversary instanceof Date)){
			throw new Error("Invalid Anniversary date");
		}
		this.anniversary = anniversary;
		return this;
	}

	setGender(gender, ident=null){
		gender = gender.trim().toLowerCase();
		if(ident) ident = ident.trim().toLowerCase();
		let allowed_values = [
			VCard.GENDER_MAL,
			VCard.GENDER_FEM,
			VCard.GENDER_OTH,
			VCard.GENDER_NON,
			VCard.GENDER_UNK
		];
		if(!allowed_values.includes(gender)){
			throw new Error("Invalid Gender value.");
		}
		this.gender = gender;
		this.gender_ident = ident;
		return this;
	}

	setAddress(){

	}

	async render(){
		if(!this.name.length){
			throw new Error("Missing Name property.");
		}

		var parts = [];
		parts.push('BEGIN:VCARD');
		parts.push('VERSION:4.0');

		if(this.kind){
			parts.push(`KIND:${this.kind}`);
		}

		for(let i=0; i<this.name.length; i++){
			parts.push(this.formatTextValue(`FN:${this.name[i]}`));
		}

		if(this.nickname.length){
			parts.push(`NICKNAME:${this.formatTextValue(this.nickname.join(','))}`);
		}

		for(let i=0; i<this.photo.length; i++){
			let photo = await this.imgToDataURI(this.photo[i]);
			parts.push(this.formatTextValue(`PHOTO:${photo}`));
		}

		if(this.bday){
			parts.push(this.formatDate(`BDAY:${this.bday}`));
		}

		if(this.anniversary){
			parts.push(this.formatDate(`ANNIVERSARY:${this.anniversary}`));
		}
		
		if(this.gender){
			let gender = this.gender;
			if(this.gender_ident) gender += `;${this.gender_ident}`;
			parts.push(this.formatTextValue(`GENDER:${gender}`));
		}



		parts.push('END:VCARD');
	}
}

VCard.KIND_IND = 'individual';
VCard.KIND_GRP = 'group';
VCard.KIND_ORG = 'org';
VCard.KIND_LOC = 'location';

VCard.GENDER_MAL = 'M';
VCard.GENDER_FEM = 'F';
VCard.GENDER_OTH = 'O';
VCard.GENDER_NON = 'N';
VCard.GENDER_UNK = 'U';