Export to CSV + File download via JS

download_CSV.ts

public csvData<T>(arr: T[], keys: Array<{ field: string, title?: string}> = []): string {
            //MD EXPORT
            //CONVERTE ARRAY DATI -> CSV CON PRIMA RIGA NOME CAMPI
            const sep = ";";
            if (arr && arr.length) {
                if (keys == null || keys.length == 0) keys = Object.keys(arr[0]).map(k => ({ field: k, title: k }));
                const titles = keys.map(key => key.title || key.field);
                let csv = arr.map(obj => {
                    let row: string[] = [];
                    keys.forEach(key => {
                        let v = key.field.split(".").reduce((obj,k)=>obj && obj[k], obj);
                        if (v == null) row.push("");
                        else if (typeof v == "string") row.push(`"${v.replace('"', '""')}"`);
                        else row.push(`${v}`);
                    });
                    return row.join(sep);
                })
                //let head = Object.keys(obj).join(sep); csv.unshift(head);
                csv.unshift(titles.join(sep));
                return csv.join("\n");
            } else return "NO DATA TO EXPORT";
        }

        public downloadFile(data: any, name: string = "storico.csv") {
            //MD EXPORT
            //SOURCE CODE PRESO DA www.youtube.com/watch?v=io2blfAlO6E
            const blob = new Blob([data], { type: "octet-stream" }); //application/octet-stream
            const href = URL.createObjectURL(blob);
            this.startDownload(href, name);
            URL.revokeObjectURL(href);
            //a.remove();
        }

        public startDownload(href: string, name: string) {
            // @ts-ignore
            const a: HTMLAnchorElement = Object.assign(document.createElement("a"), {
                href,
                style: "display:none",
                download: name
            });
            document.body.appendChild(a);
            a.click();
            a.remove();
        }