【js-xlsx和file-saver插件】前端html的table导出数据到excel的表格增加表格标题行

基于上一篇随笔后，新需求需要再导出的表格上面加一行标题行

function parse_dom_table_addtitle(table, _opts, title) {
        var opts = _opts || {};
        var oss = opts.defaultCellStyle || {};  /*单元格样式  */
        if (DENSE != null) opts.dense = DENSE;
        var ws = opts.dense ? ([]) : ({});
        var rows = table.getElementsByTagName('tr');
        var sheetRows = Math.min(opts.sheetRows || 10000000, rows.length);
        var range = { s: { r: 0, c: 0 }, e: { r: sheetRows+1 , c: 0 } };
        var merges = [], midx = 0;
        var R = 1, _C = 0, C = 0, RS = 0, CS = 0;
        var _title = title || ""; 
        var title_o = { t: 's', v: _title, s: oss };
        ws[encode_cell({ c: 0, r: 0 })] = title_o;
        var maxc = 0;
        for (; R < sheetRows+1; ++R) {
            var nR = R - 1
            var row = rows[nR];
            var elts = (row.children);
            for (_C = C = 0; _C < elts.length; ++_C) {
                var elt = elts[_C], v = htmldecode(elts[_C].innerHTML);
                for (midx = 0; midx < merges.length; ++midx) {
                    var m = merges[midx];
                    if (m.s.c == C && m.s.r <= R && R <= m.e.r) {
                        C = m.e.c + 1; midx = -1;
                    }
                }
                /* TODO: figure out how to extract nonstandard mso- style */
                CS = +elt.getAttribute("colspan") || 1;
                if ((RS = +elt.getAttribute("rowspan")) > 0 || CS > 1)
                    merges.push({ s: { r: R, c: C }, e: { r: R + (RS || 1) - 1, c: C + CS - 1 } });
                var o = { t: 's', v: v, s: oss };
                var _t = elt.getAttribute("t") || "";
                if (v != null) {
                    if (v.length == 0) o.t = _t || 's';
                    else if (opts.raw || v.trim().length == 0 || _t == "s") { }
                    else if (v === 'TRUE') o = { t: 'b', v: true, s: oss };
                    else if (v === 'FALSE') o = { t: 'b', v: false, s: oss };
                    else if (!isNaN(fuzzynum(v))) o = { t: 'n', v: fuzzynum(v), s: oss };
                    else if (!isNaN(fuzzydate(v).getDate())) {
                        o = ({ t: 'd', v: parseDate(v), s: oss });
                        if (!opts.cellDates) o = ({ t: 'n', v: datenum(o.v), s: oss });
                        o.z = opts.dateNF || SSF._table[14];
                    }
                }
                if (opts.dense) { if (!ws[R]) ws[R] = []; ws[R][C] = o; }
                else ws[encode_cell({ c: C, r: R })] = o;
                /* 合并数据处理开始*/
                if (CS > 1) {
                    for (var i = 1; i < CS; i++) {
                        var newc = C + i
                        if (RS > 1) {
                            for (var m = 1; m < RS; m++) {
                                var newr = R + m;
                                ws[encode_cell({ c: newc, r: newr })] = o;
                            }
                        }
                        else {
                            ws[encode_cell({ c: newc, r: R })] = o;
                        }
                    }
                }
                else {
                    if (RS > 1) {
                        for (var m = 1; m < RS; m++) {
                            var newr = R + m;
                            ws[encode_cell({ c: C, r: newr })] = o;
                        }
                    }
                    else {
                        ws[encode_cell({ c: C, r: R })] = o;
                    }
                }
                /*合并数据处理结束*/
                if (range.e.c < C) range.e.c = C;
                C += CS;
                if (maxc < C)
                {
                    maxc = C;
                }
            }
            if (R == sheetRows)
            {
                merges.push({ s: { r: 0, c: 0 }, e: { r: 0, c: maxc-1 } });
            }
        }
        ws['!merges'] = merges;
        ws['!ref'] = encode_range(range);
        if (sheetRows < rows.length) ws['!fullref'] = encode_range((range.e.r = rows.length-1 , range));
        return ws;
    }