element中el-table(合计)计算指定列

想要某列展示合计数值的
<el-table
:data="tableData"
style="width: 100%"
:header-cell-style="{ background: '#F8F9FB' }"
:summary-method="getSummaries"
show-summary
>
<el-table-column align="center" label="余额" min-width="100" prop="money">
<template slot-scope="{ row }">
{{ row.money || '-' }}
</template>
</el-table-column>
</el-table>
getSummaries(param) {
const { columns, data } = param
const sums = []
columns.forEach((column, index) => {
if (index === 0) {
sums[index] = '合计'
return
} else if (index === 3 || index === 4) {
const values = data.map(item => Number(item[column.property]))
if (!values.every(value => isNaN(value))) {
sums[index] = values.reduce((prev, curr) => {
const value = Number(curr)
if (!isNaN(value)) {
return prev + curr
} else {
return prev
}
}, 0)
switch (column.property) {
case 'total1':
case 'total2':
case 'total3':
return (sums[index] = sums[index])
break
}
} else {
sums[index] = ''
}
} else {
}
})
return sums
},