javascript – 确定位于单元格下方的表列中的单元格

在下表中：

<table>
    <thead>
        <tr>
            <th>Th1</th>
            <th colspan='2'>Th23</th>
            <th>Th4</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>Td1</td>
            <td>Td2</td>
            <td>Td3</td>
            <td>Td4</td>
       </tr>
    </tbody>
</table>

对于包含文本“Th23”的表格单元格,我想知道它下面有哪些单元格.在这种情况下,答案将是分别包含文本“Td2”和“Td3”的单元格.

是否有任何DOM属性或内置函数可以帮助进行此类计算？

@Matt McDonald有一个更通用的解决方案.

这就是我最终得到的结果：

// get tbody cell(s) under thead cell (first arg)
// if rowIndex===undefined, get from all rows; otherwise, only that row index
// NOTE: does NOT work if any cell.rowSpan != 1
var columnCells = function( th, rowIndex ) {
    // get absolute column for th
    for( var absCol=0, i=0; true; i   ) {
            if( th.parentNode.cells[i] == th ) break;
            absCol  = th.parentNode.cells[i].colSpan;
    }
    // look in tBody for cells; all rows or rowIndex
    var tBody = th.parentNode.parentNode.nextSibling;
    var cells = [];
    for( var r=((rowIndex==undefined)?0:rowIndex); true; r   ) {
            if( rowIndex!==undefined && r>rowIndex ) break;
            if( rowIndex==undefined && r>=tBody.rows.length ) break;
            for( var c=0; true; c =tBody.rows[r].cells[c].colSpan ) {
                    if( c < absCol ) continue;
                    if( c >= absCol th.colSpan ) break;
                    cells.push(tBody.rows[r].cells[c]);
            }
    }
    return cells;
}

解决方法:

马上,你需要做三件事：

>为表提供id属性以便于选择.
>为目标单元格提供id属性以便于选择.
>选择单元格的parentNode(行)

这三件事将使表格相关的计算更容易.

Next up是一个抓取指定单元格的伪属性的函数.在这种情况下,我们正在寻找它的“起始索引”(就列而言),它的“结束索引”(就列而言),以及它的“宽度”(结束 – 开始,也在列中).

从那里,您可以遍历表的行并检查哪些单元格位于开始和结束索引之间.

HTML：

<table id="foo">
    <colgroup span="1">
    <colgroup span="2">
    <colgroup span="1">
    <thead>
        <tr>
            <th>foo</th>
            <th id="example" colspan="2">bar</th>
            <th>baz</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>bing</td>
            <td>bang</td>
            <td>boom</td>
            <td>bong</td>
        </tr>
    </tbody>
</table>

JS(跟我一起)：

function getCellSpanProps(table, row, cell)
{
    var isRow = (function()
    {
        var i = 0, currentRow;
        for(i;i<table.rows.length;i  )
        {
            currentRow = table.rows[i];
            if(currentRow === row)
            {
                return true;
            }
            currentRow = null;
        }
        return false;
    }()), 
    cellHasCorrectParent, i = 0, 
    currentCell, colspanCount = 0,
    props;
    if(isRow)
    {
        cellHasCorrectParent = (function()
        {
            return cell.parentNode === row;
        }());
        if(cellHasCorrectParent)
        {
            for(i;i<row.cells.length;i  )
            {
                currentCell = row.cells[i];
                if(currentCell === cell)
                {
                    props = {"start": colspanCount, 
                    "end": colspanCount   cell.colSpan, 
                    "width": (colspanCount   cell.colSpan) - colspanCount};
                    break;
                }
                colspanCount  = currentCell.colSpan;
                currentCell = null;
            }
            row = null;
        }
        return props;
    }
}

function findCellsUnderColumn(table, props)
{
    var i = 0, j = 0, row, cell,
    colspanCount = 0, matches = [],
    blacklist = {"": true, "NaN": true, "null": true, "undefined": true, 
    "false": true};
    if(blacklist[props.start] || blacklist[props.end] || blacklist[props.width])
    {
        return false;
    }
    for(i;i<table.rows.length;i  )
    {
        row = table.rows[i];
        colspanCount = 0;
        for(j=0;j<row.cells.length;j  )
        {
            cell = row.cells[j];
            if(colspanCount >= props.start && colspanCount < props.end)
            {
                matches.push(cell);
            }
            colspanCount  = cell.colSpan;
            cell = null;
        }
        row = null;
    }
    return matches;
}

var table = document.getElementById("foo"), 
example = document.getElementById("example"),
targetRow = example.parentNode,
props = getCellSpanProps(table, targetRow, example),
matches = findCellsUnderColumn(table, props);
console.log(matches);

演示：http:///ohohew/edit#javascript,html

这将确定哪些单元格位于您要查找的特定列中(包括示例).您可以自定义功能以满足您的需求,如果这不是您正在寻找的.

来源：https://www./content-1-313051.html