Question

我有一个大的数据表，大致如下。如下所述，这是一个完整的样本，而不是简化。

<table class="grid resultRaceGrid" id="mainGrid">
<tr>
    <th width="10">&nbsp;</th>
    <th>&nbsp;</th>
    <th>&nbsp;</th>
    <th>HORSE/SP</th>
    <th>AGE</th>
    <th>WGT</th>
    <th>TRAINER/JOCKEY</th>
    <th>OR</th>
    <th>TS</th>
    <th>RPR</th>
    <th width="10">&nbsp;</th>
</tr>
<tr>
    <td colspan="11" class="separator">&nbsp;</td>
</tr>
<tr>
    <td rowspan="2" class="last"><a href="/horses/result_home.sd?race_id=443557&amp;r_date=2007-11-21&amp;popup=yes" class="bull"><b>&laquo;</b></a></td>
    <td rowspan="2" class="nowrap noPad"><h3>1 </h3></td>
    <td rowspan="2" class="dstDesc"></td>
    <td class="nowrap"><span class="black"><a href="#" id="noteIcon_673823" class="pencil" onclick="return false;"><!-- --></a><b><a href="/horses/horse_home.sd?horse_id=673823" onclick="return popup(this, {width:695, height:800})" title="Full details about this HORSE">Andytown</a></b> (IRE) 6/4F <img src="http://ui.racingpost.com/ico/tipping-success.gif" class="shilda" title="Tipped by Topspeed" alt="" /></span></td>
    <td class="black">5</td>
    <td class="nowrap black"><span>11-1&nbsp;<span class="lightGray"></span></span></td>
    <td class="nowrap black"><a href="/horses/trainer_home.sd?trainer_id=13176" onclick="return popup(this, {width:695, height:800})" title="Full details about this TRAINER">N G Richards</a></td>
    <td rowspan="2" class="lightGray">&mdash;</td>
    <td rowspan="2" class="lightGray"><span class="red bold">*</span></td>
    <td rowspan="2" class="last"><span class="red bold">*</span></td>
    <td rowspan="2" class="last"><a href="/horses/result_home.sd?race_id=450083&amp;r_date=2008-03-08&amp;popup=yes" class="bull"><b>&raquo;</b></a></td>
</tr>
<tr>
    <td colspan="3"><span class="pedigrees">ch g <a href="/bloodstock/stallionbook/stallion_home.sd?horse_id=42337&amp;popup=1" onclick="return popup(this, {width:734, height:800})" title="Full details about this STALLION">Old Vic</a> - <a href="/bloodstock/dam_home.sd?horse_id=519458" onclick="return popup(this, {width:695, height:800})" title="Full details about this DAM ">Pitfire (IRE)</a> (<a href="/bloodstock/stallionbook/stallion_home.sd?horse_id=303796&amp;popup=1" onclick="return popup(this, {width:734, height:800})" title="Full details about this STALLION">Parliament</a>)</span></td>
    <td class="lightGray"><a href="/horses/jockey_home.sd?jockey_id=82320" onclick="return popup(this, {width:695, height:800})" title="Full details about this JOCKEY">Fearghal Davis</a><sup>5</sup></td>
</tr>
<tr class="rowComment hideComment">
    <td colspan="3">&nbsp;</td>
    <td colspan="7"><div class="commentText">   Went prominent 6th, challenged 2 out, soon ridden, narrow advantage last, forged clear towards finish (tchd 7-4)</div></td>
    <td>&nbsp;</td>
</tr>
<tr>
    <td colspan="11" class="separator">&nbsp;</td>
</tr>

我有以下XPath，它允许我正确匹配整行感兴趣。

我的问题是：如何选择此tr以及以下两个tr元素（跟随它）。

$xpath->query("//table[@id='mainGrid']//tr[descendant::a[contains(@href,'horse_home')]]"

Answer 1

使用：

//table[@id='mainGrid'] //tr[descendant::a [contains(@href,'horse_home')] ] | //table[@id='mainGrid'] //tr[descendant::a [contains(@href,'horse_home')] ] /following-sibling::tr[not(position() > 2)]

此XPath表达式优化了您之前的选择，指定应该选择它与最多两个tr兄弟姐妹（之前选择的tr元素）之间的联合。

Answer 2

只是为了好玩，没有两个绝对表达式的结合：

//table[@id='mainGrid'] 
   //tr[(self::tr|preceding-sibling::tr[not(position() > 2)])
              [descendant::a 
                  [contains(@href,'horse_home')] 
              ]
       ]

作为证明，假设这减少了输入样本：

<table id="mainGrid">
    <tr>1</tr>
    <tr>2</tr>
    <tr>3</tr>
    <tr>
        <a href="/horses/horse_home.sd"/>
    </tr>
    <tr>5</tr>
    <tr>6</tr>
    <tr>7</tr>
    <tr>
        <a href="/horses/horse_home.sd"/>
    </tr>
    <tr>8</tr>
    <tr>9</tr>
    <tr>10</tr>
</table>

此样式表：

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output indent="yes"/>
<xsl:template match="/">
  <xsl:copy-of select="
//table[@id='mainGrid']
   //tr[(self::tr|preceding-sibling::tr[not(position() > 2)])
              [descendant::a
                  [contains(@href,'horse_home')]
              ]
       ]
"/>
</xsl:template>
</xsl:stylesheet>

输出：

<tr>
    <a href="/horses/horse_home.sd" />
</tr>
<tr>5</tr>
<tr>6</tr>
<tr>
    <a href="/horses/horse_home.sd" />
</tr>
<tr>8</tr>
<tr>9</tr>

Answer 3

$xpath->query("//table[@id='mainGrid']//tr[descendant::a[contains(@href,'horse_home')] | //table[@id='mainGrid']//tr[descendant::a[contains(@href,'horse_home')]/following-sibling::tr[position() < 3]"是一种方式（我认为效率不高）。

使用XPath 2.0（您的PHP API可能不支持），您可以使用$xpath->query("//table[@id='mainGrid']//tr[descendant::a[contains(@href,'horse_home')]/(., following-sibling::tr[position() < 3])。

Answer 4

那么你一定要考虑使用Xpath轴。 following-sibling和previous-sibling

那么你的表达应该是这样的：

$xpath->query("//table[@id='mainGrid']/tr[descendant::a[contains(@href,'horse_home')]/following-sibling::tr[2]")

XPath选择元素和后续元素

4 个答案: