Question

我需要通过PHP DOMDocument

获取所有页面段落和所有列表项的所有父项。

比方说，我们有这样的html：

<div>
    <p>Some text</p>
    <p>Some text</p>
</div>
<section>
    <p>Some text</p>
    <p>Some text</p>
    <p>Some text</p>
</section>
<ul>
    <li>Item 1</li>
    <li>Item 2</li>
    <li>Item 3</li>
    <li>Item 4</li>
</ul>

如果我使用以下两个循环

$parents = [];
foreach($dom->getElementsByTagName('p') as $paragraph) {
    $parents[] = $paragraph->parentNode;
}
foreach($dom->getElementsByTagName('li') as $li) {
    $parents[] = $li->parentNode;
}

最后，我只需要向每个父母添加一个类

foreach($parents as $key => $parent) {
     $parent->setAttribute('class', 'prefix_'.$key);
}

，并希望获得输出

<div class="prefix_0">
...
</div>
<section class="prefix_1">
...
</section>
<div class="prefix_2">
...
</div>

但是我明白了

<div class="prefix_0 prefix_1">
...
</div>
<section class="prefix_2 prefix_3 prefix_4">
...
</section>
<div class="prefix_5 prefix_6 prefix_7 prefix_8">
...
</div>

如果我添加条件

if(!in_array($paragraph->parentNode, $parents)) {

它不起作用，因为我们没有数组，而是节点列表

那么如何避免添加相同的父代？

Answer 1

非常简单地避免发生这种情况：

by(final_df, final_df$symbol, head)

# final_df$symbol: CNI
#              Date  Open  High   Low Close Adj..Close    Volume symbol
# 998  Feb 08, 2018 76.08 76.16 74.11 74.45      72.79 1,508,100    CNI
# 999  Feb 07, 2018 76.86 77.23 76.01 76.17      74.48 1,645,400    CNI
# 1000 Feb 06, 2018 76.21 77.42 74.81 77.14      75.42 2,293,300    CNI
# 1001 Feb 05, 2018 78.00 78.70 77.12 77.17      75.45 1,711,000    CNI
# 1002 Feb 02, 2018 79.17 79.24 78.17 78.46      76.71 1,331,400    CNI
# 1003 Feb 01, 2018 79.91 80.54 79.24 79.82      78.04 1,231,500    CNI
# ------------------------------------------------------------------------------ 
# final_df$symbol: CSX
#             Date  Open  High   Low Close Adj..Close     Volume symbol
# 333 Feb 08, 2018 52.91 53.16 50.46 50.47      49.80  7,798,100    CSX
# 334 Feb 07, 2018 53.38 54.36 52.94 52.97      52.26  6,496,200    CSX
# 335 Feb 06, 2018 51.27 54.00 50.12 53.82      53.10 10,563,700    CSX
# 336 Feb 05, 2018 54.89 55.04 51.96 51.99      51.30  9,070,200    CSX
# 337 Feb 02, 2018 56.19 56.35 55.20 55.25      54.51  9,275,800    CSX
# 338 Feb 01, 2018 56.10 57.10 56.04 56.58      55.83  4,079,100    CSX
# ------------------------------------------------------------------------------ 
# final_df$symbol: KSU
#              Date   Open   High    Low  Close Adj..Close    Volume symbol
# 1330 Feb 08, 2018 107.17 107.64 103.50 103.53     102.15 1,434,600    KSU
# 1331 Feb 07, 2018 106.59 108.27 106.59 107.10     105.67 1,326,800    KSU
# 1332 Feb 06, 2018 103.11 108.02 102.07 107.32     105.89 1,459,400    KSU
# 1333 Feb 05, 2018 109.73 110.44 105.12 105.18     103.77 1,272,100    KSU
# 1334 Feb 02, 2018 112.06 112.85 110.03 110.15     108.68 1,051,900    KSU
# 1335 Feb 01, 2018 112.80 114.00 112.17 112.87     111.36 1,011,200    KSU
# ------------------------------------------------------------------------------ 
# final_df$symbol: NSC
#             Date   Open   High    Low  Close Adj..Close    Volume symbol
# 665 Feb 08, 2018 142.62 143.27 136.87 136.89     134.22 2,657,200    NSC
# 666 Feb 07, 2018 142.09 144.45 141.37 142.68     139.89 1,464,500    NSC
# 667 Feb 06, 2018 136.99 143.45 134.55 143.05     140.26 2,455,000    NSC
# 668 Feb 05, 2018 144.74 146.73 138.18 138.61     135.90 2,508,900    NSC
# 669 Feb 02, 2018 147.15 147.85 144.61 145.03     142.20 1,774,600    NSC
# 670 Feb 01, 2018 149.28 150.35 147.90 148.47     145.57 1,427,000    NSC
# ------------------------------------------------------------------------------ 
# final_df$symbol: UNP
#           Date   Open   High    Low  Close Adj..Close     Volume symbol
# 1 Feb 08, 2018 128.70 128.70 124.81 124.86     122.27  6,325,100    UNP
# 2 Feb 07, 2018 130.34 131.82 128.94 128.96     126.29  5,053,000    UNP
# 3 Feb 06, 2018 122.28 131.50 121.50 131.15     128.43 15,734,300    UNP
# 4 Feb 05, 2018 128.59 131.78 124.13 124.14     121.57  6,744,400    UNP
# 5 Feb 02, 2018 131.66 131.73 127.22 129.36     126.68  8,181,200    UNP
# 6 Feb 01, 2018 132.51 133.74 131.86 132.38     129.64  5,597,600    UNP

使用：

function compareParentNode($compare_node,$parents){
   foreach($parents as $parent){
       if ($parent->isSameNode($compare_node)) return true;
   }
   return false;
}

查看更多isSameNode

如何检查dom节点列表是否已具有相同的节点

1 个答案: