Question

这可能只是一个语法问题。

我不清楚如何仅匹配id以rowId _

开头的表行

agent = Mechanize.new
  pageC1 = agent.get("/customStrategyScreener!list.action")

该表有class = tableCellDT。

 pageC1.search('table.tableCellDT tr[@id=rowId_]')  # parses OK but returns 0 rows since rowId_ is not matched exactly.

 pageC1.search('table.tableCellDT tr[@id=rowId_*]')  # Throws an error since * is not treated like a wildcard string match

示例HTML：

 <table id="row" cellpadding="5" class="tableCellDT" cellspacing="1">
<thead>
<tr>
<th class="tableHeaderDT">#</th>
<th class="tableHeaderDT sortable">
<a href="?d-16544-s=1&amp;d-16544-o=2&amp;d-16544-p=1">Screener</a></th>
<th class="tableHeaderDT sortable">
<a href="?d-16544-s=2&amp;d-16544-o=2&amp;d-16544-p=1">Strategy</a></th>
<th class="tableHeaderDT"> </th></tr></thead>
<tbody>
<tr id="rowId_BullPut" class="odd">
<td>   1  </td>
<td>   Bull</td>
<td></td>
<td><a href="link1?model.itemId=2262">Edit</a>&nbsp;&nbsp;
            <a href="javascript:deleteScreener('link2?model.itemId=2262');">Delete</a>&nbsp;&nbsp;
            <a href="link3?model.itemId=2262&amp;amp;model.source=list">View</a>&nbsp;&nbsp;
            </td></tr>

请注意

pageC1 是Mechanize::Page个对象，而不是Nokogiri任何内容。抱歉，一开始并不清楚。 Mechanize :: Page没有#css或#xpath方法，但可以从中提取Nokogiri doc（无论如何在内部使用）。

Answer 1

要获取tr元素，其中id以“rowId _”开头：

pageC1.search('//tr[starts-with(@id, "rowId_")]')

Answer 2

你想要CSS3 attribute starts-with selector：

pageC1.css('table.tableCellDT tr[id^="rowId_"]')

或XPath starts-with()函数：

pageC1.xpath('.//table[@class="tableCellDT"]//tr[starts-with(@id,"rowId_")]')

虽然Nokogiri Node#search方法会根据您编写的内容智能地在CSS或XPath选择器语法之间进行选择，但这并不意味着您可以在同一查询中混合使用CSS和XPath选择器语法。

行动中：

>> require 'nokogiri'
#=> true

>> doc = Nokogiri.HTML <<ENDHTML; true #hide output from IRB
">> <table class="foo"><tr id="rowId_nonono"><td>Nope</td></tr></table>
">> <table class="tableCellDT">
">>   <tr id="rowId_yesyes"><td>Yes1</td></tr>
">>   <tr id="rowId_andme2"><td>Yes2</td></tr>
">>   <tr id="rowIdNONONO"><td>Needs underscore</td></tr>
">> </table>
">> ENDHTML
#=> true

>> doc.css('table.tableCellDT tr[id^="rowId_"]').map(&:text)
#=> ["Yes1", "Yes2"]

>> doc.xpath('.//table[@class="tableCellDT"]//tr[starts-with(@id,"rowId_")]').map(&:text)
#=> ["Yes1", "Yes2"]

Answer 3

谢谢 http://nokogiri.org/Nokogiri/XML/Node.html#method-i-css

以及上面的答案，这里是最终的代码，它解决了我只需要获取所需行的问题，然后只读取每个行中的某些信息：

 pageC1.search('//tr[starts-with(@id, "rowId_")]').each do |row|

# Read the string after _ in rowId_, part of the "id" in <tr>
    rid = row.attribute("id").text.split("_")[1] # => "BullPut"

# Get the URL of the 3rd <a> link in <td> cell 4    
    link = row.css("td[4] a[3]")[0].attributes["href"].text # => "link3?model.itemId=2262&amp;amp;model.source=list"
 end

匹配表行id与公共前缀

3 个答案: