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Can't separate cells properly with simplehtmldom

由 允我心安 提交于 2019-12-12 04:48:26

问题


I am trying to write a web scraper. I want to get all the cells in a row. The row before the one I want has THOROUGHBRED MEETINGS as its plain text value. I can successfully get this row. But I can't figure out how to get the next row's children which are the cells or <td> tags.

if ($foundTag = FindTagByText("THOROUGHBRED MEETINGS", $html))
{
    $cell = $foundTag->parent();
    $row = $cell->parent();
    $nextRow = $row->next_sibling();
    echo "Row: ".$row->plaintext."<br />\n";
    echo "Next Row: ".$nextRow->plaintext."<br />\n";
    $cells = $nextRow->children();

    foreach ($cells as $cell)
    {
        echo "Cell: ".$cell->plaintext."<br />\n";
    }
}

function FindTagByText($text, $html)
{
    // Use Simple_HTML_DOM special selector 'text'
    // to retrieve all text nodes from the document
    $textNodes = $html->find('text');
    $foundTag = null;

    foreach($textNodes as $textNode) 
    {
        if($textNode->plaintext == $text) 
        {
            // Get the parent of the text node
            // (A text node is always a child of
            //  its container)
            $foundTag = $textNode->parent();
            break;
        }
    }

    return $foundTag;
}

Here is the html I am trying to parse:

<tr valign=top>
<td colspan=16 bgcolor=#999999><b>THOROUGHBRED MEETINGS</b></td>

</tr>
<tr valign=top bgcolor="#ffffff">
<td><b>BR</b> <a href="meeting?mtg=br&day=today&curtype=0">SUNSHINE COAST</a></td>
<td>FINE/DEAD</b></td>
<td><font color=#cc0000><b>R1</b></font>@<b>12:30pm</b></td>
<td align=center bgcolor=#cc0000><a href="odds?mting=BR01000"><b><font color=#ffffff>1</a></font></td>
<td align=center><a href="odds?mting=BR02000"><b><font color=black>2</b></font></a></td>
<td align=center><a href="odds?mting=BR03000"><b><font color=black>3</b></font></a></td>

<td align=center><a href="odds?mting=BR04000"><b><font color=black>4</b></font></a></td>
<td align=center><a href="odds?mting=BR05000"><b><font color=black>5</b></font></a></td>
<td align=center><a href="odds?mting=BR06000"><b><font color=black>6</b></font></a></td>
<td align=center><a href="odds?mting=BR07000"><b><font color=black>7</b></font></a></td>
<td align=center><a href="odds?mting=BR08000"><b><font color=black>8</b></font></a></td>
<td bgcolor="#ffffff" colspan=4>&nbsp;</td>
</tr>

Here is my output:

Row: THOROUGHBRED MEETINGS
Next Row: BR SUNSHINE COAST FINE/DEAD R1@12:30pm 1 2 3 4 5 6 7 8   CR NEW ZEALAND FINE/DEAD R3@11:10am 1 2 3 4 5 6 7 8 9   DR HOBART OCAST/HVY R1@12:15pm 1 2 3 4 5 6 7   MR CRANBOURNE OCAST/SLOW R1@12:20pm 1 2 3 4 5 6 7 8   NR COFFS HARBOUR OCAST/SLOW R1@12:45pm 1 2 3 4 5 6 7 8   SR MORUYA FINE/GOOD R1@12:25pm 1 2 3 4 5 6 7 8   VR BENALLA OCAST/SLOW R1@12:35pm 1 2 3 4 5 6 7 8   XR KALGOORLIE FINE/GOOD R1@ 3:00pm 1 2 3 4 5 6 7     HARNESS MEETINGS DT LAUNCESTON SHWRY/GOOD R1@ 4:57pm 1 2 3 4 5 6 7 8 9 10   MT CRANBOURNE OCAST/GOOD R1@ 5:05pm 1 2 3 4 5 6 7 8     GREYHOUND MEETINGS AD GAWLER OCAST/GOOD R1@ 5:10pm 1 2 3 4 5 6 7 8 9 10 11   CD CANBERRA OCAST/GOOD R1@ 5:02pm 1 2 3 4 5 6 7 8 9 10 11   MD SALE FINE/GOOD R1@ 4:54pm 1 2 3 4 5 6 7 8 9 10 11 12
Cell: BR SUNSHINE COAST
Cell: FINE/DEAD
Cell: R1@12:30pm
Cell: 1 2 3 4 5 6 7 8   CR NEW ZEALAND FINE/DEAD R3@11:10am 1 2 3 4 5 6 7 8 9   DR HOBART OCAST/HVY R1@12:15pm 1 2 3 4 5 6 7   MR CRANBOURNE OCAST/SLOW R1@12:20pm 1 2 3 4 5 6 7 8   NR COFFS HARBOUR OCAST/SLOW R1@12:45pm 1 2 3 4 5 6 7 8   SR MORUYA FINE/GOOD R1@12:25pm 1 2 3 4 5 6 7 8   VR BENALLA OCAST/SLOW R1@12:35pm 1 2 3 4 5 6 7 8   XR KALGOORLIE FINE/GOOD R1@ 3:00pm 1 2 3 4 5 6 7     HARNESS MEETINGS DT LAUNCESTON SHWRY/GOOD R1@ 4:57pm 1 2 3 4 5 6 7 8 9 10   MT CRANBOURNE OCAST/GOOD R1@ 5:05pm 1 2 3 4 5 6 7 8     GREYHOUND MEETINGS AD GAWLER OCAST/GOOD R1@ 5:10pm 1 2 3 4 5 6 7 8 9 10 11   CD CANBERRA OCAST/GOOD R1@ 5:02pm 1 2 3 4 5 6 7 8 9 10 11   MD SALE FINE/GOOD R1@ 4:54pm 1 2 3 4 5 6 7 8 9 10 11 12

回答1:


You will not like my answer.

Unfortunately, it seems that mismatched closing tags in the HTML you are parsing are confusing Simple_HTML_DOM. Take a look at this snippet:

<td align=center><a href="odds?mting=BR02000"><b><font color=black>2</b></font></a></td>

If you follow the order of tags of this snippet:

  • <td> is opened
  • <a> is opened
  • <b> is opened
  • <font> is opened

Technically, tags should be closed in the opposite order, but this is how they are closed:

  • </b> is closed
  • </font> is closed
  • </a> is closed
  • </td> is closed

The HTML you are trying to scarp is full of those mistakes, all well as closing tags for tags which are never opened. Simple_HTML_DOM doesn't parse those files properly.

I'm afraid that if you don't have the possibility of modifying the HTML, you'll have to parse the file manually, correcting any errors.

As a note, I've tested your code against the following corrected HTML, and Simple_HTML_DOM parsed it successfully, and your code worked just fine.

<tr valign=top>
<td colspan=16 bgcolor=#999999><b>THOROUGHBRED MEETINGS</b></td>

</tr>
<tr valign=top bgcolor="#ffffff">
<td><b>BR</b> <a href="meeting?mtg=br&day=today&curtype=0">SUNSHINE COAST</a></td>
<td><b>FINE/DEAD</b></td>
<td><font color=#cc0000><b>R1</font></b>@<b>12:30pm</b></td>
<td align=center bgcolor=#cc0000><a href="odds?mting=BR01000"><b><font color=#ffffff>1</a></b></font></td>
<td align=center><a href="odds?mting=BR02000"><b><font color=black>2</font></b></a></td>
<td align=center><a href="odds?mting=BR03000"><b><font color=black>3</font></b></a></td>

<td align=center><a href="odds?mting=BR04000"><b><font color=black>4</font></b></a></td>
<td align=center><a href="odds?mting=BR05000"><b><font color=black>5</font></b></a></td>
<td align=center><a href="odds?mting=BR06000"><b><font color=black>6</font></b></a></td>
<td align=center><a href="odds?mting=BR07000"><b><font color=black>7</font></b></a></td>
<td align=center><a href="odds?mting=BR08000"><b><font color=black>8</font></b></a></td>
<td bgcolor="#ffffff" colspan=4> </td>
</tr>

Edit: As an alternative, you might want to try if DOMDocument::loadHTML has better results. It is available in PHP 5 without external libraries. Check the official documentation.




回答2:


You'll get the first td like this:

$firstTD = $row->first_child();

After that you can get the subsequent ones with:

$firstTD->next_sibling()



回答3:


I got it to work by putting into a DOMDocument() to correct the malformed HTML.

$url = "http://www.acttab.com.au/interbet/venues?day=today";

$doc = new DOMDocument();
$doc->loadHTMLFile($url);

//convert $doc to html
$html = str_get_html($doc->saveHTML());


来源：https://stackoverflow.com/questions/1183482/cant-separate-cells-properly-with-simplehtmldom

标签
php
screen-scraping
simple-html-dom
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