用PHP抓取HTML列表结构

Question

I want to scrape a html list structure, so I can save parent and child separately.

Here's the view source of html

<ul class="categories_list">
    <li><a href="/sports-nutrition">Sports Nutrition</a>
        <ul class="categories_list">
            <li><a href="/protein">Protein</a>
                <ul class="categories_list">
                    <li><a href="/protein-powder">Protein Powder</a>
                        <ul class="categories_list">
                            <li><a href="/whey-protein">Whey Protein</a>
                                <ul class="categories_list">
                                    <li><a href="/whey-protein-isolate">Whey Protein Isolate</a></li>
                                </ul>
                            </li>
                        </ul>
                    </li>
                </ul>
            </li>
        </ul>
        <ul class="categories_list">
            <li><a href="/pre-workout-supplements">Pre Workout Supplements</a></li>
        </ul>
        <ul class="categories_list">
            <li><a href="/creatine">Creatine</a>
                <ul class="categories_list">
                    <li><a href="/creatine-monohydrate">Creatine Monohydrate</a></li>
                </ul>
            </li>
        </ul>
        <ul class="categories_list">
            <li><a href="/amino-acids">Amino Acids</a>
                <ul class="categories_list">
                    <li><a href="/essential-amino-acids">Essential Amino Acids</a>
                        <ul class="categories_list">
                            <li><a href="/bcaa">BCAA</a></li>
                        </ul>
                    </li>
                </ul>
            </li>
        </ul>
        <ul class="categories_list">
            <li><a href="/joint-supplements">Joint Supplements</a>
                <ul class="categories_list">
                    <li><a href="/curcumin">Curcumin</a>
                        <ul class="categories_list">
                            <li><a href="/curcumin-phytosome">Curcumin Phytosome</a></li>
                        </ul>
                    </li>
                </ul>
            </li>
        </ul>
        <ul class="categories_list">
            <li><a href="/energy-endurance">Energy &amp; Endurance</a>
                <ul class="categories_list">
                    <li><a href="/stimulants">Stimulants</a></li>
                </ul>
            </li>
        </ul>
    </li>
</ul>

I am using simple HTML DOM for scraping. I am able to get all categories, but I cannot get them in proper the hierarchy. I also tried the children approach, but that didn't work.

So I am looking for some help in my existing to make it working. Here's my existing code:

$html= file_get_html($url);

foreach ($html->find('ul.categories_list li') as $link) {
    echo $link->plaintext.'<br>';
}

Answer 1

There is this script which tried to get all elements. This needs to be improved upon:

<?php 

require_once("simple_html_dom.php");
$dom = file_get_html("source.php");

getCategory($dom);
print_r($categoryList);

function getCategory(simple_html_dom $dom){
    global $categoryList;

    foreach($dom->find('ul.categories_list li') as $ul){
        //extract the a tag if found
        $categoryName = $ul->find('a',0)->href;
        $categoryLabel = $ul->find('a',0)->innertext;

        $categoryList[] = array(
                                            "categoryName"  =>  $categoryName,
                                            "categoryLabel" =>  $categoryLabel,
                                            );

        //remove a node
        $ul->find('a',0)->outertext = '';

        $string = $ul->innertext;
        if(trim($string) == ''){
            continue;
        }else{
            // die($string);
            $dom2 = str_get_html($string);
            getCategory($dom2);
        }
    }       
}

It basically does recursion filling the $categoryList on each call.