将 HTML 页面解析为 DOM 树的 JSON 表示

Question

我有一个 index.html 文件，并且该文件中有 div 标签，我试图从 html 页面中的所有 div 标签中获取内容，但我只从第一个 div 标签中获取内容，我需要html页面中所有div的内容。

这是我的代码：

<?php

    // Function to get the contents of an attribute of an HTML tag
    function get_attribute_contents($element) {
        $obj_attribute = array ();
        foreach ( $element->attributes as $attribute ) {
            $obj_attribute [$attribute->name] = $attribute->value;
        }
        return $obj_attribute;
    }

    // Function to get contents of a child element of an HTML tag
    function get_child_contents($element) {
        $obj_child = array ();
        foreach ( $element->childNodes as $subElement ) {
            if ($subElement->nodeType != XML_ELEMENT_NODE) {
                if (trim ( $subElement->wholeText ) != "") {
                    $obj_child ["value"] = $subElement->wholeText;
                }
            } else {
                if ($subElement->getAttribute ( 'id' )) {
                    $obj_child [$subElement->tagName . "#" . $subElement->getAttribute ( 'id' )] = get_tag_contents ( $subElement );
                } else {
                    $obj_child [$subElement->tagName] = get_tag_contents ( $subElement );
                }
            }
        }
        return $obj_child;
    }

    // Function to get the contents of an HTML tag
    function get_tag_contents($element) {
        $obj_tag = array ();
        if (get_attribute_contents ( $element )) {
            $obj_tag ["attributes"] = get_attribute_contents ( $element );
        }
        if (get_child_contents ( $element )) {
            $obj_tag ["child_nodes"] = get_child_contents ( $element );
        }

        return $obj_tag;
    }

    // Function to convert a DOM element to an object
    function element_to_obj($element) {
        $object = array ();
        $tag = $element->tagName;
        $object [$tag] = get_tag_contents ( $element );
        return $object;
    }

    // Function to convert an HTML to a DOM element
    function html_to_obj($html) {
        $dom = new DOMDocument ();
        $dom->loadHTML ( $html );
        $docElement = $dom->documentElement;
        return element_to_obj ( $dom->documentElement );
    }

    // Reading the contents of an HTML file
    $html = file_get_contents ( 'index.html' );
    header ( "Content-Type: text/plain" );

    // Coverting the HTML to JSON
    $output = json_encode ( html_to_obj ( $html ) );

    // Writing the JSON output to an external file
    $file = fopen ( "js_output.json", "w" );
    fwrite ( $file, $output );
    fclose ( $file );

    echo "HTML to JSON conversion has been completed.\n";
    echo "Please refer to json_output.json to view the JSON output.";
?>

html文件是：

<div class="issue-message">
    Rename this package name to match the regular expression
    '^[a-z]+(\.[a-z][a-z0-9]*)*$'.
    <button class="button-link issue-rule icon-ellipsis-h little-spacer-left" aria-label="Rule Details"></button>
</div>
<div class="issue-message">
    Replace this use of System.out or System.err by a logger.
    <button class="button-link issue-rule icon-ellipsis-h little-spacer-left" aria-label="Rule  Details"></button>
</div>
<div class="issue-message">
    Replace this use of System.out or System.err by a logger.
    <button class="button-link issue-rule icon-ellipsis-h little-spacer-left" aria-label="Rule  Details"></button>
</div>
<div class="issue- 
    message">
    Rename this package name to match the regular expression '^[a-z]+
    (\.[a-z][a-z0-9]*)*$'.
    <button
        class="button-link issue-rule icon-ellipsis-h little-spacer-left" aria-label="Rule Details"></button>
</div>
<div class="issue-message">
    Replace this use of System.out or System.err by a logger.
    <button class="button-link issue-rule icon-ellipsis-h little-spacer-left" aria-label="Rule  Details"></button>
</div>

作为以下文件中代码的输出，我将仅存在于第一个 div 标记中的内容的 json 转换为：

{
  "html": {
    "child_nodes": {
      "body": {
        "child_nodes": {
          "p": {
            "child_nodes": {
              "value": "Issues found:"
            }
          },
          "div": {
            "attributes": {
              "class": "issue-message"
            },
            "child_nodes": {
              "value": "This block of commented-out lines of code should be removed.",
              "button": {
                "attributes": {
                  "class": "button-link issue-rule icon-ellipsis-h little-spacer-left",
                  "aria-label": "Rule Details"
                }
              }
            }
          }
        }
      }
    }
  }
}

Answer 1

您只看到一个 DIV 元素的原因是 您正在创建一个关联数组，它的元素（在您的情况下为 DIV）在迭代时被覆盖 DIV 元素，因为 它们位于同一树级别。

您的代码一团糟，我认为这对于这么简单的事情来说太过分了。 这是我的代码版本 - 将 HTML DOM 元素解析为关联的 PHP 数组：

注意：为了克服对相同元素的覆盖，我只是将子元素推入索引数组并将标记名存储为元素。

一种简单的递归方法（打包到静态类中）：

You can see a working example here

<?php
class DomToArray {

    /* Method to get the contents of the attributes
     * @param $element -> Object DomElement
     * @return Array
     */
    private static function get_attribute_contents($element) {
        $obj_attribute = [];
        if ($element->hasAttributes()) {
            foreach ( $element->attributes as $attribute ) {
                $obj_attribute [$attribute->name] = $attribute->value;
            }
        }
        return $obj_attribute;
    }

    /* Recursive method to walk the DOM tree and Extract the metadata we need
     * @param $element-> Object DomElement
     * @param &$tree-> Array Element
     * @param $text -> String || null
     * @return Array
     */
    private static function get_tag_contents($element, &$tree, $text = null) {
        //The node representation in our json model
        $tree = array(
            "tagName"     => ($element->nodeType === 1 ? $element->tagName : $element->nodeName),
            "nodeType"    => $element->nodeType,
            "attributes"  => self::get_attribute_contents($element),
            "value"       => $text,
            "child_nodes" => []
        );

        // iterate over children and Recursively parse them:
        if ($element->hasChildNodes()) {
            foreach ($element->childNodes as $subElement) {
                $text = null;
                if ($subElement->nodeType === 3) {
                    $text = trim(preg_replace('/\s+/', ' ', $subElement->textContent)); //Removes also \r \n
                    if (empty($text)) continue; //Jump over empty text elements.
                }
                self::get_tag_contents($subElement, $tree["child_nodes"][], $text);
            }
        }
    }
    /* Main Method to convert an HTML string to an Array of nested elements that represents the DOM tree.
     * @param &$html -> String
     * @return Array
     */
    public static function html_to_obj(&$html) {
        $dom = new DOMDocument ();
        $dom->loadHTML($html);
        $tree = [];
        self::get_tag_contents($dom->documentElement, $tree);
        return $tree;
    }
}

现在考虑这个程序并输入：

$source = "
<div class=\"issue-message\">
    Rename this package name to match the regular expression
    '^[a-z]+(\.[a-z][a-z0-9]*)*$'.
    <button class=\"button-link issue-rule icon-ellipsis-h little-spacer-left\" aria-label=\"Rule Details\"></button>
</div>
<div class=\"issue-message\">
    Replace this use of System.out or System.err by a logger.
    <button class=\"button-link issue-rule icon-ellipsis-h little-spacer-left\" aria-label=\"Rule  Details\"></button>
</div>
";

$array_tree = DomToArray::html_to_obj($source);
echo json_encode($array_tree);

输出将是：

{
  "tagName": "html",
  "nodeType": 1,
  "attributes": [],
  "value": null,
  "child_nodes": [
    {
      "tagName": "body",
      "nodeType": 1,
      "attributes": [],
      "value": null,
      "child_nodes": [
        {
          "tagName": "div",
          "nodeType": 1,
          "attributes": {
            "class": "issue-message"
          },
          "value": null,
          "child_nodes": [
            {
              "tagName": "#text",
              "nodeType": 3,
              "attributes": [],
              "value": "Rename this package name to match the regular expression '^[a-z]+(\\.[a-z][a-z0-9]*)*$'.",
              "child_nodes": []
            },
            {
              "tagName": "button",
              "nodeType": 1,
              "attributes": {
                "class": "button-link issue-rule icon-ellipsis-h little-spacer-left",
                "aria-label": "Rule Details"
              },
              "value": null,
              "child_nodes": []
            }
          ]
        },
        {
          "tagName": "div",
          "nodeType": 1,
          "attributes": {
            "class": "issue-message"
          },
          "value": null,
          "child_nodes": [
            {
              "tagName": "#text",
              "nodeType": 3,
              "attributes": [],
              "value": "Replace this use of System.out or System.err by a logger.",
              "child_nodes": []
            },
            {
              "tagName": "button",
              "nodeType": 1,
              "attributes": {
                "class": "button-link issue-rule icon-ellipsis-h little-spacer-left",
                "aria-label": "Rule  Details"
              },
              "value": null,
              "child_nodes": []
            }
          ]
        }
      ]
    }
  ]
}

希望我能帮到你。