如何修复丢失的HTML <open> ＆ <close> HTML字符串中间的标签

Question

I have to validate HTML string in my project,

I have an html with :

<ul>
    <li>Test 1</li>
    <ol>
        <li>Test 2</li>        
    </ol>
    <li>Test 1</li>
</ul>

Required Output is :

<ul>
    <li>Test 1</li>
</ul>
<ol>
    <li>Test 2</li>
</ol>
<ul>
    <li>Test 1</li>
</ul>

In HTML code </ul> and <ul> tags are missing. Now in this case how to Search where are the missing tag and how to insert appropriate ending tag and beginning tags in proper places.

I tried HTML agility pack and Tidy library, but I couldn't find better solution for this issue.

Answer 1

Using any DOM manipulation library, you will need to create a ruleset describing which elements can be children of a <ul> element. Iterate over all of its children, and when you find a child ( <ol> ) that's not allowed, move all subsequent children, including the <ol> child, to the parent of the <ul> element, placing it at the index of the <ul> element + 1.