Javascript 使用querySelectorAll从html页面提取latex方程块

我尝试从HTML页面（使用

latex2html

生成）中提取latex方程公式，以便用

mathjax

公式替换latex方程图像

首先，我有以下想法，这里有一个例子：

<div align="CENTER" class="mathdisplay"><a name="eq407"></a><!-- MATH
 \begin{equation}
\text{d}\,(\mathbf{V}\,\cdot\,\mathbf{n})=\mathbf{V_{M}}(M')\,\cdot\,\mathbf{n}-\mathbf{V}(M)\,\cdot\,\mathbf{n}=[\mathbf{V_{M}}(M')-\mathbf{V}(M)]\,\cdot\,\mathbf{n}=\text{d}\,\mathbf{V}\,\cdot\,\mathbf{n}
\end{equation}
 -->
<table class="equation" cellpadding="0" width="100%" align="CENTER">
<tr valign="MIDDLE">
<td nowrap align="CENTER"><span class="MATH">d<img width="538" height="38" align="MIDDLE" border="0" src="img1929.gif" alt="$\displaystyle \,(\mathbf{V}\,\cdot\,\mathbf{n})=\mathbf{V_{M}}(M')\,\cdot\,\mat...
...V}(M)\,\cdot\,\mathbf{n}=[\mathbf{V_{M}}(M')-\mathbf{V}(M)]\,\cdot\,\mathbf{n}=$">d<img width="56" height="34" align="MIDDLE" border="0" src="img1930.gif" alt="$\displaystyle \,\mathbf{V}\,\cdot\,\mathbf{n}$"></span></td>
<td nowrap class="eqno" width="10" align="RIGHT">
(<span class="arabic">5</span>.<span class="arabic">70</span>)</td></tr>
</table></div>

输入：

  <div align="CENTER" class="mathdisplay"><a name="eq402"></a><!-- MATH
 \begin{equation}
\text{d}\,v_{k}=\partial_{j}\,v_{k}\,\dfrac{\text{d}\,y^{j}}{\text{d}\,s}\,\text{d}\,s
\end{equation}
 -->
<table class="equation" cellpadding="0" width="100%" align="CENTER">
<tr valign="MIDDLE">
<td nowrap align="CENTER"><span class="MATH">d<img width="150" height="65" align="MIDDLE" border="0" src="img1919.gif" alt="$\displaystyle \,v_{k}=\partial_{j}\,v_{k}\,\dfrac{\text{d}\,y^{j}}{\text{d}\,s}\,\text{d}\,s$"></span></td>
<td nowrap class="eqno" width="10" align="RIGHT">
(<span class="arabic">5</span>.<span class="arabic">65</span>)</td></tr>
</table></div>

这可能足够了，但我注意到，有时在HTML页面中，我为“

alt

”属性设置了一个不完整的公式，下面是一个示例：

<div align="CENTER" class="mathdisplay"><a name="eq407"></a><!-- MATH
 \begin{equation}
\text{d}\,(\mathbf{V}\,\cdot\,\mathbf{n})=\mathbf{V_{M}}(M')\,\cdot\,\mathbf{n}-\mathbf{V}(M)\,\cdot\,\mathbf{n}=[\mathbf{V_{M}}(M')-\mathbf{V}(M)]\,\cdot\,\mathbf{n}=\text{d}\,\mathbf{V}\,\cdot\,\mathbf{n}
\end{equation}
 -->
<table class="equation" cellpadding="0" width="100%" align="CENTER">
<tr valign="MIDDLE">
<td nowrap align="CENTER"><span class="MATH">d<img width="538" height="38" align="MIDDLE" border="0" src="img1929.gif" alt="$\displaystyle \,(\mathbf{V}\,\cdot\,\mathbf{n})=\mathbf{V_{M}}(M')\,\cdot\,\mat...
...V}(M)\,\cdot\,\mathbf{n}=[\mathbf{V_{M}}(M')-\mathbf{V}(M)]\,\cdot\,\mathbf{n}=$">d<img width="56" height="34" align="MIDDLE" border="0" src="img1930.gif" alt="$\displaystyle \,\mathbf{V}\,\cdot\,\mathbf{n}$"></span></td>
<td nowrap class="eqno" width="10" align="RIGHT">
(<span class="arabic">5</span>.<span class="arabic">70</span>)</td></tr>
</table></div>

任何帮助都很好

您可以使用本机支持实用节点过滤策略的，如

NodeFilter.SHOW\u COMMENT

var walker=document.createTreeWalker(
document.documentElement，
NodeFilter.SHOW\u注释
),
frag=document.createDocumentFragment（），
li，节点；
while（node=walker.nextNode（））{
li=document.createElement（'li'）；
li.textContent=node.textContent；
frag.appendChild（李）；
}
document.getElementById（'comment-list'）.appendChild（frag）



<div align="CENTER" class="mathdisplay"><a name="eq407"></a><!-- MATH
 \begin{equation}
\text{d}\,(\mathbf{V}\,\cdot\,\mathbf{n})=\mathbf{V_{M}}(M')\,\cdot\,\mathbf{n}-\mathbf{V}(M)\,\cdot\,\mathbf{n}=[\mathbf{V_{M}}(M')-\mathbf{V}(M)]\,\cdot\,\mathbf{n}=\text{d}\,\mathbf{V}\,\cdot\,\mathbf{n}
\end{equation}
 -->
<table class="equation" cellpadding="0" width="100%" align="CENTER">
<tr valign="MIDDLE">
<td nowrap align="CENTER"><span class="MATH">d<img width="538" height="38" align="MIDDLE" border="0" src="img1929.gif" alt="$\displaystyle \,(\mathbf{V}\,\cdot\,\mathbf{n})=\mathbf{V_{M}}(M')\,\cdot\,\mat...
...V}(M)\,\cdot\,\mathbf{n}=[\mathbf{V_{M}}(M')-\mathbf{V}(M)]\,\cdot\,\mathbf{n}=$">d<img width="56" height="34" align="MIDDLE" border="0" src="img1930.gif" alt="$\displaystyle \,\mathbf{V}\,\cdot\,\mathbf{n}$"></span></td>
<td nowrap class="eqno" width="10" align="RIGHT">
(<span class="arabic">5</span>.<span class="arabic">70</span>)</td></tr>
</table></div>

 var text = document.createTextNode(puretext);
                    img.parentNode.insertBefore(text, img);
                    img.style.display = 'none';