如何仅从 HTML 文档中提取粗体文本？

Question

I need to extract all the bold snippets in the body of an HTML document. I need to do it on server side using Java (not on the browser)

The text on the page can be bold because of tags eg <b> , <h1> , etc., or because of inline CSS styling style="font-weight:bold;", or because of external CSS styling using CSS clases.

I am using Jsoup, but I can use any other library as well to get this done.

Thanks for your time!

Answer 1

A plain JavaScript solution: On sufficiently new browsers, you can use the getPropertyValue method to retrieve the computed style of an element. You can traverse the document tree and check all text nodes; text nodes do not have style, so you need to check their parents:

function consume(string) {
  console.log(string);
}
function traverse(tree) {
  var i;
  if(tree.nodeType === 3) {
    if(getComputedStyle(tree.parentNode).getPropertyValue('font-weight') === 'bold') {
      consume(tree.textContent);
    }
  }
  for(i = 0; i < tree.childNodes.length; i++) {
    traverse(tree.childNodes[i]);
  }
}
traverse(document.body);

Replace consume by your own function that processes the bold texts.

It seems that the computed value of font-weight is bold even when declared as 700 .

Note that this will only pick up text for which font weight is set specifically to bold (700). Elements with a computed font weight of 600, 800, or 900 will most probably appear in bold (depending on availability of typefaces of course). They could be covered by making an obvious modification to the test.

Answer 2

you can use getElementsByTagName()

http://www.w3schools.com/jsref/met_doc_getelementsbytagname.asp

also, can be useful querySelectorAll

https://developer.mozilla.org/en-US/docs/DOM/Document.querySelectorAll

Good luck, Daniel

Answer 3

For the tags and inline style (eg style directly added to html, not contained in an external css stylesheet), you could go with the css selectors link . (for the inline style, it would be [style*="font-weight:bold;"] ).

Answer 4

Simply grab the element by tag name, and loop through:

elem = document.getElementsByTagName("b");

for(i=0;i<elem.length;i++) {
    console.log(elem[i].innerText)
}