I'm building an application where users highlight and scroll to words in an article they write in search bar. articles come in a Markdown format and I'm using a Markdown-it to render article body.

It works well except for if the word they search for is part of an image URL. it applies regular expression to it and image breaks.

    applyHighlights() {
      let str = this.article.body
      let searchText = this.articleSearchAndLocate
      const regex = new RegExp(searchText, 'gi')
      let text = str
      if (this.articleSearchAndLocate == '') {
        return text
      } else {
        const newText = text.replace(
          regex,
          `<span id="searchResult" >$&</span>`
        )
        return newText
      }
    }

Is there a way to exclude applying regex if it's an Image URL ?

CodePudding user response：

You can use

applyHighlights() {
  let str = this.article.body
  let searchText = this.articleSearchAndLocate
  const regex = new RegExp('(!\\[[^\\][]*]\\([^()]*\\))|'   searchText.replace(/[-\/\\^$* ?.()|[\]{}]/g, '\\$&'), 'gi')
  let text = str
  if (this.articleSearchAndLocate == '') {
    return text
  } else {
    const newText = text.replace(
     regex, function(x, y) { return y ? y :
      '<span id="searchResult" >'   x   '</span>'; })
    return newText
  }
}

Here,

• new RegExp('(!\\[[^\\][]*]\\([^()]*\\))|' searchText.replace(/[-\/\\^$* ?.()|[\]{}]/g, '\\$&'), 'gi') - creates a regex like (!\[[^\][]*]\([^()]*\))|hello that matches and captures into Group 1 a string like ![desc](value), or it matches hellow (if the searchText is hello).
• .replace(regex, function(x, y) { return y ? y : '<span id="searchResult" >' x '</span>'; }) means that if Group 1 (y) was matched, the return value is y itself as is (no replacement is peformed), else, the x (the whole match, searchText) is wrapped with a span tag
• .replace(/[-\/\\^$* ?.()|[\]{}]/g, '\\$&') is necessary to support searchText that can contain special regex metacharacters, see Is there a RegExp.escape function in JavaScript?