Detect Once a Certain Word Has Just Been Entered in a Textarea

问题

Considering features like EditArea's and CodeMirror's autocomplete, I was wondering if, like Dreamweaver, there is a way to detect if the last word you entered is in a certain list then provide the same kind of suggestion box but with the function's arguments. I imagine you would use a regular expression on the entire field or possibly split() the whole thing (or the current line) then use the length attribute of the array to find the last bit of text, then do something involving an indexOf-like operation; however, this seems like it would get a bit resource-intensive. It almost looks like I've answered my own question, but it always helps to fully explain one's quandary, especially publicly. There's gotta be a better solution than mine. I appreciate any input. Thank you.

回答1:

Put the list of words to match in an object, have the text or options to display as the value. Then on keyup or keypress you can get the last word of the text area using a function like:

function showLastWord(id){
  var el = document.getElementById(id);
  var lastWord = el.value.match(/\w+$/);
  return lastWord? lastWord[0] : '';
}

Then check if the word is in the list and do stuff appropriately.

Edit

A small example is:

<textarea onkeyup="showHelp(this);"></textarea>
<script>

var getLastWord = (function() {
    re = /\w+$/;
    return function (s){
      var lastWord = s.match(re);
      return lastWord? lastWord[0] : '';
    }
}());

var keyWords = {foo:'foo was typed',bar:'bar was typed'};

function showHelp(el) {
  var lastWord = getLastWord(el.value);

  // Check for matching own property of keyWords
  if (keyWords.hasOwnProperty(lastWord)) {

    // Do stuff
    console.log(keyWords[lastWord]);
  }
}

来源：https://stackoverflow.com/questions/8206613/detect-once-a-certain-word-has-just-been-entered-in-a-textarea

标签

javascript

regex

autocomplete

textarea