使用jquery获取两个字符串之间的字符串

Question

如果我有这个 HTML

<div class="comment-body">
[img]http://topnews.net.nz/images/YouTube-3.jpg[/img] random text here
</div>

<div class="comment-body">
[img]http://blog.brightcove.com/sites/all/uploads/FACEBOOK%20ICON.png[/img] random text here
</div>

如何使用 jquery 提取 [img] 和 [/img] 之间的值并将其设置为 <img> 元素中的变量 data-src2="" 给予

<div class="comment-body">
<img src="samesrc" class="commentimg" data-src2="http://topnews.net.nz/images/YouTube-3.jpg"/> random text here
</div>

<div class="comment-body">
<img src="samesrc" class="commentimg" data-src2="http://blog.brightcove.com/sites/all/uploads/FACEBOOK%20ICON.png"/> random text here
</div>

对于我所尝试的东西，我没有什么可提供的，因为我不知道如何提取 [img] 和 [/img] 之间的值

但总的来说 THIS 是我想要实现的目标，如果它没有意义的话！

Answer 1

经过测试，现在可以使用（原始版本没有遍历所有 .comment-body 元素，或者正确找到 substring()）：

var divString, imgString;
$('.comment-body').each(
    function(){
        divString = $(this).text();
        imgString = divString.substring(divString.indexOf('[img]') + 5,divString.indexOf('[/img]'));
        console.log(imgString);
    });

JS Fiddle.

---

编辑，因为我有点无聊，所以把上面的变成了一个更通用的函数：

function findStringBetween(elem,bbTagStart,bbTagClose){
    var tag = bbTagStart;

    function impliedEndTag(tag){
        var impliedEnd = tag.replace(tag.substring(0,1),tag.substring(0,1) + '/');
        return impliedEnd;
    }

    var endTag = bbTagClose || impliedEndTag(tag);

    var divString = $(elem).text();
    var tagString = divString.substring(divString.indexOf('[img]') + tag.length,divString.indexOf('[/img'));
    return tagString;
}
$('.comment-body').each(
    function(){
        /* call with two, or three arguments (the third is the optional 'bbTagClose':
            1. elem = this, the DOM node,
            2. '[img]' = whatever bbCode thing you want to use (I'm not sure what's available),
            3. 'bbTagClose' = the end tag of the bbCode, assuming that the end-tag is the same as
                the opening tag, except with a '/' as the second character, the impliedEndTag() function
                will take care of it for you.
        */
        var elemString = findStringBetween(this,'[img]');
        $(this).replaceWith('<img src="' + elemString + '" class="commentimg" data-src2="'+ elemString +'"/>');
    });

JS Fiddle demo.

---

编辑以下来自 OP 的进一步问题（在 cmets 中，如下）：

...该函数向每个带有注释主体类的 div 添加一个 '' 我如何才能只将代码应用于包含 [img]image src here[/img]

的注释主体元素

我添加了一些健全性检查，以确保在未找到定义的标签时函数返回 false：

function findStringBetween(elem,bbTagStart,bbTagClose){
    var tag = bbTagStart;

    function impliedEndTag(tag){
        var impliedEnd = tag.replace(tag.substring(0,1),tag.substring(0,1) + '/');
        return impliedEnd;
    }

    var endTag = bbTagClose || impliedEndTag(tag);
    var divString = $(elem).text().trim(); // added .trim() to remove white-spaces

    if (divString.indexOf(tag) != -1){ // makes sure that the tag is within the string
        var tagString = divString.substring(divString.indexOf('[img]') + tag.length,divString.indexOf('[/img'));
        return tagString;
    }
    else { // if the tag variable is not within the string the function returns false
        return false;
    }
}
$('.comment-body').each(
    function(){
        /* call with two, or three arguments (the third is the optional 'bbTagClose':
            1. elem = this, the DOM node,
            2. '[img]' = whatever bbCode thing you want to use (I'm not sure what's available),
            3. 'bbTagClose' = the end tag of the bbCode, assuming that the end-tag is the same as
                the opening tag, except with a '/' as the second character, the impliedEndTag() function
                will take care of it for you.
        */
       var imgLink = findStringBetween(this,'[img]');
        if (imgLink){ // only if a value is set to the variable imgLink will the following occur
            $(this).replaceWith('<img src="' + imgLink + '" class="commentimg" data-src2="'+ imgLink+'"/>');
        }
    });

JS Fiddle demo.

---

编辑以回应 OP 的进一步问题（在 cmets 中，如下）：

[是否]有办法阻止它删除此示例“此处的随机文本”中的文本[？]

是的，你可以将.append()，或者.prepend()的图片放入元素中，先更新div的文字后，在下面的代码中我已经去掉了[img]...[/img]这个字符串，留下just 其他文本，将该文本插入到 .comment-body 元素中，然后将 img 附加到该元素中，而不是使用 replaceWith()：

function findStringBetween(elem,bbTagStart,bbTagClose){
    var tag = bbTagStart;

    function impliedEndTag(tag){
        var impliedEnd = tag.replace(tag.substring(0,1),tag.substring(0,1) + '/');
        return impliedEnd;
    }

    var endTag = bbTagClose || impliedEndTag(tag);
    var divString = $(elem).text().trim();

    if (divString.indexOf(tag) != -1){
        var elemInfo = [];
        elemInfo.imgString = divString.substring(divString.indexOf(tag) + tag.length,divString.indexOf(endTag));
        elemInfo.text = divString.replace(tag + elemInfo.imgString + endTag, '');
        return elemInfo;
    }
    else {
        return false;
    }
}
$('.comment-body').each(
    function(){
        /* call with two, or three arguments (the third is the optional 'bbTagClose':
            1. elem = this, the DOM node,
            2. '[img]' = whatever bbCode thing you want to use (I'm not sure what's available),
            3. 'bbTagClose' = the end tag of the bbCode, assuming that the end-tag is the same as
                the opening tag, except with a '/' as the second character, the impliedEndTag() function
                will take care of it for you.
        */
       var elemInfo = findStringBetween(this,'[img]');
        if (elemInfo.imgString){
            // or .prepend() if you prefer
            $(this).text(elemInfo.text).append('<img src="' + elemInfo.imgString + '" class="commentimg" data-src2="'+ elemInfo.imgString +'"/>');
        }
    });

JS Fiddle demo.

---

参考资料：

• jQuery 的东西：
  • append()。
  • each()。
  • prepend()。
  • replaceWith()。
  • text()。
• JavaScript（全部在Mozilla Developer Network的JavaScript documentation resource：
  • indexOf()。
  • length。
  • replace()。
  • substring()。
  • trim()。

Answer 2

大卫·托马斯所写的另一种答案。

实现此代码的另一种方法是使用正则表达式。

// inputText - input text that contains tags
// tagName - name of the tag we want to replace
// tagReplace - replacement for the tag, "$1" will get replaced by content of the tag
function replaceText(inputText, tagName, tagReplace) {
  var regExp = new RegExp('\\[' + tagName+ '\\]([^\\[]*)\\[\/' + tagName + '\\]', 'g');
  return inputText.replace(regExp, tagReplace);
}

$('.comment-body').each(function() {
  var $this = $(this);
  var replacedText = replaceText($this.text(), 'img', '<img src="$1" \/>');
  $this.html(replacedText);
});

此实现还将替换评论中的多个标签。

见THIS代码sn-p。

注 1：

在实际环境中实现此代码时，请考虑为 replaceText() 之外的所有已处理标记名称预先创建正则表达式，这样就不会在每次调用 replaceText() 时创建 regExp。

注2：

要获得问题更改中的确切输出：

  var replacedText = replaceText($this.text(), 'img', '<img src="$1" \/>');

到

  var replacedText = replaceText($this.text(), 'img', '<img src="samesrc" class="commentimg" data-src2="$1" \/>');

Answer 3

此函数在任何字符串中查找任何给定的 bbcode，如果需要，您可以将其配置为从这些 bbcode 中替换或提取内容作为数组。

//search str 
var search_str = "I love this [img]question.png[/img] Flowers, and [img]answer_1-1.png[/img] you say is that [img]answer_2-1.png[/img] good Point."
//using example
var str = bbcode_search_and_replace($('#search_str').text(),"[img]","[/img]");
$('#search_str').html(str);

function bbcode_search_and_replace(search_str, bb_opening_tag, bb_closing_tag) {
            //search str length
           var sLength = String(search_str).length;
           //bbcode opening tag length
           var fPart_length = String(bb_opening_tag).length;
           //bbcode closing tag length
           var ePart_length = String(bb_closing_tag).length;
           //position index for opening tag 
           var start_idx = 0;
           //position index for closing tag 
           var end_idx = 0; 
           //searching index for opening tag
           var pos_sIdx = 0;
           //position index for closing tag
           var pos_eIdx = 0;
           //var replacement = '[image]';
           var arr = [];
           var idx = 0;           

           //loop
           while(start_idx !== -1) {
               arr[idx] = {};                  

               start_idx = String(search_str).indexOf(bb_opening_tag,pos_sIdx);
               //check for ending
               if(start_idx === -1) {
                   //if exist, last str after closing tag
                   if(idx > 0) arr[idx]['str'] = search_str.substring(pos_sIdx);
                   console.log("arr[idx]['str'] = " + arr[idx]['str']);
                   break;
               }
               //end position index
               pos_eIdx = start_idx + fPart_length;
               end_idx = String(search_str).indexOf(bb_closing_tag,pos_eIdx);                   
               //save str inside bbtags
               arr[idx]['str'] = search_str.substring(pos_sIdx, start_idx);
               console.log("arr[idx]['str'] = " + arr[idx]['str']);
               arr[idx]['src'] =  "<img src = 'img/" + search_str.substring(start_idx + fPart_length, end_idx) + "' />";
               console.log("arr[idx]['src'] = " + arr[idx]['src']);
               arr[idx]['pos_start'] = start_idx + fPart_length;
               arr[idx]['pos_end'] = end_idx;                                

               //Update array and start pos indexes
               idx++;
               pos_sIdx = end_idx + ePart_length;                
          }

           var k = 0;
           var str = "";
           while(k < arr.length) {
               if(arr[k]['src'] === undefined) arr[k]['src'] = "";
               str += arr[k]['str'] + arr[k]['src'];
               k++;
           }

           return str;
        }  

Answer 4

使用JavaScript match()函数，非常好用

如果你有一个字符串“快速棕色狐狸跳过懒狗。”

& 你需要介于“quick”和“lazy”之间的文本

在下面使用

<script type="text/javascript">
   var myStr = "The quick brown fox jumps over the lazy dog.";
   var subStr = myStr.match("quick(.*)lazy");
   alert(subStr[1]);
</script>

希望对你有帮助！！