Nodejs String Truncate truncate(max_len, appender)

Method Source Code

'use strict';//  w  ww.j  a v  a  2 s .  c  o m

/**
 * Truncate string nicely by appending '...'
 * @method
 * @param  {Integer=} max_len
 * @param  {String=}  appender
 * @return {String}
 */
String.prototype.truncate = function(max_len, appender) {
  max_len  = max_len || 80;
  appender = appender || '...';
  if (appender.length >= max_len) {
    throw Error('appender length is greater or equal to max_len');
  }
  if (this.length <= max_len) {
    return this;
  } else {
    return this.substr(0, max_len - appender.length) + appender;
  }
};

/**
 * Cast buffer to hex string and truncate it nicely by appending '...'
 * @method
 * @param  {Integer=} max_len
 * @param  {string=}  appender
 * @return {String}
 */
Buffer.prototype.truncate = function(max_len, appender) {
  return this.toString('hex').truncate(max_len, appender);
};

Related

1. truncate(length)

   String.prototype.truncate = function(length) {
     length = typeof length !== 'undefined' ? length : 100;
     if (this.length > length) {
       var str = this.substring(0, length);
       str = str.substring(0, Math.min(str.length, str.lastIndexOf(" ")));
       str = str + " ...";
       return str;
     } else {
       return this;
   ...
   

2. truncate(length, substitute)

   String.prototype.truncate = String.prototype.truncate || function (length, substitute) {
     return this.length > (length || 30) ? this.substr(0, (length || 30)).replace(/\s$/, '') + (substitute || '?') : this.toString()
   

3. truncate(length, truncation)

   String.prototype.truncate = function(length, truncation) {
     length = length || 30;
     truncation = truncation === undefined ? '...' : truncation;
     return this.length > length ?
       this.slice(0, length - truncation.length) + truncation : String(this);
   };
   

4. truncate(length, truncation)

   String.prototype.truncate = function(length, truncation) {
       length = length || 30;
       truncation = (typeof truncation == 'undefined') ? '…' : truncation;
       return this.length > length
           ? this.slice(0, length) + truncation
           : this;
   };
   

5. truncate(length, useWordBoundary)

   String.prototype.truncate = function(length, useWordBoundary) {
       var toLong = this.length > length,
       s_ = toLong ? this.substr(0, length - 1) : this;
       s_ = useWordBoundary && toLong ? s_.substr(0, s_.lastIndexOf(' ')) : s_;
       return toLong ? s_ + '…' : s_;
   };
   

6. truncate(maxlength)

   String.prototype.truncate = function (maxlength) {
       if (!this) {
           return '';
       if (!maxlength) {
           maxlength = 20;
       return (this.length > maxlength) ? this.slice(0, maxlength - 3) + '...' : this;
   };
   ...
   

7. truncate(n)

   String.prototype.truncate = function(n){
         return this.substr(0,n-1)+(this.length>n?'...':'');
   };
   

8. truncate(n)

   String.prototype.truncate = function(n) {
     var tooLong = this.length > n,
         string = tooLong ? this.substr(0,n-1) : this;
     string = tooLong ? string.substr(0,string.lastIndexOf(' ')) : string;
     return  tooLong ? string + '...' : string;
   };
   

9. truncate(options)

   String.prototype.truncate = function (options) {
     var length = (options && options.length) || 50;
     var ending = (options && options.ending) || "...";
     var truncated = this.slice(0, length);
     if (truncated.length < this.length)
       truncated += ending;
     return truncated;
   };