I have recently been working on PHP RSS reader script that was supposed to do three different things with RSS description text. To make a teaser RSS text, I was asked to develop the functionality in a such a way that text can be cropped in these three ways.

• with defining the number of words.
• with defining the numbers of characters.
• with defining the number of sentences.

Here is a set of functions that helps you crop a text in three different ways. The usage of the function is also mentioned at the end f the script.
<?php

/**
* cropsentence()
*
* @param mixed $str
* @param mixed $noof
* @param integer $mode
// 0 means crop by no of characters // 1 means crop by no of sentences // 2 means crop by number of words
* @param string $appendwith
* @return
*/
function cropsentence($str, $noof, $mode = 0, $appendwith = “…”)
{
if (strlen($str) > $chars) {
if ($mode == 0) { // 0 means crop by no of characters
$str = substr($str, 0, $noof);
} elseif ($mode == 1) { // 1 means crop by no of sentences
$str = getLeadingSentences($str, $noof);
} elseif ($mode == 2) { // 2 means crop by number of words
$str = wordTrim($str, $noof);

} elseif ($mode < 0 || $mode > 2) { // others means do nothing
echo “The current mode is not correct.”;
}
$str = $str . $appendwith;
return $str;
} else {
return $str;
}
}

//getLeadingSentences
//Copyright (c) 2000 Jason R. Pitoniak.  All rights reserved.
//jason@interbrite.com http://www.interbrite.com

//If you find this code useful, find a bug, or have a suggestion,
//please email me.  Feel free to use this code for any purpose.

/**
* getLeadingSentences()
*
* @param mixed $data
* @param mixed $max
* @return
*/
function getLeadingSentences($data, $max)
{
//given string $data, will return the first $max sentences in that string

//in: $data = the string to parse, $max = maximum # of sentences to return
//returns: string containing the first $max sentences
//(If the # of sentences in the string is less than $max,
//then entire string will be returned.)

//a sentence is any charactors except ., !, and ?
//any number of times,  plus one or more .s, ?s, or !s
//and any leading or trailing whitespace:
$re = “^s*[^.?!]+[.?!]+s*”;
$out = “”;
for ($i = 0; $i < $max; $i++) {
if (ereg($re, $data, $match)) {
//if a sentence is found, take it out of $data and add it to $out
$out .= $match[0];
$data = ereg_replace($re, “”, $data);
} else {
$i = $max;
}
}
return $out;
}

/**
* getLeadingWords()
*
* @param mixed $data
* @param mixed $max
* @return
*/
function getLeadingWords($data, $max)
{
//given string $data, will return the first $max sentences in that string

//in: $data = the string to parse, $max = maximum # of sentences to return
//returns: string containing the first $max sentences
//(If the # of sentences in the string is less than $max,
//then entire string will be returned.)

//a sentence is any charactors except ., !, and ?
//any number of times,  plus one or more .s, ?s, or !s
//and any leading or trailing whitespace:
$re = “^s*[^.?!]+[.?!]+s*”;
$out = “”;
for ($i = 0; $i < $max; $i++) {
if (ereg($re, $data, $match)) {
//if a sentence is found, take it out of $data and add it to $out
$out .= $match[0];
$data = ereg_replace($re, “”, $data);
} else {
$i = $max;
}
}
return $out;
}

/**
* wordTrim()
*
* @param mixed $str
* @param mixed $len
* @return
*/
function wordTrim($str, $len)
{
$wordCount = 0;
$charCount = 0;

$length = strlen(strip_tags($str));
for ($i = 0; $i < $length; $i++) {
if ($str[$i] == ‘ ’) {
$wordCount++;
$charCount++;
if ($wordCount == $len)
break;
} else {
$charCount++;
} # end if
} # end for loop

$newstr = substr($str, 0, $charCount);
return $newstr;
} # end function

# Example used for testing purpose

$str2 = “Hello there I work for you. I have been working for other guys, but you are the coolest guy among them.
Also I really like the way you guide me with new technologies and the latest trends. You always tell me to keep working hard!”;
echo cropsentence($str2, 22, 2);

?>

Usage

cropsentence($str, $noof, $mode, $appendwith );

$str: This is the string / text to be cropped

$noof: Number of characters/words/sentences based on the $mode parameter

$mode: Three values of $mode can be defined

1. 0 means crop by no of characters.
2. 1 means crop by no of sentences .
3. 2 means crop by number of words.

$appendwith: This can be any characters like ‘…’ , ‘…more’ etc which will be appended with the cropped text when its returned.

Download:

You can download the script here.