puoi fare un ciclo che richiama questa funzione, passandole di volta in volta la nuova stringa dalla quale togli 80 caratteri ad ogni loop. in questo modo, ad ogni ciclo costruisci un'altra stringa formata dagli 80 caratteri del testo iniziale, ai quali aggiungi un
per andare accapo.
la funzione taglia una stringa ad un certo numero di caratteri mantenendo la formattazione XHTML presente; l'ho trovata come open source in qualche sito ma non ricordo quale purtroppo.
Codice PHP:
/*
Taglia una stringa (con codice HTML) ad una specifica lunghezza, mantenendo la formattazione HTML.
Note: this will only work in xhtml strict/transitional due to the checking of "/>" tags and the
requirement of quotations in every value of a tag. It's also only been tested with the
presence of br, img, and a tags, but it should work with the presence of any tag.
*/
function html_substr($posttext, $minimum_length, $length_offset) {
// The approximate length you want the concatenated text to be
$minimum_length = 200;
// The variation in how long the text can be
// in this example text length will be between 200-10=190 characters
// and the character where the last tag ends
$length_offset = 10;
// Reset tag counter & quote checker
$tag_counter = 0;
$quotes_on = FALSE;
// Check if the text is too long
if (strlen($posttext) > $minimum_length) {
// Reset the tag_counter and pass through (part of) the entire text
for ($i = 0; $i < strlen($posttext); $i++) {
// Load the current character and the next one
// if the string has not arrived at the last character
$current_char = substr($posttext,$i,1);
if ($i < strlen($posttext) - 1) {
$next_char = substr($posttext,$i + 1,1);
}
else {
$next_char = "";
}
// First check if quotes are on
if (!$quotes_on) {
// Check if it's a tag
// On a "<" add 3 if it's an opening tag (like <a href...)
// or add only 1 if it's an ending tag (like </a>)
if ($current_char == "<") {
if ($next_char == "/") {
$tag_counter++;
}
else {
$tag_counter = $tag_counter + 3;
}
}
// Slash signifies an ending (like </a> or ... />)
// substract 2
if ($current_char == "/") $tag_counter = $tag_counter - 2;
// On a ">" substract 1
if ($current_char == ">") $tag_counter--;
// If quotes are encountered, start ignoring the tags
// (for directory slashes)
if ($current_char == "\"") $quotes_on = TRUE;
}
else {
// IF quotes are encountered again, turn it back off
if ($current_char == "\"") $quotes_on = FALSE;
}
// Check if the counter has reached the minimum length yet,
// then wait for the tag_counter to become 0, and chop the string there
if ($i > $minimum_length - $length_offset && $tag_counter == 0) {
$posttext = substr($posttext,0,$i + 1) . "...";
return $posttext;
}
}
}
return $posttext;
}