Generate pure text using php

Question

I'm using a service that I end up with a generated string. Strings are usually like:

Hello   Mr   John Doe, you are now registered \t.
Hello &nbsb; Mr   John Doe, your phone number is &nbsb; 555-555-555 &nbs; \n

I need to remove all html entities and all \t and \n and etc.

I can use html_entity_decode, to remove none breaking spaces, and use str_replace for removing \t or \n, but is there a more general way? some thing that makes you sure nothing but alphabet characters exist in the string (some string that doesn't contain codes).

Answer 1

If I understood your case correctly, you basically want to convert from HTML to plain text.

Depending on the complexity of your input and the robustness and accuracy needed, you have a couple of options:

• Use strip_tags() to remove HTML tags, mb_convert_encoding() with HTML-ENTITIES as source encoding to decode entities and either strtr() or preg_replace() to make any additional replacement:

  $html = "<p>Hello &nbsp; Mr &nbsp; John Doe, you are now registered.
      Hello &nbsp; Mr &nbsp; John Doe, your phone number is &nbsp; 555-555-555 &nbsp;
      Test: &euro;/&eacute;</p>";
  
  $plain_text = $html;
  $plain_text = strip_tags($plain_text);
  $plain_text = mb_convert_encoding($plain_text, 'UTF-8', 'HTML-ENTITIES');
  $plain_text = strtr($plain_text, [
      "\t" => ' ',
      "\r" => ' ',
      "\n" => ' ',
  ]);
  $plain_text = preg_replace('/\s+/u', ' ', $plain_text);
  
  var_dump($html, $plain_text);
  

• Use a proper DOM parser, plus maybe preg_replace() for further tweaking:

  $html = "<p>Hello &nbsp; Mr &nbsp; John Doe, you are now registered.
      Hello &nbsp; Mr &nbsp; John Doe, your phone number is &nbsp; 555-555-555 &nbsp;
      Test: &euro;/&eacute;</p>";
  
  $dom = new DOMDocument();
  libxml_use_internal_errors(true);
  $dom->loadHTML($html);
  libxml_use_internal_errors(false);
  $xpath = new DOMXPath($dom);
  
  $plain_text = '';
  foreach ($xpath->query('//text()') as $textNode) {
      $plain_text .= $textNode->nodeValue;
  }
  $plain_text = preg_replace('/\s+/u', ' ', $plain_text);
  
  var_dump($html, $plain_text);
  

Both solutions should print something like this:

string(169) "<p>Hello &nbsp; Mr &nbsp; John Doe, you are now registered.
    Hello &nbsp; Mr &nbsp; John Doe, your phone number is &nbsp; 555-555-555 &nbsp;
    Test: &euro;/&eacute;</p>"
string(107) "Hello Mr John Doe, you are now registered. Hello Mr John Doe, your phone number is 555-555-555 Test: €/é"