How to validate node title field Drupal 7

Question

I want to add validation to the node title field. When the user enters the character X and submits the form they should get a message saying "you are not allowed to enter special character X".

Answer 1

You can setup field/property validations with the module Field validation.

Here's the documentation on how to add validation to properties (with the Field validation module), as the title isn't a field in Drupal 7.

Answer 2

Check these module Node Title Validation

These is very light weight module, and helps to validate node titles with min/max characters, Blacklist characters/words and unique node titles.

Answer 3

You can implement hook_node_validate() and check the special character in node title.

function MYMODULE_node_validate($node, $form, $form_state){
 // special character list, Add more special character if you want.
 $special_character_list = '[\'^£$%&*()}{@#~?><>,|=_+¬-]'; 
 if(preg_match('/' . $special_character_list . '/', $node->title) !== 0){
   form_set_error('title', 'Special character are not allowed in form title.')
 }
}

UPDATE :

function MYMODULE_node_validate($node, $form, $form_state){
  // special character list, Add more special character if you want, escape the character if required.
  $special_character_list = '\'^£$%&*()}{@#~?><>,|=_+¬\-\[\]';
  if(preg_match('/[' . $special_character_list . ']/', $node->title) !== 0){
    form_set_error('title', t("Special characters !special_character_list are not allowed in title.", array('!special_character_list' => $special_character_list)));
  }
 }

Answer 4

I had the same problem, field validation module work correctly for another field but when I want to validate title I can't validate it and finally find the Title module ,
Usage

After enabling the module as usual, visit the Manage fields page of the content type, taxonomy vocabulary or "comment type" which you wish to replace fields of and click the replace link. That's all.

after installing this module go to your field management and see "Replace" beside title , with this feature, it convert drupal default title and after converting you can work with field title like another fields. I hope this help you and future guys that have the same problem.