phpMyViews - Tutorial

Example 5 : Validation Example

phpMyViews also supports validation of form entries.

The following example has three actions:

The 'default' action which renders a table with a list of news entries.
The 'edit' action which allows editing one entry.
And finally the 'update_entry' action which writes the changed values from the 'edit' action to the database.

The last step has an additional attribute 'validate'. A file name is given of a simple PHP script which can perform some validation of the entered form data.


<?php
  # MySQL Parameters
  $pmv_db_host="host";
  $pmv_db_name="db";
  $pmv_db_user="user";
  $pmv_db_pass="pass";
  if (file_exists('pmv_db_config.php')) {
    include('pmv_db_config.php');
  }

  # Actions
  $pmv['default'][0]['sql']='SELECT newsID, newsDate, newsTopic FROM newsletter ORDER BY newsID DESC LIMIT 10';
  $pmv['default'][0]['pre']='<table>
        <tr><th>ID</th><th>Topic</th><th>Date</th><th></th></tr>';
  $pmv['default'][0]['main']='<tr><td>$newsID</td><td>$newsTopic</td><td>$newsDate</td><td>
        <form action="'.$PHP_SELF.'" method="post">
          <input type="hidden" name="msgid" value="$newsID">
          <input type="submit" name="pmv_action" value="edit">
        </form></td></tr>';
  $pmv['default'][0]['post']='</table>';

  $pmv['edit'][0]['sql']='SELECT * FROM newsletter WHERE newsID="$msgid"';
  $pmv['edit'][0]['main']='
        <form action="'.$PHP_SELF.'" method="POST">
          <table> 
            <tr><td>�berschrift:</td><td><input type="text" name="topic" size="60" maxlength="120" value="$newsTopic"></td></tr>
            <tr><td>Text:</td><td><textarea name="text" rows="10" cols="50">$newsText</textarea></td></tr>
          </table>
          <input type="hidden" name="pmv_action" value="update_entry">
          <input type="hidden" name="msgid" value="$newsID"><input type="submit" value="change">
        </form>';

  $pmv['update_entry'][0]['sql']='UPDATE newsletter SET newsTopic="$topic", newsText="$text" WHERE newsID=$msgid';
  $pmv['update_entry'][0]['post']='Done. <a href="'.$PHP_SELF.'">Back</a>';
  $pmv['update_entry'][0]['validate']='vali_newsletter.php';

  # execute phpMyViews
  //$path_to_pmv=$_SERVER['DOCUMENT_ROOT']."/phpmyviews.php";
  $path_to_pmv="phpmyviews.php";
  include $path_to_pmv;
?>

Let's have a look now on the validation script. Here comes the source code for this script:


<?php
function vali_newsletter($values) {
    $errors = array();
    if (strlen($values['topic'])==0) {
        $errors[] = "Topic must not be empty!";
    }
    if (strlen($values['text'])==0) {
        $errors[] = "Text must not be empty!";
    }
    if (count($errors)>0) {
        $errors[] = "Please go back and correct your inputs.";
    }
    return $errors;
}
?>

The script file must contain a function which is exactly named like the file.
This function will then be called with the form values stored in the $values variable.
This function will be called before the 'sql' command is executed!
The function must return an array. If no errors occurred and the validation succeeded, the array must be empty.
If any errors occurred, the $errors array should contain error messages which explain why the validation has failed. The user then has to go back and correct his form entry data.