Zend Framework by examples (ZfEx): Validate a text

In this example, we implement text validation. Validators are chained together. We also implement custom validations.

Components used in this example

MyValidate MyLowerCaseValidator MyUpperCaseValidator MyHtml Entry point HTML | Try it | View source code

Implementation of the validation process

We define the list of Zend validators. We exclude some validators where parameters are needed. We also exclude the validators for databases.
We define the list of custom validators.
We define hard coded values for some numeric validators.
We define hard coded values for the validators for files.


class MyValidate
{
    // We define the list of Zend validators.
    // We exclude some validators where parameters are needed.
    // We also exclude the validators for databases.
    public $zendValidators = array(
        'Zend_Validate_Alnum',
        'Zend_Validate_Alpha',
        // 'Zend_Validate_Barcode',
        'Zend_Validate_Barcode_Ean13',
        'Zend_Validate_Barcode_UpcA',
        'Zend_Validate_Between',
        'Zend_Validate_Ccnum',
        'Zend_Validate_Date',
        // 'Zend_Validate_Db_NoRecordExists',
        // 'Zend_Validate_Db_RecordExists',
        'Zend_Validate_Digits',
        'Zend_Validate_EmailAddress',
        // 'Zend_Validate_File_Count',
        'Zend_Validate_File_Crc32',
        // 'Zend_Validate_File_ExcludeExtension',
        // 'Zend_Validate_File_ExcludeMimeType',
        // 'Zend_Validate_File_Exists',
        'Zend_Validate_File_Extension',
        'Zend_Validate_File_FilesSize',
        // 'Zend_Validate_File_Hash',
        // 'Zend_Validate_File_ImageSize',
        // 'Zend_Validate_File_IsCompressed',
        // 'Zend_Validate_File_IsImage',
        'Zend_Validate_File_Md5',
        // 'Zend_Validate_File_MimeType',
        // 'Zend_Validate_File_NotExists',
        'Zend_Validate_File_Sha1',
        'Zend_Validate_File_Size',
        // 'Zend_Validate_File_Upload',
        'Zend_Validate_File_WordCount',
        'Zend_Validate_Float',
        'Zend_Validate_GreaterThan',
        'Zend_Validate_Hex',
        'Zend_Validate_Hostname',
        'Zend_Validate_Iban',
        'Zend_Validate_Identical',
        // 'Zend_Validate_InArray',
        'Zend_Validate_Int',
        'Zend_Validate_Ip',
        'Zend_Validate_LessThan',
        'Zend_Validate_NotEmpty',
        // 'Zend_Validate_Regex',
        // 'Zend_Validate_Sitemap_Changefreq',
        // 'Zend_Validate_Sitemap_Lastmod',
        // 'Zend_Validate_Sitemap_Loc',
        // 'Zend_Validate_Sitemap_Priority',
        // 'Zend_Validate_StringLength',
    );

    // We define the list of custom validators.
    public $customValidators = array(
        'MyLowerCaseValidator',
        'MyUpperCaseValidator',
    );

    public $min;
    public $max;
    public $crc32;
    public $extension;
    public $size;
    public $md5;
    public $sha1;
    public $wordCount;
    public $identical;

    public function __construct()
    {
        // We define hard coded values for some numeric validators.
        $this->min = 10;
        $this->max = 20;

        // We define hard coded values for the validators for files.
        $this->crc32 = hash_file('CRC32', __FILE__);
        $info = pathinfo(__FILE__);
        $this->extension = $info['extension'];
        $this->size = filesize(__FILE__);
        $this->md5 = hash_file('MD5', __FILE__);
        $this->sha1 = hash_file('SHA1', __FILE__);
        $this->wordCount = str_word_count(file_get_contents(__FILE__));
        $this->identical = 'identical';
    }

Text validation

We get the text and the validators, from the GET request.
We instantiate the validator chain.
If the validator is a numeric validator, we instantiate the validator with one or more target values.
If the validator is a validator for files, we instantiate the validator and we use this file as a target.
We update the template of the error message for the file size, because we only validate for the exact size.
And we perform the validation.
If this is another validator, we simply add the validator.
And we perform the validation if it has not been done yet.
We return the error message if the validation failed.
If we catch an exception, we return the error message.


    public function process()
    {
        // We get the text and the validators, from the GET request.
        list($data, $validators) = $this->_getParameters();

        try {
            if (empty($validators)) {
                $result = 'Please enter some text and select one or more validators!';
            } else {
                // We instantiate the validator chain.
                $validatorChain = new Zend_Validate();

                foreach($validators as $validator) {
                    switch ($validator) {
                        // If the validator is a numeric validator, we instantiate the validator
                        // with one or more target values.
                        case 'Zend_Validate_GreaterThan':
                        case 'Zend_Validate_LessThan':
                            $validatorChain->addValidator(new $validator($this->min));
                            break;

                        case 'Zend_Validate_Between':
                            $validatorChain->addValidator(new $validator($this->min, $this->max, false));
                            break;

                        // If the validator is a validator for files, we instantiate the validator
                        // and we use this file as a target.
                        case 'Zend_Validate_File_FilesSize':
                        case 'Zend_Validate_File_Size':
                        case 'Zend_Validate_File_WordCount':
                            // We update the template of the error message for the file size,
                            // because we only validate for the exact size.
                            $message = "Wrong value for file '%value%' but '%size%' detected";
                            // break;

                        case 'Zend_Validate_File_Crc32':
                        case 'Zend_Validate_File_Extension':
                        case 'Zend_Validate_File_Md5':
                        case 'Zend_Validate_File_Sha1':
                            $fileValidator = new $validator($data);
                            empty($message) or $fileValidator->setMessage($message);
                            $validatorChain->addValidator($fileValidator);
                            // And we perform the validation.
                            $isValid = $validatorChain->isValid(__FILE__);
                            break;

                        case 'Zend_Validate_Identical':
                            $validatorChain->addValidator(new $validator($this->identical));
                            break;

                        default:
                            // If this is another validator, we simply add the validator.
                            $validatorChain->addValidator(new $validator());
                    }
                }

                // And we perform the validation if it has not been done yet.
                isset($isValid) or $isValid = $validatorChain->isValid($data);

                if ($isValid) {
                    $result = 'Your text is valid!';
                } else {
                    // We return the error message if the validation failed.
                    $result = $validatorChain->getMessages();
                    $result = str_replace(__FILE__, basename(__FILE__), $result);
                }
            }

        } catch (Exception $e) {
            // If we catch an exception, we return the error message.
            $result = $e->getMessage();
        }

        $validators = array_pad($validators, 3, null);

        return array($data, $validators, $result);
    }

Extraction of the parameters from the GET request

We ignore a validator if the validator is invalid.


    private function _getParameters()
    {
        $data = isset($_GET['data'])? $_GET['data'] : null;

        // We ignore a validator if the validator is invalid.
        $validators = array();
        if (isset($_GET['validators'])) {
            foreach($_GET['validators'] as $validator) {
                (in_array($validator, $this->zendValidators) or
                in_array($validator, $this->customValidators)) and
                $validators[] = $validator;
            }
        }

        return array($data, $validators);
    }

Creation of a validator for lower case strings


class MyLowerCaseValidator extends Zend_Validate_Abstract
{
    const LOWER_CASE = 'lowerCase';

    protected $_messageTemplates = array(
        self::LOWER_CASE => "'%value%' is not a lower case string",
    );

    public function isValid($value)
    {
        $this->_setValue($value);

        if (strtolower($value) != $value) {
            $this->_error();
            return false;
        }

        return true;
    }

Creation of a validator for upper case strings


class MyUpperCaseValidator extends Zend_Validate_Abstract
{
    const UPPER_CASE = 'upperCase';

    protected $_messageTemplates = array(
        self::UPPER_CASE => "'%value%' is not an upper case string",
    );

    public function isValid($value)
    {
        $this->_setValue($value);

        if (strtoupper($value) != $value) {
            $this->_error();
            return false;
        }

        return true;
    }

Displaying items


class MyHtml
{

Displaying the title of the page based on the file name.


    public static function printTitle()
    {
        $basename = basename(__FILE__, '.php');
        $title = ucwords(str_replace('-' , ' ', $basename));
        $zfVersion = Zend_Version::VERSION;
        $phpVersion = phpversion();
        echo "ZfEx $title (ZF/$zfVersion PHP/$phpVersion)";
    }

Displaying the selected option


    public static function printSelected($value, $target)
    {
        $value == $target and print 'selected="selected"';
    }

Displaying a string or an array

If the data is an array, we convert the array into a set of lines.
We converts special characters into HTML entities.
We convert new-line characters into line breaks.


    public static function display($mixed, $isNl2Br = true, $isStripslashes = true)
    {
        // If the data is an array, we convert the array into a set of lines.
        is_array($mixed) and $mixed = implode("\n", $mixed);
        $isStripslashes and $mixed = stripslashes($mixed);
        // We converts special characters into HTML entities.
        $mixed = htmlspecialchars($mixed, ENT_QUOTES, 'UTF-8');
        // We convert new-line characters into line breaks.
        $isNl2Br and $mixed = nl2br($mixed);
        echo $mixed;
    }

Validating the text

We apply the validators to the text and we get all the parameters and the result, to display in the form.


// We apply the validators to the text and we get all the parameters and the result,
// to display in the form.
$validate = new MyValidate();
list($data, $validators, $result) = $validate->process();


<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title><?php MyHtml::printTitle();?></title>
    <style type="text/css">
      body, td {
          font-family: arial, sans-serif;
          font-size: 0.9em;
      }
      textarea.data {
          height: 3em;
          width: 30em;
      }
    </style>
  </head>

  <body>

    <p>EXAMPLE <?php MyHtml::printTitle();?></p>
    <hr />

    <form name="form">

      <table>

        <tr>
          <td>Text</td>
          <td><textarea class="data" name="data"><?php MyHtml::display($data, false);?></textarea>
          </td>
        </tr>

        <tr><td>&nbsp;</td></tr>

        <tr>
          <td>Validator Chain</td>
          <td>
            <select name="validators[0]">
              <option></option>
              <optgroup label="Zend Validators">
                <?php foreach($validate->zendValidators as $name) :?>
                    <option value="<?php echo $name;?>"
                            <?php MyHtml::printSelected($validators[0], $name);?>>
                      <?php echo $name;?>
                    </option>
                <?php endforeach;?>
              </optgroup>
              <optgroup label="Custom Validators">
                <?php foreach($validate->customValidators as $name) :?>
                    <option value="<?php echo $name;?>"
                            <?php MyHtml::printSelected($validators[0], $name);?>>
                      <?php echo $name;?>
                    </option>
                <?php endforeach;?>
              </optgroup>
            </select>
          </td>
        </tr>

        <tr>
          <td></td>
          <td>
            <select name="validators[1]">
              <option></option>
              <optgroup label="Zend Validators">
                <?php foreach($validate->zendValidators as $name) :?>
                    <option value="<?php echo $name;?>"
                            <?php MyHtml::printSelected($validators[1], $name);?>>
                      <?php echo $name;?>
                    </option>
                <?php endforeach;?>
              </optgroup>
              <optgroup label="Custom Validators">
                <?php foreach($validate->customValidators as $name) :?>
                    <option value="<?php echo $name;?>"
                            <?php MyHtml::printSelected($validators[1], $name);?>>
                      <?php echo $name;?>
                    </option>
                <?php endforeach;?>
              </optgroup>
            </select>
          </td>
        </tr>

        <tr>
          <td></td>
          <td>
            <select name="validators[2]">
              <option></option>
              <optgroup label="Zend Validators">
                <?php foreach($validate->zendValidators as $name) :?>
                    <option value="<?php echo $name;?>"
                            <?php MyHtml::printSelected($validators[2], $name);?>>
                      <?php echo $name;?>
                    </option>
                <?php endforeach;?>
              </optgroup>
              <optgroup label="Custom Validators">
                <?php foreach($validate->customValidators as $name) :?>
                    <option value="<?php echo $name;?>"
                            <?php MyHtml::printSelected($validators[2], $name);?>>
                      <?php echo $name;?>
                    </option>
                <?php endforeach;?>
              </optgroup>
           </select>
          </td>
        </tr>

        <tr><td>&nbsp;</td></tr>

        <tr>
          <td></td>
          <td>
            <input type="submit" value="Submit" />
            <br /> <br />
            Zend_Validate_Between is hard coded to validate numbers strictly
              between <?php echo $validate->min;?> and <?php echo $validate->max;?>. <br />
            Zend_Validate_Ccnum validate card numbers,
              for example 4539 9920 4349 1562. <br />
            Zend_Validate_File_Crc32 is hard coded to validate the CRC32 of this file
              which is <?php echo $validate->crc32;?>.<br>
            Zend_Validate_File_Extension is hard coded to validate the extension of this file
              which is <?php echo $validate->extension;?>.<br>
            Zend_Validate_File_FilesSize is hard coded to validate the size of this file
              which is <?php echo $validate->size;?>.<br>
            Zend_Validate_File_Md5 is hard coded to validate the MD5 of this file
              which is <?php echo $validate->md5;?>.<br>
            Zend_Validate_File_Sha1 is hard coded to validate the SHA1 of this file
              which is <?php echo $validate->sha1;?>.<br>
            Zend_Validate_File_Size is hard coded to validate the size of this file
              which is <?php echo $validate->size;?>.<br>
            Zend_Validate_File_WordCount is hard coded to validate the word count of this file
              which is <?php echo $validate->wordCount;?>.<br>
            Zend_Validate_GreaterThan is hard coded to validate numbers
              greater than <?php echo $validate->min;?>. <br />
            Zend_Validate_Iban validate International Bank Account Number,
              for example GB35MIDL40253432144670. <br />
            Zend_Validate_Identical is hard coded to validate
              the word <?php echo $validate->identical;?>. <br />
            Zend_Validate_LessThan is hard coded to validate numbers
              less than <?php echo $validate->min;?>. <br />
          </td>
        </tr>

      </table>
    </form>

    <hr />
    RESULT
    <br /> <br />
    <?php MyHtml::display($result, true, false);?>

  </body>
</html>