Search Results

Search found 19474 results on 779 pages for 'xml validation'.

Page 37/779 | < Previous Page | 33 34 35 36 37 38 39 40 41 42 43 44  | Next Page >

  • Problem with user login validation by authlogic

    - by Andrei
    Hi, I want to use email for signing in, and to allow users to have similar names. One way to do this is to rename login/username field to something different. However, I want to do it just by setting up authlogic. I tried the following acts_as_authentic do |c| c.login_field :email c.validate_login_field false c.validate_email_field true end but it still complains that the login already exists. What must be done to avoid username validation without renaming the field?

    Read the article

  • jQuery Validation Plugin: Packer undefined error?

    - by Rosarch
    I'm using the jQuery validation plugin from bassistance.de. It works fine. From <head>: <script type="text/javascript" src="/static/JQuery.js"></script> <script type="text/javascript" src="/static/js-lib/jquery.validate.pack.js"></script> <script type="text/javascript" src="/static/js-lib/jquery.validate.additional-methods.js"></script> At first, this was the only validation code I had, and it worked: $("form").validate(); $("#form-username").rules("add", { required: true, email: true, }); It was validating this HTML: <form id="form-username-form" action="api/user_of_email" method="get"> <p> <label for="form-username">Email:</label> <input type="text" name="email" id="form-username" /> <input type="submit" value="Submit" id="form-submit" /> </p> </form> Great, everything works. But then I add this JS: $("#form-choose-options input[type='text']").rules("add", { number: true, }); to validate this markup: <form id="form-choose-options" action="api/set_options" method="get"> <p> <label for="form-min-credits">Min credits per term:</label><input type="text" name="min_credits" id="form-min-credits" /> <br /> <label for="form-optimal-credits">Optimal credits per term:</label><input type="text" name="optimal_credits" id="form-optimal-credits" /> <br /> <label for="form-max-credits">Max credits per term:</label><input type="text" name="max_credits" id="form-max-credits" /> <br /> <label for="form-low-GPA">Lowest acceptable GPA:</label><input type="text" name="low_GPA" id="form-low-GPA" /> <br /> <label for="form-high-GPA">Highest realistic GPA:</label><input type="text" name="high_GPA" id="form-high-GPA" /> <br /> <input type="hidden" class="user-pk" name="pk"/> <input type="submit" value="Submit" /> </p> </form> This causes a javascript error on document load: $.data(f.form, "validator") is undefined The error is from the packer function. What am I doing wrong?

    Read the article

  • jQuery + Dialog Form Validation

    - by Panther24
    Hi, I have a jQuery Dialog form and on submit I'm trying to validate the fields. I'm using http://docs.jquery.com/Plugins/Validation to validate. In this I'm facing an issue, the validate function is not being called. I'm posting some snippet of my code $("#register-dialog-form").dialog({ autoOpen: false, height: 350, width: 450, modal: true, buttons: { 'Register': function() { $("#registerFrm").validate({ rules: { accountid: "required", name: { required: true, minlength: 5 }, username: { required: true, minlength: 5 }, password: { required: true, minlength: 5 } }, messages: { firstname: "Please enter your firstname", accountid: "Please enter the lastname", name: "Please enter a user friendly name", username: { required: "Please enter a username", minlength: jQuery.format("Enter at least {0} characters") }, password: { required: "Please provide a password", minlength: jQuery.format("Password must be at least {0} characters long") } } }); //****************** //TODO: Need to submit my form here //****************** $(this).dialog('close'); }, Cancel: function() { $(this).dialog('close'); } }, close: function() { //$('registerFrm').clearForm(); } }); Can someone please tell me what I'm doing wrong here. I've also tried to put the validation into $(document).ready(function() {}, but with no success. Here is the html code <div id="register-dialog-form" title="Register Account - Master" align="center" style="display: none"> <s:form name="registerFrm" id="registerFrm" action="registermaster" method="POST"> <table width="90%" border="0" class="ui-widget"> <tr> <td> <s:textfield label="Account Id" name="accountid" id="accountid" cssClass="text ui-widget-content ui-corner-all" /> </td> </tr> <tr> <td> <s:textfield label="Name" name="name" id="name" cssClass="text ui-widget-content ui-corner-all" /> </td> </tr> <tr> <td> <s:textfield label="Username" name="username" id="username" cssClass="text ui-widget-content ui-corner-all" /> </td> </tr> <tr> <td> <s:password label="Password" name="password" id="password" cssClass="text ui-widget-content ui-corner-all" /> </td> </tr> </table> </s:form> </div><!--End of RegisterAcc form-->

    Read the article

  • Jquery validation on click event instead of on submit

    - by Mazzi
    I looked all around SOF but no luck to find me answer. It is either too easy or the answer is not just there. What I simply need to do is to validate the form when my <img id='submit'/> is clicked and submit it afterwards. $(document).ready(function(){ $('#submit').click(function() { }); // Validation $('#suzuki_scb').validate({ // My Rules and Messages! }); });

    Read the article

  • jQuery Validation help

    - by Cameron
    If you look here: http://creathive.net you will see I have an application form down at the bottom of the page and I have added some jQuery validation to make a user fills it out correctly. However what I would like to do is instead of showing all those labels next to the input boxes (which breaks the layout) is just keep it simple and only change the colours of the input fields. How do I do this? Thanks.

    Read the article

  • odd validation error messages with authlogic

    - by peter
    i have an issue where when validation fails, i get messages like "{{count}} errors prohibited this {{model}} from being saved" and "{{attribute}} {{message}}". it looks like something isn't getting expanded correctly. i've tried adding validates_* stuff but it doesn't seem to help. i've also tried to search the web for an answer but when i add the '{{' and '}}' i get no results. what am i missing? how can i fix this? thanks, -peter

    Read the article

  • Validation Control

    - by James
    I placed some validation controls on my grid view template. The only problem is that it is taking a lot of space vertically. Is there a property to set to solve this problem?

    Read the article

  • CodeIgniter Form Validation

    - by mmcglynn
    I am trying to set up validation on a simple contact form that is created using the form helper. No validation at all occurs. What is wrong? In the code below, the “good” keyword always shows, regardless of what is entered into the form, and the saved values set via set_value are never shown. Controller // Contact function contact() { $data['pageTitle'] = "Contact"; $data['bodyId'] = "contact"; $this->load->library('form_validation'); $config_rules = array ('email' => 'required','message' => 'required'); $this->form_validation->set_rules($config_rules); if ($this->form_validation->run() == FALSE) { echo "bad"; $data['include'] = "v_contact"; $this->load->view('v_template',$data); } else { echo "good"; $data['include'] = "v_contact"; $this->load->view('v_template',$data); } } View echo validation_errors(); echo form_open('events/contact'); // name echo form_label('Name', 'name'); $data = array ( 'name' => 'name', 'id' => 'name', 'maxlength' => '64', 'size' => '40', 'value' => set_value('name') ); echo form_input($data) . "\n<br />"; // email address echo form_label('Email Address', 'email'); $data = array ( 'name' => 'email', 'id' => 'email', 'maxlength' => '64', 'size' => '40', 'value' => set_value('email') ); echo form_input($data) . "\n<br />"; // message echo form_label('Message', 'message'); $data = array ( 'name' => 'message', 'id' => 'message', 'rows' => '8', 'cols' => '35', 'value' => set_value('message') ); echo form_textarea($data) . "\n<br />"; echo form_submit('mysubmit', 'Send Message'); echo form_close();

    Read the article

  • Ruby on rails form validation issue

    - by Anooj
    Am pretty new to ROR. Need help in Rails form validation. Hey, am using rails 2.3.5 I have a basic validates_presence_of for the fields in the form. Now when i don't enter field details, i do get an error, but the error is displayed as: {{count}} errors prohibited this {{model}} from being saved There were problems with the following fields: {{attribute}} {{message}} {{attribute}} {{message}} Any help will be highly appreciated.

    Read the article

  • From client, force whole page validation

    - by George
    I have an ASP button for which I have set the OnClientClick property to display a javascript confirm message. However, I only want this message to be displayed AFTER all of the client side validations have passed. How can I do this? Essentially, I believe that I need to force Page level validation from the client and then, only if it passes, display the confirmation box.

    Read the article

  • j query validation plugin for two fields

    - by jonathan p
    I am using the Jquery Validation plug-in, however i need to add a "custom rule", i have 2 date fields and i need to ensure that the end date is not less than the start date. My problem is how to pass the two fields in as elements. As i understand u set up a custom function something like this : function customValidationMethod(value, element, params){ } But can't see how i could use it with two fields, if anyone has any ideas it would be greatly appreciated.

    Read the article

  • remove field name from object validation message

    - by Colin G
    I've got a simple active record validation on an object using this within a form: form.error_messages({:message => '', :header_message => ''}) This in turn outputs something like "FieldName My Custom message" What i need to do is remove the field name from the error message but leave my custom message. Can anyone point me in the right direction for this.

    Read the article

  • quick validation method...

    - by pradeep
    hi guys....i have a form with 20 fields .. i have 2 options ...one to validate on client side and another on click of submit button do a validation from server side using ajax and show result..... which 1 to choose...which is faster server side or client side.. i am developing a application ..its not a website.

    Read the article

  • Validation library for PHP/mysql

    - by Industrial
    Hi! Is there any lightweight validation library available for PHP that easily can check if a specific string or value is valid for a known database type - Something like this: if (is_MEDIUMINT($var)) { $this->db->insert($anothervar); } Thanks!

    Read the article

  • Registration form validation not validating

    - by jgray
    I am a noob when it comes to web development. I am trying to validate a registration form and to me it looks right but it will not validate.. This is what i have so far and i am validating through a repository or database. Any help would be greatly appreciated. thanks <?php session_start(); $title = "User Registration"; $keywords = "Name, contact, phone, e-mail, registration"; $description = "user registration becoming a member."; require "partials/_html_header.php"; //require "partials/_header.php"; require "partials/_menu.php"; require "DataRepository.php"; // if all validation passed save user $db = new DataRepository(); // form validation goes here $first_nameErr = $emailErr = $passwordErr = $passwordConfirmErr = ""; $first_name = $last_name = $email = $password = $passwordConfirm = ""; if(isset($_POST['submit'])) { $valid = TRUE; // check if all fields are valid { if ($_SERVER["REQUEST_METHOD"] == "POST") { if (empty($_POST["first_name"])) {$first_nameErr = "Name is required";} else { // $first_name = test_input($_POST["first_name"]); // check if name only contains letters and whitespace if (!preg_match("/^[a-zA-Z ]*$/",$first_name)) { $first_nameErr = "Only letters and white space allowed"; } } if (empty($_POST["email"])) {$emailErr = "Email is required";} else { // $email = test_input($_POST["email"]); // check if e-mail address syntax is valid if (!preg_match("/([\w\-]+\@[\w\-]+\.[\w\-]+)/",$email)) { $emailErr = "Invalid email format"; } } if (!preg_match("/(......)/",$password)) { $passwordErr = "Subject must contain THREE or more characters!"; } if ($_POST['password']!= $_POST['passwordConfirm']) { echo("Oops! Password did not match! Try again. "); } function test_input($data) { $data = trim($data); $data = stripslashes($data); $data = htmlspecialchars($data); return $data; } } } if(!$db->isEmailUnique($_POST['email'])) { $valid = FALSE; //display errors in the correct places } // if still valid save the user if($valid) { $new_user = array( 'first_name' => $_POST['first_name'], 'last_name' => $_POST['last_name'], 'email' => $_POST['email'], 'password' => $_POST['password'] ); $results = $db->saveUser($new_user); if($results == TRUE) { header("Location: login.php"); } else { echo "WTF!"; exit; } } } ?> <head> <style> .error {color: #FF0000;} </style> </head> <h1 class="center"> World Wide Web Creations' User Registration </h1> <p><span class="error"></span><p> <form method="POST" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>" onsubmit="return validate_form()" > First Name: <input type="text" name="first_name" id="first_name" value="<?php echo $first_name;?>" /> <span class="error"> <?php echo $first_nameErr;?></span> <br /> <br /> Last Name(Optional): <input type="text" name="last_name" id="last_name" value="<?php echo $last_name;?>" /> <br /> <br /> E-mail: <input type="email" name="email" id="email" value="<?php echo $email;?>" /> <span class="error"> <?php echo $emailErr;?></span> <br /> <br /> Password: <input type="password" name="password" id="password" value="" /> <span class="error"> <?php echo $passwordErr;?></span> <br /> <br /> Confirmation Password: <input type="password" name="passwordConfirm" id="passwordConfirm" value="" /> <span class="error"> <?php echo $passwordConfirmErr;?></span> <br /> <br /> <br /> <br /> <input type="submit" name="submit" id="submit" value="Submit Data" /> <input type="reset" name="reset" id="reset" value="Reset Form" /> </form> </body> </html> <?php require "partials/_footer.php"; require "partials/_html_footer.php"; ?> class DataRepository { // version number private $version = "1.0.3"; // turn on and off debugging private static $debug = FALSE; // flag to (re)initialize db on each call private static $initialize_db = FALSE; // insert test data on initialization private static $load_default_data = TRUE; const DATAFILE = "203data.txt"; private $data = NULL; private $errors = array(); private $user_fields = array( 'id' => array('required' => 0), 'created_at' => array('required' => 0), 'updated_at' => array('required' => 0), 'first_name' => array('required' => 1), 'last_name' => array('required' => 0), 'email' => array('required' => 1), 'password' => array('required' => 1), 'level' => array('required' => 0, 'default' => 2), ); private $post_fields = array( 'id' => array('required' => 0), 'created_at' => array('required' => 0), 'updated_at' => array('required' => 0), 'user_id' => array('required' => 1), 'title' => array('required' => 1), 'message' => array('required' => 1), 'private' => array('required' => 0, 'default' => 0), ); private $default_user = array( 'id' => 1, 'created_at' => '2013-01-01 00:00:00', 'updated_at' => '2013-01-01 00:00:00', 'first_name' => 'Admin Joe', 'last_name' => 'Tester', 'email' => '[email protected]', 'password' => 'a94a8fe5ccb19ba61c4c0873d391e987982fbbd3', 'level' => 1, ); private $default_post = array( 'id' => 1, 'created_at' => '2013-01-01 00:00:00', 'updated_at' => '2013-01-01 00:00:00', 'user_id' => 1, 'title' => 'My First Post', 'message' => 'This is the message of the first post.', 'private' => 0, ); // constructor will load existing data into memory // if it does not exist it will create it and initialize if desired public function __construct() { // check if need to reset if(DataRepository::$initialize_db AND file_exists(DataRepository::DATAFILE)) { unlink(DataRepository::DATAFILE); } // if file doesn't exist, create the initial datafile if(!file_exists(DataRepository::DATAFILE)) { $this->log("Data file does not exist. Attempting to create it... (".__FUNCTION__.":".__LINE__.")"); // create initial file $this->data = array( 'users' => array( ), 'posts' => array() ); // load default data if needed if(DataRepository::$load_default_data) { $this->data['users'][1] = $this->default_user; $this->data['posts'][1] = $this->default_post; } $this->writeTheData(); } // load the data into memory for use $this->loadTheData(); } private function showErrors($break = TRUE, $type = NULL) { if(count($this->errors) > 0) { echo "<div style=\"color:red;font-weight: bold;font-size: 1.3em\":<h3>$type Errors</h3><ol>"; foreach($this->errors AS $error) { echo "<li>$error</li>"; } echo "</ol></div>"; if($break) { "</br></br></br>Exiting because of errors!"; exit; } } } private function writeTheData() { $this->log("Attempting to write the datafile: ".DataRepository::DATAFILE." (".__FUNCTION__.":".__LINE__.")"); file_put_contents(DataRepository::DATAFILE, json_encode($this->data)); $this->log("Datafile written: ".DataRepository::DATAFILE." (line: ".__LINE__.")"); } private function loadTheData() { $this->log("Attempting to load the datafile: ".DataRepository::DATAFILE." (".__FUNCTION__.":".__LINE__.")"); $this->data = json_decode(file_get_contents(DataRepository::DATAFILE), true); $this->log("Datafile loaded: ".DataRepository::DATAFILE." (".__FUNCTION__.":".__LINE__.")", $this->data); } private function validateFields(&$info, $fields, $pre_errors = NULL) { // merge in any pre_errors if($pre_errors != NULL) { $this->errors = array_merge($this->errors, $pre_errors); } // check all required fields foreach($fields AS $field => $reqs) { if(isset($reqs['required']) AND $reqs['required'] == 1) { if(!isset($info[$field]) OR strlen($info[$field]) == 0) { $this->errors[] = "$field is a REQUIRED field"; } } // set any default values if not present if(isset($reqs['default']) AND (!isset($info[$field]) OR $info[$field] == "")) { $info[$field] = $reqs['default']; } } $this->showErrors(); if(count($this->errors) == 0) { return TRUE; } else { return FALSE; } } private function validateUser(&$user_info) { // check if the email is already in use $this->log("About to check pre_errors: ".DataRepository::DATAFILE." (".__FUNCTION__.":".__LINE__.")", $user_info); $pre_errors = NULL; if(isset($user_info['email'])) { if(!$this->isEmailUnique($user_info['email'])) { $pre_errors = array('The email: '.$user_info['email'].' is already used in our system'); } } $this->log("After pre_error check: ".DataRepository::DATAFILE." (".__FUNCTION__.":".__LINE__.")", $pre_errors); return $this->validateFields($user_info, $this->user_fields, $pre_errors); } private function validatePost(&$post_info) { // check if the user_id in the post actually exists $this->log("About to check pre_errors: ".DataRepository::DATAFILE." (".__FUNCTION__.":".__LINE__.")", $post_info); $pre_errors = NULL; if(isset($post_info['user_id'])) { if(!isset($this->data['users'][$post_info['user_id']])) { $pre_errors = array('The posts must belong to a valid user. (User '.$post_info['user_id'].' does not exist in the data'); } } $this->log("After pre_error check: ".DataRepository::DATAFILE." (".__FUNCTION__.":".__LINE__.")", $pre_errors); return $this->validateFields($post_info, $this->post_fields, $pre_errors); } private function log($message, $data = NULL) { $style = "background-color: #F8F8F8; border: 1px solid #DDDDDD; border-radius: 3px; font-size: 13px; line-height: 19px; overflow: auto; padding: 6px 10px;"; if(DataRepository::$debug) { if($data != NULL) { $dump = "<div style=\"$style\"><pre>".json_encode($data, JSON_PRETTY_PRINT)."</pre></div>"; } else { $dump = NULL; } echo "<code><b>Debug:</b> $message</code>$dump<br />"; } } public function saveUser($user_info) { $this->log("Entering saveUser: (".__FUNCTION__.":".__LINE__.")", $user_info); $mydata = array(); $update = FALSE; // check for existing data if(isset($user_info['id']) AND $this->data['users'][$user_info['id']]) { $mydata = $this->data['users'][$user_info['id']]; $this->log("Loaded prior user: ".print_r($mydata, TRUE)." (".__FUNCTION__.":".__LINE__.")"); } // copy over existing values $this->log("Before copying over existing values: (".__FUNCTION__.":".__LINE__.")", $mydata); foreach($user_info AS $k => $v) { $mydata[$k] = $user_info[$k]; } $this->log("After copying over existing values: (".__FUNCTION__.":".__LINE__.")", $mydata); // check required fields if($this->validateUser($mydata)) { // hash password if new if(isset($mydata['password'])) { $mydata['password'] = sha1($mydata['password']); } // if no id, add the next available one if(!isset($mydata['id']) OR (int)$mydata['id'] < 1) { $this->log("No id set: ".DataRepository::DATAFILE." (".__FUNCTION__.":".__LINE__.")"); if(count($this->data['users']) == 0) { $mydata['id'] = 1; $this->log("Setting id to 1: ".DataRepository::DATAFILE." (".__FUNCTION__.":".__LINE__.")"); } else { $mydata['id'] = max(array_keys($this->data['users']))+1; $this->log("Found max id and added 1 [".$mydata['id']."]: ".DataRepository::DATAFILE." (".__FUNCTION__.":".__LINE__.")"); } } // set created date if null if(!isset($mydata['created_at'])) { $mydata['created_at'] = date ("Y-m-d H:i:s", time()); } // update modified time $mydata['modified_at'] = date ("Y-m-d H:i:s", time()); // copy into data and save $this->log("Before data save: (".__FUNCTION__.":".__LINE__.")", $this->data); $this->data['users'][$mydata['id']] = $mydata; $this->writeTheData(); } return TRUE; } public function getUserById($id) { if(isset($this->data['users'][$id])) { return $this->data['users'][$id]; } else { return array(); } } public function isEmailUnique($email) { // find the user that has the right username/password foreach($this->data['users'] AS $k => $v) { $this->log("Checking unique email: {$v['email']} == $email (".__FUNCTION__.":".__LINE__.")", NULL); if($v['email'] == $email) { $this->log("FOUND NOT unique email: {$v['email']} == $email (".__FUNCTION__.":".__LINE__.")", NULL); return FALSE; break; } } $this->log("Email IS unique: $email (".__FUNCTION__.":".__LINE__.")", NULL); return TRUE; } public function login($username, $password) { // hash password for validation $password = sha1($password); $this->log("Attempting to login with $username / $password: (".__FUNCTION__.":".__LINE__.")", NULL); $user = NULL; // find the user that has the right username/password foreach($this->data['users'] AS $k => $v) { if($v['email'] == $username AND $v['password'] == $password) { $user = $v; break; } } $this->log("Exiting login: (".__FUNCTION__.":".__LINE__.")", $user); return $user; } public function savePost($post_info) { $this->log("Entering savePost: (".__FUNCTION__.":".__LINE__.")", $post_info); $mydata = array(); // check for existing data if(isset($post_info['id']) AND $this->data['posts'][$post_info['id']]) { $mydata = $this->data['posts'][$post_info['id']]; $this->log("Loaded prior posts: ".print_r($mydata, TRUE)." (".__FUNCTION__.":".__LINE__.")"); } $this->log("Before copying over existing values: (".__FUNCTION__.":".__LINE__.")", $mydata); foreach($post_info AS $k => $v) { $mydata[$k] = $post_info[$k]; } $this->log("After copying over existing values: (".__FUNCTION__.":".__LINE__.")", $mydata); // check required fields if($this->validatePost($mydata)) { // if no id, add the next available one if(!isset($mydata['id']) OR (int)$mydata['id'] < 1) { $this->log("No id set: ".DataRepository::DATAFILE." (".__FUNCTION__.":".__LINE__.")"); if(count($this->data['posts']) == 0) { $mydata['id'] = 1; $this->log("Setting id to 1: ".DataRepository::DATAFILE." (".__FUNCTION__.":".__LINE__.")"); } else { $mydata['id'] = max(array_keys($this->data['posts']))+1; $this->log("Found max id and added 1 [".$mydata['id']."]: ".DataRepository::DATAFILE." (".__FUNCTION__.":".__LINE__.")"); } } // set created date if null if(!isset($mydata['created_at'])) { $mydata['created_at'] = date ("Y-m-d H:i:s", time()); } // update modified time $mydata['modified_at'] = date ("Y-m-d H:i:s", time()); // copy into data and save $this->data['posts'][$mydata['id']] = $mydata; $this->log("Before data save: (".__FUNCTION__.":".__LINE__.")", $this->data); $this->writeTheData(); } return TRUE; } public function getAllPosts() { return $this->loadPostsUsers($this->data['posts']); } public function loadPostsUsers($posts) { foreach($posts AS $id => $post) { $posts[$id]['user'] = $this->getUserById($post['user_id']); } return $posts; } public function dump($line_number, $temp = 'NO') { // if(DataRepository::$debug) { if($temp == 'NO') { $temp = $this->data; } echo "<pre>Dumping from line: $line_number\n"; echo json_encode($temp, JSON_PRETTY_PRINT); echo "</pre>"; } } } /* * Change Log * * 1.0.0 * - first version * 1.0.1 * - Added isEmailUnique() function for form validation and precheck on user save * 1.0.2 * - Fixed getAllPosts() to include the post's user info * - Added loadPostsUsers() to load one or more posts with their user info * 1.0.3 * - Added autoload to always add admin Joe. */

    Read the article

  • Decimal validation in server side textbox using C#

    - by V.V
    I use this code for decimal validation.It was working fine.but it allow to enter the alphabets into the text box when i exit from the text box the error message will show nearby textbox.I need,if i press the alphabets the text box doesn't allow to enter the text box , how to do this? <asp:RegularExpressionValidator ControlToValidate="txtNumber" runat="server" ValidationExpression="^[1-9]\d*(\.\d+)?$" ErrorMessage="Please enter only numbers"> </asp:RegularExpressionValidator>

    Read the article

  • Validation in Silverlight

    - by Timmy Kokke
    Getting started with the basics Validation in Silverlight can get very complex pretty easy. The DataGrid control is the only control that does data validation automatically, but often you want to validate your own entry form. Values a user may enter in this form can be restricted by the customer and have to fit an exact fit to a list of requirements or you just want to prevent problems when saving the data to the database. Showing a message to the user when a value is entered is pretty straight forward as I’ll show you in the following example.     This (default) Silverlight textbox is data-bound to a simple data class. It has to be bound in “Two-way” mode to be sure the source value is updated when the target value changes. The INotifyPropertyChanged interface must be implemented by the data class to get the notification system to work. When the property changes a simple check is performed and when it doesn’t match some criteria an ValidationException is thrown. The ValidatesOnExceptions binding attribute is set to True to tell the textbox it should handle the thrown ValidationException. Let’s have a look at some code now. The xaml should contain something like below. The most important part is inside the binding. In this case the Text property is bound to the “Name” property in TwoWay mode. It is also told to validate on exceptions. This property is false by default.   <StackPanel Orientation="Horizontal"> <TextBox Width="150" x:Name="Name" Text="{Binding Path=Name, Mode=TwoWay, ValidatesOnExceptions=True}"/> <TextBlock Text="Name"/> </StackPanel>   The data class in this first example is a very simplified person class with only one property: string Name. The INotifyPropertyChanged interface is implemented and the PropertyChanged event is fired when the Name property changes. When the property changes a check is performed to see if the new string is null or empty. If this is the case a ValidationException is thrown explaining that the entered value is invalid.   public class PersonData:INotifyPropertyChanged { private string _name; public string Name { get { return _name; } set { if (_name != value) { if(string.IsNullOrEmpty(value)) throw new ValidationException("Name is required"); _name = value; if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("Name")); } } } public event PropertyChangedEventHandler PropertyChanged=delegate { }; } The last thing that has to be done is letting binding an instance of the PersonData class to the DataContext of the control. This is done in the code behind file. public partial class Demo1 : UserControl { public Demo1() { InitializeComponent(); this.DataContext = new PersonData() {Name = "Johnny Walker"}; } }   Error Summary In many cases you would have more than one entry control. A summary of errors would be nice in such case. With a few changes to the xaml an error summary, like below, can be added.           First, add a namespace to the xaml so the control can be used. Add the following line to the header of the .xaml file. xmlns:Controls="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Data.Input"   Next, add the control to the layout. To get the result as in the image showed earlier, add the control right above the StackPanel from the first example. It’s got a small margin to separate it from the textbox a little.   <Controls:ValidationSummary Margin="8"/>   The ValidationSummary control has to be notified that an ValidationException occurred. This can be done with a small change to the xaml too. Add the NotifyOnValidationError to the binding expression. By default this value is set to false, so nothing would be notified. Set the property to true to get it to work.   <TextBox Width="150" x:Name="Name" Text="{Binding Name, Mode=TwoWay, ValidatesOnExceptions=True, NotifyOnValidationError=True}"/>   Data annotation Validating data in the setter is one option, but not my personal favorite. It’s the easiest way if you have a single required value you want to check, but often you want to validate more. Besides, I don’t consider it best practice to write logic in setters. The way used by frameworks like WCF Ria Services is the use of attributes on the properties. Instead of throwing exceptions you have to call the static method ValidateProperty on the Validator class. This call stays always the same for a particular property, not even when you change the attributes on the property. To mark a property “Required” you can use the RequiredAttribute. This is what the Name property is going to look like:   [Required] public string Name { get { return _name; } set { if (_name != value) { Validator.ValidateProperty(value, new ValidationContext(this, null, null){ MemberName = "Name" }); _name = value; if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("Name")); } } }   The ValidateProperty method takes the new value for the property and an instance of ValidationContext. The properties passed to the constructor of the ValidationContextclass are very straight forward. This part is the same every time. The only thing that changes is the MemberName property of the ValidationContext. Property has to hold the name of the property you want to validate. It’s the same value you provide the PropertyChangedEventArgs with. The System.ComponentModel.DataAnnotation contains eight different validation attributes including a base class to create your own. They are: RequiredAttribute Specifies that a value must be provided. RangeAttribute The provide value must fall in the specified range. RegularExpressionAttribute Validates is the value matches the regular expression. StringLengthAttribute Checks if the number of characters in a string falls between a minimum and maximum amount. CustomValidationAttribute Use a custom method to validate the value. DataTypeAttribute Specify a data type using an enum or a custom data type. EnumDataTypeAttribute Makes sure the value is found in a enum. ValidationAttribute A base class for custom validation attributes All of these will ensure that an validation exception is thrown, except the DataTypeAttribute. This attribute is used to provide some additional information about the property. You can use this information in your own code.   [Required] [Range(0,125,ErrorMessage = "Value is not a valid age")] public int Age {   It’s no problem to stack different validation attributes together. For example, when an Age is required and must fall in the range from 0 to 125:   [Required, StringLength(255,MinimumLength = 3)] public string Name {   Or in one row like this, for a required Name with at least 3 characters and a maximum of 255:   Delayed validation Having properties marked as required can be very useful. The only downside to the technique described earlier is that you have to change the value in order to get it validated. What if you start out with empty an empty entry form? All fields are empty and thus won’t be validated. With this small trick you can validate at the moment the user click the submit button.   <TextBox Width="150" x:Name="NameField" Text="{Binding Name, Mode=TwoWay, ValidatesOnExceptions=True, NotifyOnValidationError=True, UpdateSourceTrigger=Explicit}"/>   By default, when a TwoWay bound control looses focus the value is updated. When you added validation like I’ve shown you earlier, the value is validated. To overcome this, you have to tell the binding update explicitly by setting the UpdateSourceTrigger binding property to Explicit:   private void SubmitButtonClick(object sender, RoutedEventArgs e) { NameField.GetBindingExpression(TextBox.TextProperty).UpdateSource(); }   This way, the binding is in two direction but the source is only updated, thus validated, when you tell it to. In the code behind you have to call the UpdateSource method on the binding expression, which you can get from the TextBox.   Conclusion Data validation is something you’ll probably want on almost every entry form. I always thought it was hard to do, but it wasn’t. If you can throw an exception you can do validation. If you want to know anything more in depth about something I talked about in this article let me know. I might write an entire post to that.

    Read the article

  • Should all new web projects build their backend based on xml/json result sets?

    - by Blankman
    If you were building a new Saas project, would it make sense to start with all of the backend services returning xml/json? Because these days you need to build for both the web and mobile devices, and having a backend that is build from the start to return xml and json, you are ready to go mobile (all services have the business logic, so you won't be repeating anything). Now the web would be MVC, so the controller would just be routing the request to your service backend, and converting the json or xml to html. The obviousl downside is that you have to build a backend, and then another web project that calls your backend. But this also goes to you favor as it forces you to seperate your concerns, and not leak business logic in your controller/view layer. Thoughts?

    Read the article

< Previous Page | 33 34 35 36 37 38 39 40 41 42 43 44  | Next Page >