Adding a php contact form feature.

README.md

@@ -96,6 +96,15 @@ params:
 ```
 
 
+## Contact form
+
+If your server support php with the mail() command (very common) you can use the included contact form feature to get a contact form for your site.
+
+1. Copy the file `themes/zen/static/php/contact.php.example` to `static/php/contact.php`.
+2. Edit the contact.php file so it has your own e-mail address. You may also change the mail subject prefix.
+3. Add the shortcode `{{< contact >}}` to a page. Also set `contactform: true` in the front matter for that page so the contact.js file gets loaded.
+
+
 ## Dates
 
 If "lastmod" is set in the frontmatter on a post that value will be used in the "submitted" section. If not "date" is used.
@@ -105,6 +114,14 @@ With "lastmod" set a date section will also appear at the bottom of post telling
 
 ## Shortcodes
 
+### Contact
+
+Insert a html5 contact form, see more above.
+
+```
+{{< contact >}}
+```
+
 ### Figure
 
 Zen comes with a improved version of the built in "figure" shortcut.

layouts/shortcodes/contact.html

@@ -0,0 +1,16 @@
+<p class="contact-no-js error message">{{ i18n "contact_js" }}</p>
+<p class="contact-submitted status message hidden">{{ i18n "contact_submitted" }}</p>
+<p class="contact-error error message hidden">{{ i18n "contact_error" }}</p>
+
+<form class="contact-form hidden" action="#" method="post" accept-charset="UTF-8">
+  <label for="edit-name">{{ i18n "contact_name" }}</label>
+  <input type="text" id="edit-name" name="name" placeholder="{{ i18n "contact_name_placeholder" }}" tabindex="1" required autofocus><span></span>
+  <label for="edit-mail">{{ i18n "contact_mail" }}</label>
+  <input type="email" id="edit-mail" name="email" placeholder="{{ i18n "contact_mail_placeholder" }}" tabindex="2" required><span></span>
+  <input type="text" id="edit-url" class="hidden" name="url" placeholder="{{ i18n "contact_honypot" }}">
+  <label for="edit-subject">{{ i18n "contact_subject" }}</label>
+  <input type="text" id="edit-subject" name="subject" placeholder="{{ i18n "contact_subject_placeholder" }}" tabindex="3" required><span></span>
+  <label for="edit-message">{{ i18n "contact_message" }}</label>
+  <textarea id="edit-message" name="message" rows="5" placeholder="{{ i18n "contact_message_placeholder" }}" tabindex="4" required></textarea><span></span>
+  <button type="submit" name="submit" class="form-submit" disabled>{{ i18n "contact_submit" }}</button>
+</form>

static/js/contact.js

@@ -0,0 +1,56 @@
+/**
+ * @file
+ * A JavaScript file for the contact form.
+ */
+
+(function ($) {
+
+  'use strict';
+
+  // Contact form.
+  $('.contact-form').each(function () {
+    var $contact_form = $(this);
+    var $contact_button = $contact_form.find('.form-submit');
+    var contact_action = '/php/contact.php';
+
+    // Display the hidden form.
+    $contact_form.removeClass('hidden');
+    // Remove the "no javascript" messages
+    $('.contact-no-js').detach();
+
+    // Wait for a mouse to move, indicating they are human.
+    $('body').mousemove(function() {
+      // Unlock the form.
+      $contact_form.attr('action', contact_action);
+      $contact_button.attr('disabled', false);
+    });
+
+    // A tab or enter key pressed can also indicate they are human.
+    $('body').keydown(function(e) {
+      if ((e.keyCode == 9) || (e.keyCode == 13)) {
+        // Unlock the form.
+        $contact_form.attr('action', contact_action);
+        $contact_button.attr('disabled', false);
+      }
+    });
+
+    // Mark the form as submitted.
+    $contact_button.on('click touchstart MSPointerDown', function () {
+      $contact_form.addClass('js-submitted');
+    });
+
+    // Display messages.
+    if (location.search.substring(1) != '') {
+      switch(location.search.substring(1)) {
+        case 'submitted':
+          $('.contact-submitted').removeClass('hidden');
+          break;
+
+        case 'error':
+          $('.contact-error').removeClass('hidden');
+          break;
+      }
+    }
+  });
+
+})(jQuery);

static/php/contact.php.example

@@ -0,0 +1,98 @@
+<?php
+
+// Set the e-mail address that submission should be sent to.
+$address = 'info@example.com';
+
+// Set the e-mail subject prefix.
+$prefix = 'Website feedback';
+
+// DO NOT EDIT ANYTHING BELOW UNLESS YOU KNOW WHAT YOU ARE DOING.
+
+$error = false;
+$success = false;
+
+// Check that the submission address is valid.
+if ((bool) filter_var(trim($address), FILTER_VALIDATE_EMAIL)) {
+  // Also set sender/return path header to this address to avoid SPF errors.
+  $to = $sender = trim($address);
+}
+else {
+  $error = true;
+}
+
+// Check that referer is local server.
+if (!isset($_SERVER['HTTP_REFERER']) || (parse_url($_SERVER['HTTP_REFERER'], PHP_URL_HOST) != $_SERVER['SERVER_NAME'])) {
+  exit('Direct access not permitted');
+}
+
+// Check that this is a post request.
+if ($_SERVER['REQUEST_METHOD'] != 'POST' || empty($_POST)) {
+  $error = true;
+}
+
+// Check if fake url field is filled in, i.e. spam bot.
+if (!empty($_POST['url'])) {
+  $error = true;
+}
+
+// Check that e-mail address is valid.
+if ((bool) filter_var(trim($_POST['email']), FILTER_VALIDATE_EMAIL)) {
+  $email = trim($_POST['email']);
+}
+else {
+  $error = true;
+}
+
+if (!$error) {
+  // Construct the mail with headers.
+  $name = _contact_clean_str($_POST['name'], ENT_QUOTES, true, true);
+  $prefix = _contact_clean_str($prefix, ENT_NOQUOTES, true, true);
+  $subject = _contact_clean_str($_POST['subject'], ENT_NOQUOTES, true, true);
+  $subject = "[$prefix] $subject";
+  $message = _contact_clean_str($_POST['message'], ENT_NOQUOTES);
+  $lines = explode("\n", $message);
+  array_walk($lines, '_contact_ff_wrap');
+  $message = implode("\n", $lines);
+  $headers = [
+    'From'                      => "$name <$email>",
+    'Sender'                    => $sender,
+    'Return-Path'               => $sender,
+    'MIME-Version'              => '1.0',
+    'Content-Type'              => 'text/plain; charset=UTF-8; format=flowed; delsp=yes',
+    'Content-Transfer-Encoding' => '8Bit',
+    'X-Mailer'                  => 'Hugo - Zen',
+  ];
+  $mime_headers = [];
+  foreach ($headers as $key => $value) {
+    $mime_headers[] = "$key: $value";
+  }
+  $mail_headers = join("\n", $mime_headers);
+
+  // Send the mail, suppressing errors and setting Return-Path with the "-f" option.
+  $success = @mail($to, $subject, $message, $mail_headers, '-f' . $sender);
+}
+
+$status = $success ? 'submitted' : 'error';
+$contact_form_url = strtok($_SERVER['HTTP_REFERER'], '?');
+
+// Redirect back to contact form with status.
+header('Location: ' . $contact_form_url . '?' . $status, TRUE, 302);
+exit;
+
+function _contact_ff_wrap(&$line) {
+  $line = wordwrap($line, 72, " \n");
+}
+
+function _contact_clean_str($str, $quotes, $strip = false, $encode = false) {
+  if ($strip) {
+    $str = strip_tags($str);
+  }
+
+  $str = htmlspecialchars(trim($str), $quotes, 'UTF-8');
+
+  if ($encode && preg_match('/[^\x20-\x7E]/', $str)) {
+    $str = '=?UTF-8?B?' . base64_encode($str) . '?=';
+  }
+
+  return $str;
+}