Added GDPR docs

docs/helpful-guides/gdpr.md

@@ -0,0 +1,47 @@
+# GDPR and Yii2-usuario
+
+EU regulation
+The General Data Protection Regulation (GDPR) (EU) 2016/679 is a regulation in EU law on data protection and privacy for all individuals within the European Union and the European Economic Area. It also addresses the export of personal data outside the EU and EEA. The GDPR aims primarily to give control to citizens and residents over their personal data and to simplify the regulatory environment for international business by unifying the regulation within the EU
+
+## Enable GDPR
+
+To enable support in yii2-usuario set `enableGDPRcompliance` to `true` and set
+  `GDPRprivacyPolicyUrl` with an url pointing to your privacy policy.
+
+### At this moment a few measures apply to your app:
+
+#### Data processing consent:
+
+All users must give consent of data processing to register.
+Also consent will be stored in db with the user data.
+
+#### Data portability
+
+Gdpr says:
+> The data subject shall have the right to receive the personal data concerning him or her, which he
+> or she has provided to a controller, in a structured, commonly used and machine-readable format\[...]
+
+Users now have a privacy page in their account settings where they can export his/her personal data
+in a csv file.
+If you collect additional personal information you can to export by adding to
+`GDPRexportProperties`.
+> Export use `ArrayHelper::getValue()` to extract information, so you can use links to relations.
+
+
+#### Right to be forgotten
+
+GDPR says: [Article 17](https://gdpr.algolia.com/gdpr-article-17)
+> The data subject shall have the right to obtain from the controller the erasure of personal data concerning him or her without undue delay and the controller shall have the obligation to erase personal data without undue delay\[...]
+
+In privacy page, users will find a button to delete their personal information.
+The behavior differs depending module configuration.
+
+If  `$allowAccountDelete` is set to `true` the account will be fully deleted when clicking *Delete* button,
+while when if that setting is set to `false` the module will remove social network connections and
+replace the personal data with a custom alias defined in `$GDPRanonymPrefix`.
+
+The account will be blocked and marked as `gdpr_deleted`.
+
+That way you can keep your site operation as normal.
+
+> If you need to delete additional information use the `GdprEvent::EVENT_BEFORE_DELETE`.

docs/installation/configuration-options.md

@@ -7,10 +7,41 @@ The module comes with a set of attributes to configure. The following is the lis
 
 Setting this attribute will allow users to configure their login process with two-factor authentication. 
 
-### twoFactorAuthenticationCycles (type: `integer`, default: `1`)
+#### twoFactorAuthenticationCycles (type: `integer`, default: `1`)
 
 By default, Google Authenticator App for two-factor authentication cycles in periods of 30 seconds. In order to allow 
-a bigger period so to avoid out of sync issues. 
+a bigger period so to avoid out of sync issues.
+
+#### enableGDPRcompliance (type: `boolean`, default: `false`)
+
+Setting this attribute enables a serie of measures to comply with EU GDPR regulation, like data consent, right to be forgotten and data portability.
+
+#### GDPRprivacyPolicyUrl (type: `array`, default: null)
+The link to privacy policy. This will be used on registration form as "read our pivacy policy". It must follow the same format as `yii\helpers\Url::to`
+
+#### GDPRexportProperties (type: `array`)
+
+An array with the name of the user identity properties to be included when user request download of his data.
+Names can include relations like `profile.name`.
+
+Defaults to:
+```php
+      [
+        'email',
+        'username',
+        'profile.public_email',
+        'profile.name',
+        'profile.gravatar_email',
+        'profile.location',
+        'profile.website',
+        'profile.bio'
+      ]
+```
+
+
+#### GDPRanonymPrefix (type: `string`, default: `GDPR`)
+Prefix to be used as a replacement when user requeste deletion of his data
+
 
 #### enableRegistration (type: `boolean`, default: `true`)