diff --git a/src/Controller/ExifSettingsForm.php b/src/Controller/ExifSettingsForm.php
index feaaa33..51c5e7d 100644
--- a/src/Controller/ExifSettingsForm.php
+++ b/src/Controller/ExifSettingsForm.php
@@ -66,13 +66,13 @@ class ExifSettingsForm extends ConfigFormBase implements ContainerInjectionInter
     $form['information1'] = array(
       '#type' => 'item',
       '#title' => 'Informations',
-      '#markup' => t('If you have not create a media/content type for your photographies').', '.t('take a look at <a href="/admin/config/media/exif/helper">the quick start page</a>.'),
+      '#markup' => $this->t('If you have not create a media/content type for your photographies').', '.t('take a look at <a href="/admin/config/media/exif/helper">the quick start page</a>.'),
     );
 
     $form['information2'] = array(
       '#type' => 'item',
       '#title' => '',
-      '#markup' => t('To have a sample of metadata content, take a look at <a href="/admin/config/media/exif/sample">the sample page</a>.'),
+      '#markup' => $this->t('To have a sample of metadata content, take a look at <a href="/admin/config/media/exif/sample">the sample page</a>.'),
     );
 
 
@@ -80,14 +80,14 @@ class ExifSettingsForm extends ConfigFormBase implements ContainerInjectionInter
       '#type' => 'vertical_tabs',
       '#prefix' => '<div class="exif">',
       '#suffix' => '</div>',
-      '#title' => t('Image Metadata Settings'),
-      '#description' => t('If you have not create a media/content type for your photographies').', '.t('take a look at <a href="/admin/config/media/exif/helper">the quick start page</a>.'),
+      '#title' => $this->t('Image Metadata Settings'),
+      '#description' => $this->t('If you have not create a media/content type for your photographies').', '.$this->t('take a look at <a href="/admin/config/media/exif/helper">the quick start page</a>.'),
     );
 
 
     $form['global'] = array(
       '#type' => 'details',
-      '#title' => t('Global Settings'),
+      '#title' => $this->t('Global Settings'),
       '#group' => 'exif',
     );
 
@@ -95,10 +95,10 @@ class ExifSettingsForm extends ConfigFormBase implements ContainerInjectionInter
 
     $form['global']['granularity'] = array(
       '#type' => 'select',
-      '#title' => t('Granularity'),
+      '#title' => $this->t('Granularity'),
       '#options' => array(0 => t('Default'), 1 => ('Day')),
       '#default_value' => $config->get('granularity', 0),
-      '#description' => t('If a timestamp is selected (for example the date the picture was taken), you can specify here how granular the timestamp should be. If you select default it will just take whatever is available in the picture. If you select Day, the Date saved will look something like 13-12-2008. This can be useful if you want to use some kind of grouping on the data.'),
+      '#description' => $this->t('If a timestamp is selected (for example the date the picture was taken), you can specify here how granular the timestamp should be. If you select default it will just take whatever is available in the picture. If you select Day, the Date saved will look something like 13-12-2008. This can be useful if you want to use some kind of grouping on the data.'),
     );
 
     $form['fieldname'] = array(
@@ -108,7 +108,7 @@ class ExifSettingsForm extends ConfigFormBase implements ContainerInjectionInter
 
     $form['node'] = array(
       '#type' => 'details',
-      '#title' => t('Content types'),
+      '#title' => $this->t('Content types'),
       '#group' => 'exif',
     );
     $all_nodetypes = $this->entityTypeManager->getStorage('node_type')->loadMultiple();
@@ -120,7 +120,7 @@ class ExifSettingsForm extends ConfigFormBase implements ContainerInjectionInter
     }
     $form['node']['nodetypes'] = array(
       '#type' => 'checkboxes',
-      '#title' => t('Nodetypes'),
+      '#title' => $this->t('Nodetypes'),
       '#options' => $all_nt,
       '#default_value' => $config->get('nodetypes', array()),
       '#description' => t('Select nodetypes which should be checked for iptc & exif data.'),
@@ -141,7 +141,7 @@ class ExifSettingsForm extends ConfigFormBase implements ContainerInjectionInter
       }
       $form['file']['filetypes'] = array(
         '#type' => 'checkboxes',
-        '#title' => t('Filetypes'),
+        '#title' => $this->t('Filetypes'),
         '#options' => $all_mt,
         '#default_value' => $config->get('filetypes', array()),
         '#description' => t('Select filetypes which should be checked for itpc & exif data.'),
@@ -157,7 +157,7 @@ class ExifSettingsForm extends ConfigFormBase implements ContainerInjectionInter
     if (Drupal::moduleHandler()->moduleExists("media_entity")) {
         $form['media'] = array(
           '#type' => 'details',
-          '#title' => t('Media types'),
+          '#title' => $this->t('Media types'),
           '#group' => 'exif',
         );
 
@@ -169,10 +169,10 @@ class ExifSettingsForm extends ConfigFormBase implements ContainerInjectionInter
         }
         $form['media']['mediatypes'] = array(
           '#type' => 'checkboxes',
-          '#title' => t('Mediatypes'),
+          '#title' => $this->t('Mediatypes'),
           '#options' => $all_mt,
           '#default_value' => $config->get('mediatypes', array()),
-          '#description' => t('Select mediatypes which should be checked for iptc & exif data.'),
+          '#description' => $this->t('Select mediatypes which should be checked for iptc & exif data.'),
         );
     } else {
       $form['media']['mediatypes'] = array(
@@ -184,31 +184,31 @@ class ExifSettingsForm extends ConfigFormBase implements ContainerInjectionInter
 
     $form['global']['update_metadata'] = array(
       '#type' => 'checkbox',
-      '#title' => t('Refresh on node update'),
+      '#title' => $this->t('Refresh on node update'),
       '#default_value' => $config->get('update_metadata', TRUE),
-      '#description' => t('If media/exif enable this option, Exif data is being updated when the node is being updated.'),
+      '#description' => $this->t('If media/exif enable this option, Exif data is being updated when the node is being updated.'),
     );
 
     $form['global']['extraction_solution'] = array(
       '#type' => 'select',
-      '#title' => t('which extraction solution to use on node update'),
+      '#title' => $this->t('which extraction solution to use on node update'),
       '#options' => ExifFactory::getExtractionSolutions(),
       '#default_value' => $config->get('extraction_solution', "php_extensions"),
-      '#description' => t('If media/exif enable this option, Exif data is being updated when the node is being updated.'),
+      '#description' => $this->t('If media/exif enable this option, Exif data is being updated when the node is being updated.'),
     );
 
     $form['global']['exiftool_location'] = array(
       '#type' => 'textfield',
-      '#title' => t('location of exiftool binary'),
+      '#title' => $this->t('location of exiftool binary'),
       '#default_value' => $config->get('exiftool_location', "exiftool"),
-      '#description' => t('where is the exiftool binaries (only needed if extraction solution chosen is exiftool)'),
+      '#description' => $this->t('where is the exiftool binaries (only needed if extraction solution chosen is exiftool)'),
     );
 
     $form['global']['write_empty_values'] = array(
       '#type' => 'checkbox',
-      '#title' => t('Write empty image data?'),
+      '#title' => $this->t('Write empty image data?'),
       '#default_value' => $config->get('write_empty_values', TRUE),
-      '#description' => t("If checked all values will be written. So for example if you want to read the creation date from EXIF, but it's not available, it will just write an empty string. If unchecked, empty strings will not be written. This might be the desired behavior, if you have a default value for the CCK field."),
+      '#description' => $this->t("If checked all values will be written. So for example if you want to read the creation date from EXIF, but it's not available, it will just write an empty string. If unchecked, empty strings will not be written. This might be the desired behavior, if you have a default value for the CCK field."),
     );
 
     $all_vocabularies = Vocabulary::loadMultiple();
@@ -220,10 +220,10 @@ class ExifSettingsForm extends ConfigFormBase implements ContainerInjectionInter
     }
     $form['global']['vocabulary'] = array(
       '#type' => 'select',
-      '#title' => t('Default Vocabulary'),
+      '#title' => $this->t('Default Vocabulary'),
       '#options' => $all_vocs,
       '#default_value' => $config->get('vocabulary', array()),
-      '#description' => t('Select vocabulary which should be used for iptc & exif data.').t('If you think no vocabulary is usable for the purpose').', '.t('take a look at <a href="/admin/config/media/exif/helper">the quick start page</a>.'),
+      '#description' => $this->t('Select vocabulary which should be used for iptc & exif data.').t('If you think no vocabulary is usable for the purpose').', '.$this->t('take a look at <a href="/admin/config/media/exif/helper">the quick start page</a>.'),
     );
     //TODO : Check if the media module is install to add automatically the image type active and add active default exif field (title,model,keywords).
     return parent::buildForm($form, $form_state);
diff --git a/src/ExifHelp.php b/src/ExifHelp.php
index 5e4ad7a..895586c 100644
--- a/src/ExifHelp.php
+++ b/src/ExifHelp.php
@@ -28,13 +28,13 @@ class ExifHelp {
     $permissionUrl = Url::fromRoute('user.admin_permissions')->toString();
 
     $output = '';
-    $output .= '<h2>' . t('About') . '</h2>';
-    $output .= '<p>' . t('The Exif module allows you :');
-    $output .= '<ul><li>' . t('extract metadata from an image') . '</li>';
-    $output .= '<li>' . t('to classify your images by settings terms in taxonamy vocabulary') . '</li></ul>';
-    $output .= t('To classify images, you define <em>vocabularies</em> that contain related <em>terms</em>, and then assign the vocabularies to content types. For more information, see the online handbook entry for the <a href="http://drupal.org/handbook/modules/taxonomy/">Taxonomy module</a>.');
+    $output .= '<h2>' . $this->t('About') . '</h2>';
+    $output .= '<p>' . $this->t('The Exif module allows you :');
+    $output .= '<ul><li>' . $this->t('extract metadata from an image') . '</li>';
+    $output .= '<li>' . $this->t('to classify your images by settings terms in taxonamy vocabulary') . '</li></ul>';
+    $output .= $this->t('To classify images, you define <em>vocabularies</em> that contain related <em>terms</em>, and then assign the vocabularies to content types. For more information, see the online handbook entry for the <a href="http://drupal.org/handbook/modules/taxonomy/">Taxonomy module</a>.');
     $output .= '</p>';
-    $output .= '<h2>' . t('Uses') . '</h2>';
+    $output .= '<h2>' . $this->t('Uses') . '</h2>';
     $output .= '<p>';
     $output .= ' Several step are needed to get metadata information and be able to classify image and associated content';
     $output .= '<ul>';
@@ -43,28 +43,28 @@ class ExifHelp {
     $output .= '<li><a href="#create-fields">create content types and fields </a></li>';
     $output .= '</ul>';
     $output .= '</p>';
-    $output .= '<h4 id="create-vocabulary">' . t('Creating vocabularies') . '</h4>';
+    $output .= '<h4 id="create-vocabulary">' . $this->t('Creating vocabularies') . '</h4>';
     $output .= '<p>';
-    $output .= t('Users with sufficient <a href="'.$permissionUrl.'">permissions</a> can create <em>vocabularies</em> through the <a href="'.$taxonomyUrl.'">Taxonomy page</a>. The page listing the terms provides a drag-and-drop interface for controlling the order of the terms and sub-terms within a vocabulary, in a hierarchical fashion.');
-    $output .= t('This module will automatically create in the chosen vocabulary (by default "Photographies\' metadata"), the following structure:');
+    $output .= $this->t('Users with sufficient <a href="'.$permissionUrl.'">permissions</a> can create <em>vocabularies</em> through the <a href="'.$taxonomyUrl.'">Taxonomy page</a>. The page listing the terms provides a drag-and-drop interface for controlling the order of the terms and sub-terms within a vocabulary, in a hierarchical fashion.');
+    $output .= $this->t('This module will automatically create in the chosen vocabulary (by default "Photographies\' metadata"), the following structure:');
     $output .= '</p>';
-    $output .= '<ul><li>' . t('<em>vocabulary</em>: Photographies\'metadata') . '</li>';
-    $output .= '<ul><li>' . t('<em>term</em>: iptc') . '</li>';
-    $output .= '<ul><li>' . t('<em>sub-term</em>: keywords') . '</li>';
-    $output .= '<ul><li>' . t('<em>ursub-term</em>: Paris') . '</li>';
-    $output .= '<li>' . t('<em>sub-term</em>: Friends') . '</li>';
+    $output .= '<ul><li>' . $this->t('<em>vocabulary</em>: Photographies\'metadata') . '</li>';
+    $output .= '<ul><li>' . $this->t('<em>term</em>: iptc') . '</li>';
+    $output .= '<ul><li>' . $this->t('<em>sub-term</em>: keywords') . '</li>';
+    $output .= '<ul><li>' . $this->t('<em>ursub-term</em>: Paris') . '</li>';
+    $output .= '<li>' . $this->t('<em>sub-term</em>: Friends') . '</li>';
     $output .= '</ul></ul>';
-    $output .= '<ul><li>' . t('<em>sub-term</em>: caption') . '</li>';
-    $output .= '<ul><li>' . t('<em>sub-term</em>: Le louvre') . '</li>';
+    $output .= '<ul><li>' . $this->t('<em>sub-term</em>: caption') . '</li>';
+    $output .= '<ul><li>' . $this->t('<em>sub-term</em>: Le louvre') . '</li>';
     $output .= '</ul></ul></ul>';
-    $output .= '<ul><li>' . t('<em>term</em>: exif') . '</li>';
-    $output .= '<ul><li>' . t('<em>sub-term</em>: model') . '</li>';
-    $output .= '<ul><li>' . t('<em>sub-term</em>: KINON DE800') . '</li>';
+    $output .= '<ul><li>' . $this->t('<em>term</em>: exif') . '</li>';
+    $output .= '<ul><li>' . $this->t('<em>sub-term</em>: model') . '</li>';
+    $output .= '<ul><li>' . $this->t('<em>sub-term</em>: KINON DE800') . '</li>';
     $output .= '</ul></ul>';
-    $output .= '<ul><li>' . t('<em>sub-term</em>: isospeedratings') . '</li>';
-    $output .= '<ul><li>' . t('<em>sub-term</em>: 200') . '</li>';
+    $output .= '<ul><li>' . $this->t('<em>sub-term</em>: isospeedratings') . '</li>';
+    $output .= '<ul><li>' . $this->t('<em>sub-term</em>: 200') . '</li>';
     $output .= '</ul></ul></ul></ul>';
-    $output .= '<h4 id="choose-extraction-solution">' . t('Choose the solution to extract metadata') . '</h4>';
+    $output .= '<h4 id="choose-extraction-solution">' . $this->t('Choose the solution to extract metadata') . '</h4>';
     $output .= '<p>';
     $output .= ' Several solution are now implemented to extract metadata from image :';
     $output .= '<ul>';
@@ -73,21 +73,21 @@ class ExifHelp {
     $output .= '<!--<li><span>the gearman exiftool </span>is the \'scalable\' solution. Advantages is exiftool better metadata support and scalability.Drawbacks is the complexity of installation and some non supported platforms.-->';
     $output .= '</ul>';
     $output .= '</p>';
-    $output .= '<h4 id="create-fields">' . t('Creating fields to store metadata information') . '</h4>';
+    $output .= '<h4 id="create-fields">' . $this->t('Creating fields to store metadata information') . '</h4>';
     $output .= '<p>';
-    $output .= t('To get metadata information of an image, you have to choose on which node type the extraction should be made.');
-    $output .= t('You also have to create fields with specific names using the Field UI.'). '</p>';
-    $output .= t('The type of the field can be :');
-    $output .= '<ul><li>' . t('<em>text field</em>: extract information and put it in the text field.') . '</li>';
-    $output .= '<li>' . t('<em>date field</em>: extract information and put it in the date field.') . '</li>';
-    $output .= '<li>' . t('<em>term reference field</em>: extract information, create terms and sub-terms if needed and put it in the field.') . '</li>';
+    $output .= $this->t('To get metadata information of an image, you have to choose on which node type the extraction should be made.');
+    $output .= $this->t('You also have to create fields with specific names using the Field UI.'). '</p>';
+    $output .= $this->t('The type of the field can be :');
+    $output .= '<ul><li>' . $this->t('<em>text field</em>: extract information and put it in the text field.') . '</li>';
+    $output .= '<li>' . $this->t('<em>date field</em>: extract information and put it in the date field.') . '</li>';
+    $output .= '<li>' . $this->t('<em>term reference field</em>: extract information, create terms and sub-terms if needed and put it in the field.') . '</li>';
     $output .= '</ul>';
-    $output .= t('Please, if you want to use term reference field, ensure :');
-    $output .= '<ul><li>' . t('you choose the autocompletion widget and') . '</li>';
-    $output .= '<li>' . t('the chosen Vocabulary exists')." (".t('see previous section').' <a href="#create-vocabulary">'.t('Creating vocabularies').'</a>)' . '</li>';
+    $output .= $this->t('Please, if you want to use term reference field, ensure :');
+    $output .= '<ul><li>' . $this->t('you choose the autocompletion widget and') . '</li>';
+    $output .= '<li>' . $this->t('the chosen Vocabulary exists')." (".$this->t('see previous section').' <a href="#create-vocabulary">'.$this->t('Creating vocabularies').'</a>)' . '</li>';
     $output .= '</ul>';
-    $output .= '<b>'.t('Important !').'</b> : '.t('Note for iptc and exif fields that have several values (like field iptc "keywords" as an example), ');
-    $output .= t('if you want to get all the values, do not forget to configure the field to use unlimited number of values (by default, set to 1).');
+    $output .= '<b>'.$this->t('Important !').'</b> : '.$this->t('Note for iptc and exif fields that have several values (like field iptc "keywords" as an example), ');
+    $output .= $this->t('if you want to get all the values, do not forget to configure the field to use unlimited number of values (by default, set to 1).');
     $output .= '</p>';
     $rows = array();
     $help = '';
@@ -128,7 +128,7 @@ class ExifHelp {
       }
       $output .= '<div class="sample-image">';
       $output .= '<h3 class="sample-image">';
-      $output .= t('Example of field name and the metadata extracted');
+      $output .= $this->t('Example of field name and the metadata extracted');
       $output .= '</h3>';
       $output .= '<img class="sample-image" src="' . $imageUrl . '"/>';
       $output .= '</div>';
diff --git a/src/Plugin/Field/FieldWidget/ExifFieldWidgetBase.php b/src/Plugin/Field/FieldWidget/ExifFieldWidgetBase.php
index a38254e..36bfe09 100644
--- a/src/Plugin/Field/FieldWidget/ExifFieldWidgetBase.php
+++ b/src/Plugin/Field/FieldWidget/ExifFieldWidgetBase.php
@@ -37,8 +37,8 @@ abstract class ExifFieldWidgetBase extends ExifWidgetBase {
     );
     $element['exif_field_separator'] = array(
       '#type' => 'textfield',
-      '#title' => t('exif field separator'),
-      '#description' => t('separator used to split values (if field definition support several values). let it empty if you do not want to split values.'),
+      '#title' => $this->t('exif field separator'),
+      '#description' => $this->t('separator used to split values (if field definition support several values). let it empty if you do not want to split values.'),
       '#default_value' => $default_exif_separator_value,
       '#element_validate' => array(
         array(
@@ -58,21 +58,21 @@ abstract class ExifFieldWidgetBase extends ExifWidgetBase {
 
     $exif_field_separator = $this->getSetting('exif_field_separator');
     if (isset($exif_field_separator) && strlen($exif_field_separator) == 1) {
-      $exif_field_msg = t("exif value will be split using character separator '@separator'", array('@separator' => $exif_field_separator));
+      $exif_field_msg = $this->t("exif value will be split using character separator '@separator'", array('@separator' => $exif_field_separator));
     }
     else {
-      $exif_field_msg = t('exif value will be extracted as one value');
+      $exif_field_msg = $this->t('exif value will be extracted as one value');
     }
     array_unshift($summary, $exif_field_msg);
 
     $exif_field = $this->getSetting('exif_field');
     if (isset($exif_field) && $exif_field != 'naming_convention') {
-      $exif_field_msg = t("exif data will be extracted from image metadata field '@metadata'", array('@metadata' => $exif_field));
+      $exif_field_msg = $this->t("exif data will be extracted from image metadata field '@metadata'", array('@metadata' => $exif_field));
     }
     else {
       $fieldname = $this->fieldDefinition->getName();
       $exif_field = str_replace("field_", "", $fieldname);
-      $exif_field_msg = t("Using naming convention. so the exif data will be extracted from image metadata field '@metadata'", array('@metadata' => $exif_field));
+      $exif_field_msg = $this->t("Using naming convention. so the exif data will be extracted from image metadata field '@metadata'", array('@metadata' => $exif_field));
     }
     array_unshift($summary, $exif_field_msg);
 
@@ -93,7 +93,7 @@ abstract class ExifFieldWidgetBase extends ExifWidgetBase {
   public static function validateExifField($element, FormStateInterface $form_state, $form) {
     $elementSettings = $form_state->getValue($element['#parents']);
     if (!$elementSettings) {
-      $message = t('you must choose at least one method to retrieve image metadata.');
+      $message = $this->t('you must choose at least one method to retrieve image metadata.');
       $form_state->setErrorByName('exif_field', $message);
     }
   }
@@ -101,7 +101,7 @@ abstract class ExifFieldWidgetBase extends ExifWidgetBase {
   public static function validateExifFieldSeparator($element, &$form_state) {
     $elementSettings = $form_state->getValue($element['#parents']);
     if (!empty($elementSettings) && strlen($elementSettings) > 1) {
-      $message = t('the separator is only one character long.');
+      $message = $this->t('the separator is only one character long.');
       $form_state->setErrorByName('exif_field_separator', $message);
     }
   }
diff --git a/src/Plugin/Field/FieldWidget/ExifWidgetBase.php b/src/Plugin/Field/FieldWidget/ExifWidgetBase.php
index 107a6b3..da59663 100644
--- a/src/Plugin/Field/FieldWidget/ExifWidgetBase.php
+++ b/src/Plugin/Field/FieldWidget/ExifWidgetBase.php
@@ -32,8 +32,8 @@ abstract class ExifWidgetBase extends WidgetBase {
       $default_image_value = $this->retrieveImageFieldDefaultValue($element, $image_fields);
       $element['image_field'] = array(
         '#type' => 'radios',
-        '#title' => t('image field to use to retrieve data'),
-        '#description' => t('determine the image used to look for exif and iptc metadata'),
+        '#title' => $this->t('image field to use to retrieve data'),
+        '#description' => $this->t('determine the image used to look for exif and iptc metadata'),
         '#options' => $image_fields,
         '#default_value' => $default_image_value,
         '#element_validate' => array(
@@ -74,10 +74,10 @@ abstract class ExifWidgetBase extends WidgetBase {
           $label = $image_field;
         }
       }
-      $image_field_msg = t("exif will be extracted from image field @image", array('@image' => $label));
+      $image_field_msg = $this->t("exif will be extracted from image field @image", array('@image' => $label));
     }
     else {
-      $image_field_msg = t('No image chosen. field will stay empty.');
+      $image_field_msg = $this->t('No image chosen. field will stay empty.');
     }
     array_unshift($summary, $image_field_msg);
 
@@ -108,9 +108,9 @@ abstract class ExifWidgetBase extends WidgetBase {
       $field_storage = $field_storage_definitions[$element['#field_name']];
       if ($field_storage) {
         $args = array('%field' => $field_storage->getName());
-        $message = t('Field %field must be link to an image field.', $args);
+        $message = $this->t('Field %field must be link to an image field.', $args);
       } else {
-        $message = t('Field must be link to an image field.');
+        $message = $this->t('Field must be link to an image field.');
       }
       $form_state->setErrorByName('image_field', $message);
     }
diff --git a/src/Tests/exif_functionaltests.php b/src/Tests/exif_functionaltests.php
index 200e17e..226015d 100755
--- a/src/Tests/exif_functionaltests.php
+++ b/src/Tests/exif_functionaltests.php
@@ -191,14 +191,14 @@ abstract class ExifFunctionalTestCase extends DrupalWebTestCase {
     $this->assertNotNull($node, "node created", 'Exif');
     $this->verbose('Node created: ' . var_export($node, TRUE));
     $this->drupalGet("node/{$node->nid}/edit");
-    $this->assertResponse(200, t('User is allowed to edit the content.'), 'Exif');
+    $this->assertResponse(200, $this->t('User is allowed to edit the content.'), 'Exif');
     $this->assertText(t("@title", array('@title' => $settings['title'])), "Found title in edit form", 'Exif');
-    $this->drupalPost(NULL, array(), t('Save'));
-    $this->assertResponse(200, t('trying to submit node.'), 'Exif');
-    $this->assertNoText("The content on this page has either been modified by another user, or you have already submitted modifications using this form. As a result, your changes cannot be saved.", t('form has been correctly submitted'), 'Exif');
+    $this->drupalPost(NULL, array(), $this->t('Save'));
+    $this->assertResponse(200, $this->t('trying to submit node.'), 'Exif');
+    $this->assertNoText("The content on this page has either been modified by another user, or you have already submitted modifications using this form. As a result, your changes cannot be saved.", $this->t('form has been correctly submitted'), 'Exif');
     $noedit = array();
     $this->drupalGet("node/{$node->nid}");
-    $this->assertResponse(200, t('photography node edition is complete.'), 'Exif');
+    $this->assertResponse(200, $this->t('photography node edition is complete.'), 'Exif');
   }
 
   public function testCreatePhotoNodeWithImage() {
@@ -215,7 +215,7 @@ abstract class ExifFunctionalTestCase extends DrupalWebTestCase {
     //assert hidden field are present
     $this->assertField("field_iptc_keywords[und][0][tid]", "hidden field keywords is present", "Exif");
     $this->assertField("field_exif_model[und][0][tid]", "hidden field model is present", "Exif");
-    $this->assertResponse(200, t('User is allowed to edit the content.'), 'Exif');
+    $this->assertResponse(200, $this->t('User is allowed to edit the content.'), 'Exif');
     $this->assertText(t("@title", array('@title' => $settings['title'])), "Found title in edit form", 'Exif');
     $img_path = drupal_get_path('module', 'exif') . "/sample.jpg";
     $this->assertTrue(file_exists($img_path), "file {$img_path} exists.", "Exif");
@@ -223,17 +223,17 @@ abstract class ExifFunctionalTestCase extends DrupalWebTestCase {
       'files[field_image_und_0]' => $img_path
     );
     $this->drupalPostAJAX(NULL, $file_upload, 'field_image_und_0_upload_button');
-    $this->assertResponse(200, t('photo is uploaded.'), 'Exif');
+    $this->assertResponse(200, $this->t('photo is uploaded.'), 'Exif');
     $this->drupalGet("node/{$node->nid}/edit");
     $fid = $this->getLastFileId();
     $file_uploaded_attach = array(
       'field_image[und][0][fid]' => $fid
     );
     $this->drupalPost(NULL, $file_uploaded_attach, t('Save'));
-    $this->assertResponse(200, t('trying to submit node.'), 'Exif');
+    $this->assertResponse(200, $this->t('trying to submit node.'), 'Exif');
     $this->assertNoText("The content on this page has either been modified by another user, or you have already submitted modifications using this form. As a result, your changes cannot be saved.", t('form has been correctly submitted'), 'Exif');
     $this->drupalGet("node/{$node->nid}");
-    $this->assertResponse(200, t('photography node edition is complete.'), 'Exif');
+    $this->assertResponse(200, $this->t('photography node edition is complete.'), 'Exif');
     //check for label
     $this->assertText("model");
     $this->assertText("keywords");
diff --git a/src/Tests/exif_functionaltests_with_defaults.test b/src/Tests/exif_functionaltests_with_defaults.test
index d745e0d..bc0e0e4 100755
--- a/src/Tests/exif_functionaltests_with_defaults.test
+++ b/src/Tests/exif_functionaltests_with_defaults.test
@@ -1,4 +1,5 @@
 <?php
+
 include_once drupal_get_path('module', 'exif') . '/exif_functionaltests.php';
 
 class TestsWithDefaultEnvironmentTestCase extends ExifFunctionalTestCase {
diff --git a/src/Tests/exif_functionaltests_with_locale.test b/src/Tests/exif_functionaltests_with_locale.test
index e7993da..b2ebaee 100755
--- a/src/Tests/exif_functionaltests_with_locale.test
+++ b/src/Tests/exif_functionaltests_with_locale.test
@@ -1,4 +1,5 @@
 <?php
+
 include_once drupal_get_path('module', 'exif') . '/exif_functionaltests.php';
 
 class TestsWithLocaleModuleActivatedTestCase extends ExifFunctionalTestCase {