2 files changed, 55 insertions, 12 deletions

diff --git a/plugins/default_colors/default_colors.css.template b/plugins/default_colors/default_colors.css.template
index 4b269baf..87e22a08 100644
--- a/plugins/default_colors/default_colors.css.template
+++ b/plugins/default_colors/default_colors.css.template
@@ -1,3 +1,3 @@
 :root {
-  %s
+%s
 }
diff --git a/plugins/default_colors/default_colors.php b/plugins/default_colors/default_colors.php
index b898814b..1928cc9f 100644
--- a/plugins/default_colors/default_colors.php
+++ b/plugins/default_colors/default_colors.php
@@ -6,6 +6,7 @@
  * Allow users to easily overrides colors of the default theme.
  */
 
+use Shaarli\Config\ConfigManager;
 use Shaarli\Plugin\PluginManager;
 
 const DEFAULT_COLORS_PLACEHOLDERS = [
@@ -15,7 +16,32 @@ const DEFAULT_COLORS_PLACEHOLDERS = [
 ];
 
 /**
- * When plugin parameters are saved
+ * Display an error if the plugin is active a no color is configured.
+ *
+ * @param $conf ConfigManager instance
+ *
+ * @return array|null The errors array or null of there is none.
+ */
+function default_colors_init($conf)
+{
+    $params = '';
+    foreach (DEFAULT_COLORS_PLACEHOLDERS as $placeholder) {
+        $params .= trim($conf->get('plugins.'. $placeholder, ''));
+    }
+
+    if (empty($params)) {
+        $error = t('Default colors plugin error: '.
+            'This plugin is active and no custom color is configured.');
+        return array($error);
+    }
+}
+
+/**
+ * When plugin parameters are saved, we regenerate the custom CSS file with provided settings.
+ *
+ * @param array $data $_POST array
+ *
+ * @return array Updated $_POST array
  */
 function hook_default_colors_save_plugin_parameters($data)
 {
@@ -27,16 +53,20 @@ function hook_default_colors_save_plugin_parameters($data)
             ? default_colors_format_css_rule($data, $rule) .';'. PHP_EOL
             : '';
     }
-    file_put_contents($file, sprintf($template, $content));
+
+    if (! empty($content)) {
+        file_put_contents($file, sprintf($template, $content));
+    }
+
     return $data;
 }
 
 /**
- * When linklist is displayed, include isso CSS file.
+ * When linklist is displayed, include default_colors CSS file.
  *
  * @param array $data - header data.
  *
- * @return mixed - header data with isso CSS file added.
+ * @return mixed - header data with default_colors CSS file added.
  */
 function hook_default_colors_render_includes($data)
 {
@@ -49,6 +79,26 @@ function hook_default_colors_render_includes($data)
 }
 
 /**
+ * Create a valid CSS rule from parameters settings and plugin parameter.
+ *
+ * @param array  $data      $_POST array
+ * @param string $parameter Plugin parameter name
+ *
+ * @return string CSS rules for the provided parameter and its matching value.
+ */
+function default_colors_format_css_rule($data, $parameter)
+{
+    if (empty($data[$parameter])) {
+        return '';
+    }
+
+    $key = str_replace('DEFAULT_COLORS_', '', $parameter);
+    $key = str_replace('_', '-', strtolower($key)) .'-color';
+    return '  --'. $key .': '. $data[$parameter];
+}
+
+
+/**
  * This function is never called, but contains translation calls for GNU gettext extraction.
  */
 function default_colors_translation()
@@ -59,10 +109,3 @@ function default_colors_translation()
     t('Background color (light grey)');
     t('Dark main color (e.g. visited links)');
 }
-
-function default_colors_format_css_rule($data, $parameter)
-{
-    $key = str_replace('DEFAULT_COLORS_', '', $parameter);
-    $key = str_replace('_', '-', strtolower($key)) .'-color';
-    return '  --'. $key .': '. $data[$parameter];
-}