WIP - Plugin to override default template colors

  * Adds a new core plugin to override default template colors
  * Adds a new hook when plugin settings are saved
(`save_plugin_parameters`)
  * Use CSS native variables for main colors instead of SASS variables
  * Disable SASS sort order rules due to a bug in the plugin

Fixes #1312

3 files changed, 76 insertions, 0 deletions

diff --git a/plugins/default_colors/default_colors.css.template b/plugins/default_colors/default_colors.css.template
new file mode 100644
index 00000000..4b269baf
--- /dev/null
+++ b/plugins/default_colors/default_colors.css.template
@@ -0,0 +1,3 @@
+:root {
+  %s
+}
diff --git a/plugins/default_colors/default_colors.meta b/plugins/default_colors/default_colors.meta
new file mode 100644
index 00000000..108962c6
--- /dev/null
+++ b/plugins/default_colors/default_colors.meta
@@ -0,0 +1,5 @@
+description="Override default theme colors. Use any CSS valid color."
+parameters="DEFAULT_COLORS_MAIN;DEFAULT_COLORS_BACKGROUND;DEFAULT_COLORS_DARK_MAIN"
+parameter.DEFAULT_COLORS_MAIN="Main color (navbar green)"
+parameter.DEFAULT_COLORS_BACKGROUND="Background color (light grey)"
+parameter.DEFAULT_COLORS_DARK_MAIN="Dark main color (e.g. visited links)"
diff --git a/plugins/default_colors/default_colors.php b/plugins/default_colors/default_colors.php
new file mode 100644
index 00000000..b898814b
--- /dev/null
+++ b/plugins/default_colors/default_colors.php
@@ -0,0 +1,68 @@
+<?php
+
+/**
+ * Plugin default_colors.
+ *
+ * Allow users to easily overrides colors of the default theme.
+ */
+
+use Shaarli\Plugin\PluginManager;
+
+const DEFAULT_COLORS_PLACEHOLDERS = [
+    'DEFAULT_COLORS_MAIN',
+    'DEFAULT_COLORS_BACKGROUND',
+    'DEFAULT_COLORS_DARK_MAIN',
+];
+
+/**
+ * When plugin parameters are saved
+ */
+function hook_default_colors_save_plugin_parameters($data)
+{
+    $file = PluginManager::$PLUGINS_PATH . '/default_colors/default_colors.css';
+    $template = file_get_contents(PluginManager::$PLUGINS_PATH . '/default_colors/default_colors.css.template');
+    $content = '';
+    foreach (DEFAULT_COLORS_PLACEHOLDERS as $rule) {
+        $content .= ! empty($data[$rule])
+            ? default_colors_format_css_rule($data, $rule) .';'. PHP_EOL
+            : '';
+    }
+    file_put_contents($file, sprintf($template, $content));
+    return $data;
+}
+
+/**
+ * When linklist is displayed, include isso CSS file.
+ *
+ * @param array $data - header data.
+ *
+ * @return mixed - header data with isso CSS file added.
+ */
+function hook_default_colors_render_includes($data)
+{
+    $file = PluginManager::$PLUGINS_PATH . '/default_colors/default_colors.css';
+    if (file_exists($file )) {
+        $data['css_files'][] = $file ;
+    }
+
+    return $data;
+}
+
+/**
+ * This function is never called, but contains translation calls for GNU gettext extraction.
+ */
+function default_colors_translation()
+{
+    // meta
+    t('Override default theme colors. Use any CSS valid color.');
+    t('Main color (navbar green)');
+    t('Background color (light grey)');
+    t('Dark main color (e.g. visited links)');
+}
+
+function default_colors_format_css_rule($data, $parameter)
+{
+    $key = str_replace('DEFAULT_COLORS_', '', $parameter);
+    $key = str_replace('_', '-', strtolower($key)) .'-color';
+    return '  --'. $key .': '. $data[$parameter];
+}