MDL-59261 theme_boost: compiled css fallback

.stylelintignore

@@ -2,6 +2,7 @@
 theme/bootstrapbase/style/
 theme/clean/style/custom.css
 theme/more/style/custom.css
+theme/boost/style/moodle.css
 node_modules/
 vendor/
 admin/tool/policy/amd/src/jquery-eu-cookie-law-popup.js

Gruntfile.js

@@ -137,6 +137,16 @@ module.exports = function(grunt) {
                 }
            }
         },
+        sass: {
+            dist: {
+                files: {
+                    "theme/boost/style/moodle.css": "theme/boost/scss/preset/default.scss"
+                }
+            },
+            options: {
+                includePaths: ["theme/boost/scss/"]
+            }
+        },
         watch: {
             options: {
                 nospawn: true // We need not to spawn so config can be changed dynamically.
@@ -214,7 +224,8 @@ module.exports = function(grunt) {
           '# Generated by "grunt ignorefiles"',
           'theme/bootstrapbase/style/',
           'theme/clean/style/custom.css',
-          'theme/more/style/custom.css'
+          'theme/more/style/custom.css',
+          'theme/boost/style/moodle.css'
       ].concat(thirdPartyPaths);
       grunt.file.write('.stylelintignore', stylelintIgnores.join('\n'));
     };
@@ -362,6 +373,7 @@ module.exports = function(grunt) {
     grunt.loadNpmTasks('grunt-contrib-uglify');
     grunt.loadNpmTasks('grunt-contrib-less');
     grunt.loadNpmTasks('grunt-contrib-watch');
+    grunt.loadNpmTasks('grunt-sass');
     grunt.loadNpmTasks('grunt-eslint');
     grunt.loadNpmTasks('grunt-stylelint');
 
@@ -374,7 +386,7 @@ module.exports = function(grunt) {
     grunt.registerTask('js', ['amd', 'yui']);
 
     // Register CSS taks.
-    grunt.registerTask('css', ['stylelint:scss', 'stylelint:less', 'less:bootstrapbase', 'stylelint:css']);
+    grunt.registerTask('css', ['stylelint:scss', 'sass', 'stylelint:less', 'less:bootstrapbase', 'stylelint:css']);
 
     // Register the startup task.
     grunt.registerTask('startup', 'Run the correct tasks for the current directory', tasks.startup);

lib/outputlib.php

@@ -662,6 +662,12 @@ class theme_config {
      */
     public $remapiconcache = [];
 
+    /**
+     * The name of the function to call to get precompiled CSS.
+     * @var string
+     */
+    public $precompiledcsscallback = null;
+
     /**
      * Load the config.php file for a particular theme, and return an instance
      * of this class. (That is, this is a factory method.)
@@ -739,7 +745,8 @@ class theme_config {
             'rendererfactory', 'csspostprocess', 'editor_sheets', 'rarrow', 'larrow', 'uarrow', 'darrow',
             'hidefromselector', 'doctype', 'yuicssmodules', 'blockrtlmanipulations',
             'lessfile', 'extralesscallback', 'lessvariablescallback', 'blockrendermethod',
-            'scss', 'extrascsscallback', 'prescsscallback', 'csstreepostprocessor', 'addblockposition', 'iconsystem');
+            'scss', 'extrascsscallback', 'prescsscallback', 'csstreepostprocessor', 'addblockposition',
+            'iconsystem', 'precompiledcsscallback');
 
         foreach ($config as $key=>$value) {
             if (in_array($key, $configurable)) {
@@ -1090,7 +1097,13 @@ class theme_config {
                 } else {
                     if ($type === 'theme' && $identifier === self::SCSS_KEY) {
                         // We need the content from SCSS because this is the SCSS file from the theme.
-                        $csscontent .= $this->get_css_content_from_scss(false);
+                        if ($compiled = $this->get_css_content_from_scss(false)) {
+                            $csscontent .= $compiled;
+                        } else {
+                            // The compiler failed so default back to any precompiled css that might
+                            // exist.
+                            $csscontent .= $this->get_precompiled_css_content();
+                        }
                     } else if ($type === 'theme' && $identifier === $this->lessfile) {
                         // We need the content from LESS because this is the LESS file from the theme.
                         $csscontent .= $this->get_css_content_from_less(false);
@@ -1487,6 +1500,26 @@ class theme_config {
         return $compiled;
     }
 
+    /**
+     * Return the precompiled CSS if the precompiledcsscallback exists.
+     *
+     * @return string Return compiled css.
+     */
+    public function get_precompiled_css_content() {
+        $configs = [$this] + $this->parent_configs;
+        $css = '';
+
+        foreach ($configs as $config) {
+            if (isset($config->precompiledcsscallback)) {
+                $function = $config->precompiledcsscallback;
+                if (function_exists($function)) {
+                    $css .= $function($this);
+                }
+            }
+        }
+        return $css;
+    }
+
     /**
      * Get the icon system to use.
      *

package.json

@@ -12,6 +12,7 @@
     "grunt-contrib-uglify": "1.0.1",
     "grunt-contrib-watch": "1.0.0",
     "grunt-eslint": "20.1.0",
+    "grunt-sass": "2.1.0",
     "grunt-stylelint": "0.6.0",
     "semver": "5.3.0",
     "shifter": "0.5.0",

theme/boost/config.php

@@ -150,6 +150,7 @@ $THEME->enable_dock = false;
 $THEME->csstreepostprocessor = 'theme_boost_css_tree_post_processor';
 $THEME->extrascsscallback = 'theme_boost_get_extra_scss';
 $THEME->prescsscallback = 'theme_boost_get_pre_scss';
+$THEME->precompiledcsscallback = 'theme_boost_get_precompiled_css';
 $THEME->yuicssmodules = array();
 $THEME->rendererfactory = 'theme_overridden_renderer_factory';
 $THEME->requiredblocks = '';

theme/boost/lib.php

@@ -109,6 +109,16 @@ function theme_boost_get_main_scss_content($theme) {
     return $scss;
 }
 
+/**
+ * Get compiled css.
+ *
+ * @return string compiled css
+ */
+function theme_boost_get_precompiled_css() {
+    global $CFG;
+    return file_get_contents($CFG->dirroot . '/theme/boost/style/moodle.css');
+}
+
 /**
  * Get SCSS to prepend.
  *