Allows disabling CSS for a plugin

If a plugin does not require styles, a css file will not be produced by the optimizer. Previously this wasn't an issue as all plugins were including duplicated styles (kibana/15816).

Signed-off-by: Tyler Smalley <tyler.smalley@elastic.co>

src/core_plugins/state_session_storage_redirect/index.js

@@ -7,6 +7,7 @@ export default function (kibana) {
         id: 'stateSessionStorageRedirect',
         main: 'plugins/state_session_storage_redirect',
         hidden: true,
+        hasCSS: false,
       }
     }
   });

src/ui/ui_apps/__tests__/ui_app.js

@@ -15,6 +15,7 @@ function createStubUiAppSpec(extraParams) {
     linkToLastSubUrl: true,
     hidden: false,
     listed: false,
+    hasCSS: false,
     templateName: 'ui_app_test',
     uses: [
       'visTypes',
@@ -86,6 +87,10 @@ describe('UiApp', () => {
         expect(app.getNavLink()).to.be.a(UiNavLink);
       });
 
+      it('has CSS', () => {
+        expect(app.getHasCSS()).to.be(true);
+      });
+
       it('has no injected vars', () => {
         expect(app.getInjectedVars()).to.be(undefined);
       });
@@ -139,6 +144,10 @@ describe('UiApp', () => {
         expect(app.getNavLink()).to.be(undefined);
       });
 
+      it('has no CSS', () => {
+        expect(app.getHasCSS()).to.be(false);
+      });
+
       it('has injected vars', () => {
         expect(app.getInjectedVars()).to.eql({ foo: 'bar' });
       });

src/ui/ui_apps/ui_app.js

@@ -15,6 +15,7 @@ export class UiApp {
       listed,
       templateName = 'ui_app',
       injectVars,
+      hasCSS = true,
       url = `/app/${id}`,
       uses = []
     } = spec;
@@ -35,6 +36,7 @@ export class UiApp {
     this._templateName = templateName;
     this._url = url;
     this._injectedVarsProvider = injectVars;
+    this._hasCSS = hasCSS;
     this._pluginId = pluginId;
     this._kbnServer = kbnServer;
 
@@ -98,6 +100,10 @@ export class UiApp {
     }
   }
 
+  getHasCSS() {
+    return this._hasCSS;
+  }
+
   getInjectedVars() {
     const provider = this._injectedVarsProvider;
     const plugin = this._getPlugin();

src/ui/ui_exports/ui_export_types/ui_apps.js

@@ -17,6 +17,7 @@ function applySpecDefaults(spec, type, pluginSpec) {
     listed = !hidden,
     templateName = 'ui_app',
     injectVars = noop,
+    hasCSS = true,
     url = `/app/${id}`,
     uses = [],
   } = spec;
@@ -34,6 +35,7 @@ function applySpecDefaults(spec, type, pluginSpec) {
     listed,
     templateName,
     injectVars,
+    hasCSS,
     url,
     uses: uniq([
       ...uses,

src/ui/ui_render/views/ui_app.jade

@@ -121,11 +121,14 @@ block content
       }
       var files = [
         bundleFile('commons.style.css'),
-        bundleFile('#{app.getId()}.style.css'),
         bundleFile('commons.bundle.js'),
         bundleFile('#{app.getId()}.bundle.js')
       ];
 
+      if ('#{app.getHasCSS()}' == 'true') {
+        files.push(bundleFile('#{app.getId()}.style.css'));
+      }
+
       (function next() {
         var file = files.shift();
         if (!file) return;