Creating CSS generation capabilities in the server.

packages/server/src/api/controllers/application.js

@@ -30,6 +30,7 @@ const { BASE_LAYOUTS } = require("../../constants/layouts")
 const { HOME_SCREEN } = require("../../constants/screens")
 const { cloneDeep } = require("lodash/fp")
 const { recurseMustache } = require("../../utilities/mustache")
+const { generateAssetCss } = require("../../utilities/builder/generateCss")
 
 const APP_PREFIX = DocumentTypes.APP + SEPARATOR
 
@@ -119,9 +120,14 @@ exports.fetchAppDefinition = async function(ctx) {
 exports.fetchAppPackage = async function(ctx) {
   const db = new CouchDB(ctx.params.appId)
   const application = await db.get(ctx.params.appId)
-  const layouts = await getLayouts(db)
-  const screens = await getScreens(db)
+  const [layouts, screens] = await Promise.all([getLayouts(db), getScreens(db)])
 
+  for (let layout of layouts) {
+    layout._css = generateAssetCss([layout.props])
+  }
+  for (let screen of screens) {
+    screen._css = generateAssetCss([screen.props])
+  }
   ctx.body = {
     application,
     screens,

packages/server/src/api/controllers/static/index.js

@@ -17,10 +17,16 @@ const setBuilderToken = require("../../../utilities/builder/setBuilderToken")
 const fileProcessor = require("../../../utilities/fileProcessor")
 const { AuthTypes } = require("../../../constants")
 const env = require("../../../environment")
+const { generateAssetCss } = require("../../../utilities/builder/generateCss")
 
 // this was the version before we started versioning the component library
 const COMP_LIB_BASE_APP_VERSION = "0.2.5"
 
+exports.generateCss = async function(ctx) {
+  const structure = ctx.request.body
+  ctx.body = generateAssetCss(structure)
+}
+
 exports.serveBuilder = async function(ctx) {
   let builderPath = resolve(__dirname, "../../../../builder")
   if (ctx.file === "index.html") {

packages/server/src/api/routes/static.js

@@ -24,6 +24,7 @@ if (env.NODE_ENV !== "production") {
 }
 
 router
+  .post("/api/css/generate", authorized(BUILDER), controller.generateCss)
   .post(
     "/api/attachments/process",
     authorized(BUILDER),

packages/server/src/api/routes/tests/generateCss.spec.js

@@ -0,0 +1,46 @@
+const { generateAssetCss, generateCss } = require("../../../utilities/builder/generateCss")
+
+describe("generate_css", () => {
+  it("Check how array styles are output", () => {
+    expect(generateCss({ margin: ["0", "10", "0", "15"] })).toBe("margin: 0 10 0 15;")
+  })
+
+  it("Check handling of an array with empty string values", () => {
+    expect(generateCss({ padding: ["", "", "", ""] })).toBe("")
+  })
+
+  it("Check handling of an empty array", () => {
+    expect(generateCss({ margin: [] })).toBe("")
+  })
+
+  it("Check handling of valid font property", () => {
+    expect(generateCss({ "font-size": "10px" })).toBe("font-size: 10px;")
+  })
+})
+
+
+describe("generate_screen_css", () => {
+  const normalComponent = { _id: "123-456", _component: "@standard-components/header", _children: [], _styles: { normal: { "font-size": "16px" }, hover: {}, active: {}, selected: {} } }
+
+  it("Test generation of normal css styles", () => {
+    expect(generateAssetCss([normalComponent])).toBe(".header-123-456 {\nfont-size: 16px;\n}")
+  })
+
+  const hoverComponent = { _id: "123-456", _component: "@standard-components/header", _children: [], _styles: { normal: {}, hover: {"font-size": "16px"}, active: {}, selected: {} } }
+
+  it("Test generation of hover css styles", () => {
+    expect(generateAssetCss([hoverComponent])).toBe(".header-123-456:hover {\nfont-size: 16px;\n}")
+  })
+
+  const selectedComponent = { _id: "123-456", _component: "@standard-components/header", _children: [], _styles: { normal: {}, hover: {}, active: {}, selected: { "font-size": "16px" } } }
+
+  it("Test generation of selection css styles", () => {
+    expect(generateAssetCss([selectedComponent])).toBe(".header-123-456::selection {\nfont-size: 16px;\n}")
+  }) 
+
+  const emptyComponent = { _id: "123-456", _component: "@standard-components/header", _children: [], _styles: { normal: {}, hover: {}, active: {}, selected: {} } }
+
+  it("Testing handling of empty component styles", () => {
+    expect(generateAssetCss([emptyComponent])).toBe("")
+  }) 
+})

packages/server/src/constants/screens.js

@@ -104,5 +104,31 @@ exports.HOME_SCREEN = {
     route: "/",
     accessLevelId: BUILTIN_LEVEL_IDS.BASIC,
   },
-  name: "d834fea2-1b3e-4320-ab34-f9009f5ecc59",
+  name: "home-screen",
+}
+
+exports.LOGIN_SCREEN = {
+  description: "",
+  url: "",
+  props: {
+    _id: "781e497e-2e7c-11eb-adc1-0242ac120002",
+    _component: "@budibase/standard-components/login",
+    _styles: {
+      normal: {},
+      hover: {},
+      active: {},
+      selected: {},
+    },
+    _code: "",
+    className: "",
+    onLoad: [],
+    type: "div",
+    _children: [],
+    _instanceName: "Login",
+  },
+  routing: {
+    route: "/",
+    accessLevelId: BUILTIN_LEVEL_IDS.PUBLIC,
+  },
+  name: "login-screen",
 }

packages/server/src/utilities/builder/generateCss.js

@@ -0,0 +1,43 @@
+exports.generateAssetCss = component_arr => {
+  let styles = ""
+  for (const { _styles, _id, _children, _component } of component_arr) {
+    let [componentName] = _component.match(/[a-z]*$/)
+    Object.keys(_styles).forEach(selector => {
+      const cssString = exports.generateCss(_styles[selector])
+      if (cssString) {
+        styles += exports.applyClass(_id, componentName, cssString, selector)
+      }
+    })
+    if (_children && _children.length) {
+      styles += exports.generateAssetCss(_children) + "\n"
+    }
+  }
+  return styles.trim()
+}
+
+exports.generateCss = style => {
+  let cssString = Object.entries(style).reduce((str, [key, value]) => {
+    if (typeof value === "string") {
+      if (value) {
+        return (str += `${key}: ${value};\n`)
+      }
+    } else if (Array.isArray(value)) {
+      if (value.length > 0 && !value.every(v => v === "")) {
+        return (str += `${key}: ${value.join(" ")};\n`)
+      }
+    }
+
+    return str
+  }, "")
+
+  return (cssString || "").trim()
+}
+
+exports.applyClass = (id, name = "element", styles, selector) => {
+  if (selector === "normal") {
+    return `.${name}-${id} {\n${styles}\n}`
+  } else {
+    let sel = selector === "selected" ? "::selection" : `:${selector}`
+    return `.${name}-${id}${sel} {\n${styles}\n}`
+  }
+}