feat: switch engine-twig to use twing rather than node-twig

packages/engine-twig/lib/engine_twig.js

@@ -22,44 +22,126 @@
 
 const fs = require('fs-extra');
 const path = require('path');
-const process = require('process');
-const Twig = require('node-twig');
-const twig = Twig.renderFile;
+const {
+  TwingEnvironment,
+  TwingLoaderFilesystem,
+  TwingLoaderChain,
+  TwingSource,
+} = require('twing');
+
+class TwingLoaderPatternLab {
+  patterns = new Map();
+
+  constuctor() {}
+
+  registerPartial(pattern) {
+    if (pattern.patternPartial) {
+      this.patterns.set(pattern.patternPartial, pattern);
+    }
+  }
+
+  /**
+   * Returns the source context for a given template logical name.
+   *
+   * @param {string} name The template logical name
+   * @param {TwingSource} from The source that initiated the template loading
+   *
+   * @returns {Promise<TwingSource>}
+   *
+   * @throws TwingErrorLoader When name is not found
+   */
+  getSourceContext(name, from) {
+    var pattern = this.patterns.get(name);
+    return Promise.resolve(
+      new TwingSource(pattern.extendedTemplate, name, pattern.relPath)
+    );
+  }
+
+  /**
+   * Gets the cache key to use for the cache for a given template name.
+   *
+   * @param {string} name The name of the template to load
+   * @param {TwingSource} from The source that initiated the template loading
+   *
+   * @returns {Promise<string>} The cache key
+   *
+   * @throws TwingErrorLoader When name is not found
+   */
+  getCacheKey(name, from) {
+    return Promise.resolve(name);
+  }
+
+  /**
+   * Returns true if the template is still fresh.
+   *l
+   * @param {string} name The template name
+   * @param {number} time Timestamp of the last modification time of the cached template
+   * @param {TwingSource} from The source that initiated the template loading
+   *
+   * @returns {Promise<boolean>} true if the template is fresh, false otherwise
+   *
+   * @throws TwingErrorLoader When name is not found
+   */
+  isFresh(name, time, from) {
+    return Promise.resolve(this.patterns.has(name) ? true : false);
+  }
+
+  /**
+   * Check if we have the source code of a template, given its name.
+   *
+   * @param {string} name The name of the template to check if we can load
+   * @param {TwingSource} from The source that initiated the template loading
+   *
+   * @returns {Promise<boolean>} If the template source code is handled by this loader or not
+   */
+  exists(name, from) {
+    return Promise.resolve(this.patterns.has(name) ? true : false);
+  }
+
+  /**
+   * Resolve the path of a template, given its name, whatever it means in the context of the loader.
+   *
+   * @param {string} name The name of the template to resolve
+   * @param {TwingSource} from The source that initiated the template loading
+   *
+   * @returns {Promise<string>} The resolved path of the template
+   */
+  resolve(name, from) {
+    pattern = this.patterns.get(name);
+    return null;
+  }
+}
+
+const fileSystemLoader = new TwingLoaderFilesystem();
+const patternLabLoader = new TwingLoaderPatternLab();
+const chainLoader = new TwingLoaderChain([fileSystemLoader, patternLabLoader]);
+const twing = new TwingEnvironment(chainLoader);
+var metaPath;
 
 var engine_twig = {
-  engine: Twig,
+  engine: twing,
   engineName: 'twig',
   engineFileExtension: '.twig',
 
-  //Important! Needed for Twig compilation. Can't resolve paths otherwise.
-  expandPartials: true,
-
   // regexes, stored here so they're only compiled once
   findPartialsRE: /{%\s*(?:extends|include|embed)\s+('[^']+'|"[^"]+").*?%}/g,
   findPartialKeyRE: /"((?:\\.|[^"\\])*)"/,
   findListItemsRE: /({{#( )?)(list(I|i)tems.)(one|two|three|four|five|six|seven|eight|nine|ten|eleven|twelve|thirteen|fourteen|fifteen|sixteen|seventeen|eighteen|nineteen|twenty)( )?}}/g, // TODO
 
   // render it
-  renderPattern: function renderPattern(pattern, data) {
-    return Promise.resolve(
-      twig(
-        pattern.relPath,
-        {
-          root: path.relative(
-            __dirname,
-            path.resolve(process.cwd(), 'source', '_patterns')
-          ),
-          context: data,
-        },
-        (error, template) => {
-          if (error) {
-            console.log(error);
-          }
-          console.log(template);
-          return template;
-        }
-      )
+  renderPattern: function renderPattern(pattern, data, partials) {
+    var patternPath = pattern.relPath;
+    if (patternPath.lastIndexOf(metaPath) === 0) {
+      patternPath = patternPath.substring(metaPath.length + 1);
+    }
+    return Promise.resolve(twing.render(patternPath, data));
+  },
+
+  registerPartial: function registerPartial(pattern) {
+    console.log(
+      `registerPartial(${pattern.name} - ${pattern.patternPartial} - ${pattern.patternPath} - ${pattern.relPath})`
     );
+    patternLabLoader.registerPartial(pattern);
   },
 
   // find and return any {% include 'template-name' %} within pattern
@@ -88,7 +170,6 @@ var engine_twig = {
   // given a pattern, and a partial string, tease out the "pattern key" and
   // return it.
   findPartial: function(partialString) {
-    //var partialKey = partialString.replace(this.findPartialsRE, '$1');
     var partial = partialString.match(this.findPartialKeyRE)[0];
     partial = partial.replace(/"/g, '');
 
@@ -121,6 +202,30 @@ var engine_twig = {
     this.spawnFile(config, '_00-head.twig');
     this.spawnFile(config, '_01-foot.twig');
   },
+
+  /**
+   * Accept a Pattern Lab config object from the core and use the settings to
+   * load helpers.
+   *
+   * @param {object} config - the global config object from core
+   */
+  usePatternLabConfig: function(config) {
+    metaPath = path.resolve(config.paths.source.meta);
+    // Global paths
+    fileSystemLoader.addPath(config.paths.source.meta);
+    fileSystemLoader.addPath(config.paths.source.patterns);
+    // Namespaced paths
+    if (
+      config['engines'] &&
+      config['engines']['twig'] &&
+      config['engines']['twig']['namespaces']
+    ) {
+      var namespaces = config['engines']['twig']['namespaces'];
+      Object.keys(namespaces).forEach(function(key, index) {
+        fileSystemLoader.addPath(namespaces[key], key);
+      });
+    }
+  },
 };
 
 module.exports = engine_twig;

packages/engine-twig/package.json

@@ -5,7 +5,7 @@
   "main": "lib/engine_twig.js",
   "dependencies": {
     "fs-extra": "0.30.0",
-    "node-twig": "1.1.0"
+    "twing": "4.0.3"
   },
   "keywords": [
     "Pattern Lab",