feat(meta patterns): Async support

Author: bmuenzenmeyer

core/index.js

@@ -22,7 +22,9 @@ const pe = require('./lib/pattern_exporter');
 const lh = require('./lib/lineage_hunter');
 const markModifiedPatterns = require('./lib/markModifiedPatterns');
 const parseAllLinks = require('./lib/parseAllLinks');
-const renderSync = require('./lib/renderSync');
+const processMetaPattern = require('./lib/processMetaPattern');
+const render = require('./lib/render');
+const Pattern = require('./lib/object_factory').Pattern;
 
 const defaultConfig = require('../patternlab-config.json');
 
@@ -40,7 +42,6 @@ updateNotifier({
   updateCheckInterval: 1000 * 60 * 60 * 24 // notify at most once a day
 }).notify();
 
-
 /**
  * Returns the standardized default config
  *
@@ -186,73 +187,85 @@ const patternlab_module = function (config) {
       patternlab.processAllPatternsRecursive(paths.source.patterns, patternlab);
 
       //take the user defined head and foot and process any data and patterns that apply
-      // GTP: should these really be invoked from outside?
-      // TODO: should these be wrapped in promises?
-      patternlab.processHeadPattern();
-      patternlab.processFootPattern();
-
-      //cascade any patternStates
-      lineage_hunter.cascade_pattern_states(patternlab);
-
-      //set pattern-specific header if necessary
-      let head;
-      if (patternlab.userHead) {
-        head = patternlab.userHead;
-      } else {
-        head = patternlab.header;
-      }
-
-      //set the pattern-specific header by compiling the general-header with data, and then adding it to the meta header
-      patternlab.data.patternLabHead = renderSync(patternlab.header, {
-        cacheBuster: patternlab.cacheBuster
-      });
-
-      // If deletePatternDir == true or graph needs to be updated
-      // rebuild all patterns
-      let patternsToBuild = null;
+      const headPatternPromise = processMetaPattern(`_00-head.${patternlab.config.patternExtension}`, 'userHead', patternlab);
+      const footPatternPromise = processMetaPattern(`_01-foot.${patternlab.config.patternExtension}`, 'userFoot', patternlab);
 
-      // If deletePatternDir == true or graph needs to be updated
-      // rebuild all patterns
-      patternsToBuild = null;
+      return Promise.all([headPatternPromise, footPatternPromise]).then(() => {
 
-      if (patternlab.incrementalBuildsEnabled) {
-        // When the graph was loaded from file, some patterns might have been moved/deleted between runs
-        // so the graph data become out of sync
-        patternlab.graph.sync().forEach(n => {
-          logger.info("[Deleted/Moved] " + n);
-        });
+        //cascade any patternStates
+        lineage_hunter.cascade_pattern_states(patternlab);
 
-        // TODO Find created or deleted files
-        const now = new Date().getTime();
-        markModifiedPatterns(now, patternlab);
-        patternsToBuild = patternlab.graph.compileOrder();
-      } else {
-        // build all patterns, mark all to be rebuilt
-        patternsToBuild = patternlab.patterns;
-        for (const p of patternsToBuild) {
-          p.compileState = CompileState.NEEDS_REBUILD;
+        //set pattern-specific header if necessary
+        let head;
+        if (patternlab.userHead) {
+          head = patternlab.userHead;
+        } else {
+          head = patternlab.header;
         }
-      }
 
-      //render all patterns last, so lineageR works
-      return patternsToBuild
-        .reduce((previousPromise, pattern) => {
-          return previousPromise.then(() => patternlab.renderSinglePattern(pattern, head));
-        }, Promise.resolve())
-        .then(() => {
-          // Saves the pattern graph when all files have been compiled
-          PatternGraph.storeToFile(patternlab);
-          if (patternlab.config.exportToGraphViz) {
-            PatternGraph.exportToDot(patternlab, "dependencyGraph.dot");
-            logger.info(`Exported pattern graph to ${path.join(config.paths.public.root, "dependencyGraph.dot")}`);
+        //set the pattern-specific header by compiling the general-header with data, and then adding it to the meta header
+        return render(Pattern.createEmpty({extendedTemplate: patternlab.header}), {
+          cacheBuster: patternlab.cacheBuster
+        }).then((results) => {
+          patternlab.data.patternLabHead = results;
+
+          // If deletePatternDir == true or graph needs to be updated
+          // rebuild all patterns
+          let patternsToBuild = null;
+
+          // If deletePatternDir == true or graph needs to be updated
+          // rebuild all patterns
+          patternsToBuild = null;
+
+          if (patternlab.incrementalBuildsEnabled) {
+            // When the graph was loaded from file, some patterns might have been moved/deleted between runs
+            // so the graph data become out of sync
+            patternlab.graph.sync().forEach(n => {
+              logger.info("[Deleted/Moved] " + n);
+            });
+
+            // TODO Find created or deleted files
+            const now = new Date().getTime();
+            markModifiedPatterns(now, patternlab);
+            patternsToBuild = patternlab.graph.compileOrder();
+          } else {
+            // build all patterns, mark all to be rebuilt
+            patternsToBuild = patternlab.patterns;
+            for (const p of patternsToBuild) {
+              p.compileState = CompileState.NEEDS_REBUILD;
+            }
           }
 
-          //export patterns if necessary
-          pattern_exporter.export_patterns(patternlab);
+          //render all patterns last, so lineageR works
+          return patternsToBuild
+            .reduce((previousPromise, pattern) => {
+              return previousPromise.then(() => patternlab.renderSinglePattern(pattern, head));
+            }, Promise.resolve())
+            .then(() => {
+              // Saves the pattern graph when all files have been compiled
+              PatternGraph.storeToFile(patternlab);
+              if (patternlab.config.exportToGraphViz) {
+                PatternGraph.exportToDot(patternlab, "dependencyGraph.dot");
+                logger.info(`Exported pattern graph to ${path.join(config.paths.public.root, "dependencyGraph.dot")}`);
+              }
+
+              //export patterns if necessary
+              pattern_exporter.export_patterns(patternlab);
+            });
+
+        }).catch((reason) => {
+          console.log(reason);
+          logger.error('Error rendering pattern lab header');
         });
-    }).catch((err) => {
-      console.log(err);
-      logger.info('Error in buildPatterns()');
+
+      }).catch((reason) => {
+        console.log(reason);
+        logger.error('Error processing meta patterns');
+      });
+
+    }).catch((reason) => {
+      console.log(reason);
+      logger.error('Error in buildPatterns()');
     });
   }
 

core/lib/patternlab.js

@@ -11,7 +11,6 @@ const pm = require('./plugin_manager');
 const packageInfo = require('../../package.json');
 const buildListItems = require('./buildListItems');
 const dataLoader = require('./data_loader')();
-const decompose = require('./decompose');
 const logger = require('./log');
 const processIterative = require('./processIterative');
 const processRecursive = require('./processRecursive');
@@ -210,58 +209,6 @@ module.exports = class PatternLab {
     starterkit_manager.load_starterkit(starterkitName, clean);
   }
 
-
-  // Pattern processing methods
-
-  /**
-   * Process the user-defined pattern head and prepare it for rendering
-   */
-  processHeadPattern() {
-    try {
-      const headPath = path.resolve(this.config.paths.source.meta, '_00-head.mustache');
-      const headPattern = new Pattern(headPath, null, this);
-      headPattern.template = fs.readFileSync(headPath, 'utf8');
-      headPattern.isPattern = false;
-      headPattern.isMetaPattern = true;
-      decompose(headPattern, this, true).then(() => {
-        this.userHead = headPattern.extendedTemplate;
-      });
-    }
-    catch (ex) {
-      logger.warning(`Could not find the user-editable header template, currently configured to be at ${path.join(this.config.paths.source.meta, '_00-head.ext')}. Your configured path may be incorrect (check this.config.paths.source.meta in your config file), the file may have been deleted, or it may have been left in the wrong place during a migration or update.`);
-      logger.warning(ex);
-
-      // GTP: it seems increasingly naughty as we refactor to just unilaterally do this here,
-      // but whatever. For now.
-      process.exit(1);
-    }
-  }
-
-  /**
-   * Process the user-defined pattern footer and prepare it for rendering
-   */
-  processFootPattern() {
-    try {
-      const footPath = path.resolve(this.config.paths.source.meta, '_01-foot.mustache');
-      const footPattern = new Pattern(footPath, null, this);
-      footPattern.template = fs.readFileSync(footPath, 'utf8');
-      footPattern.isPattern = false;
-      footPattern.isMetaPattern = true;
-      decompose(footPattern, this, true).then(() => {
-        this.userFoot = footPattern.extendedTemplate;
-      });
-    }
-    catch (ex) {
-      logger.error(`Could not find the user-editable footer template, currently configured to be at ${path.join(this.config.paths.source.meta, '_01-foot.ext')}. Your configured path may be incorrect (check this.config.paths.source.meta in your config file), the file may have been deleted, or it may have been left in the wrong place during a migration or update.`);
-      logger.warning(ex);
-
-      // GTP: it seems increasingly naughty as we refactor to just unilaterally do this here,
-      // but whatever. For now.
-      process.exit(1);
-    }
-  }
-
-
   // info methods
   getVersion() {
     return this.package.version;
@@ -367,7 +314,7 @@ module.exports = class PatternLab {
     pattern.header = head;
 
     // const headHTML
-    const headPromise = Promise.resolve(render(Pattern.createEmpty({extendedTemplate: pattern.header}), allData));
+    const headPromise = render(Pattern.createEmpty({extendedTemplate: pattern.header}), allData);
 
     ///////////////
     // PATTERN
@@ -417,11 +364,11 @@ module.exports = class PatternLab {
 
     //set the pattern-specific footer by compiling the general-footer with data, and then adding it to the meta footer
     // footerPartial
-    const footerPartialPromise = Promise.resolve(render(Pattern.createEmpty({extendedTemplate: this.footer}), {
+    const footerPartialPromise = render(Pattern.createEmpty({extendedTemplate: this.footer}), {
       isPattern: pattern.isPattern,
       patternData: pattern.patternData,
       cacheBuster: this.cacheBuster
-    }));
+    });
 
     const self = this;
 

core/lib/processMetaPattern.js

@@ -0,0 +1,24 @@
+"use strict";
+
+const path = require('path');
+
+const Pattern = require('./object_factory').Pattern;
+const decompose = require('./decompose');
+const logger = require('./log');
+
+//this may be mocked in unit tests, so let it be overridden
+let fs = require('fs-extra'); // eslint-disable-line
+
+module.exports = function (fileName, metaType, patternlab) {
+  const metaPath = path.resolve(patternlab.config.paths.source.meta, fileName);
+  const metaPattern = new Pattern(metaPath, null, patternlab);
+  metaPattern.template = fs.readFileSync(metaPath, 'utf8');
+  metaPattern.isPattern = false;
+  metaPattern.isMetaPattern = true;
+  return decompose(metaPattern, patternlab, true).then(() => {
+    patternlab[metaType] = metaPattern.extendedTemplate;
+  }).catch((reason) => {
+    logger.warning(`Could not find the user-editable template ${fileName}, currently configured to be at ${patternlab.config.paths.source.meta}. Your configured path may be incorrect (check paths.source.meta in your config file), the file may have been deleted, or it may have been left in the wrong place during a migration or update.`);
+    logger.warning(reason);
+  });
+};