node to page: Refactor the build process

To make it easier to follow and understand.

Both building and rebuilding now follow a four step flow:

1. Init
2. Process
3. Assemble
4. Render

And now there are only one Build method, used for both builds and rebuilds.

Updates #2297

1 files changed, 197 insertions, 0 deletions

diff --git a/hugolib/hugo_sites_build.go b/hugolib/hugo_sites_build.go
new file mode 100644
index 000000000..f5b6e6809
--- /dev/null
+++ b/hugolib/hugo_sites_build.go
@@ -0,0 +1,197 @@
+// Copyright 2016-present The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package hugolib
+
+import (
+	"time"
+
+	"errors"
+
+	"github.com/fsnotify/fsnotify"
+	"github.com/spf13/hugo/helpers"
+	jww "github.com/spf13/jwalterweatherman"
+)
+
+// Build builds all sites. If filesystem events are provided,
+// this is considered to be a potential partial rebuild.
+func (h *HugoSites) Build(config BuildCfg, events ...fsnotify.Event) error {
+	t0 := time.Now()
+
+	// Need a pointer as this may be modified.
+	conf := &config
+
+	if conf.whatChanged == nil {
+		// Assume everything has changed
+		conf.whatChanged = &whatChanged{source: true, other: true}
+	}
+
+	if len(events) > 0 {
+		// Rebuild
+		if err := h.initRebuild(conf); err != nil {
+			return err
+		}
+	} else {
+		if err := h.init(conf); err != nil {
+			return err
+		}
+	}
+
+	if err := h.process(conf, events...); err != nil {
+		return err
+	}
+
+	if err := h.assemble(conf); err != nil {
+		return err
+	}
+
+	if err := h.render(conf); err != nil {
+		return err
+	}
+
+	if config.PrintStats {
+		jww.FEEDBACK.Printf("total in %v ms\n", int(1000*time.Since(t0).Seconds()))
+	}
+
+	return nil
+
+}
+
+// Build lifecycle methods below.
+// The order listed matches the order of execution.
+
+func (h *HugoSites) init(config *BuildCfg) error {
+
+	for _, s := range h.Sites {
+		if s.PageCollections == nil {
+			s.PageCollections = newPageCollections()
+		}
+	}
+
+	if config.ResetState {
+		h.reset()
+	}
+
+	if config.CreateSitesFromConfig {
+		if err := h.createSitesFromConfig(); err != nil {
+			return err
+		}
+	}
+
+	h.runMode.Watching = config.Watching
+
+	return nil
+}
+
+func (h *HugoSites) initRebuild(config *BuildCfg) error {
+	if config.CreateSitesFromConfig {
+		return errors.New("Rebuild does not support 'CreateSitesFromConfig'.")
+	}
+
+	if config.ResetState {
+		return errors.New("Rebuild does not support 'ResetState'.")
+	}
+
+	if !config.Watching {
+		return errors.New("Rebuild called when not in watch mode")
+	}
+
+	h.runMode.Watching = config.Watching
+
+	for _, s := range h.Sites {
+		s.resetBuildState()
+	}
+
+	helpers.InitLoggers()
+
+	return nil
+}
+
+func (h *HugoSites) process(config *BuildCfg, events ...fsnotify.Event) error {
+	// We should probably refactor the Site and pull up most of the logic from there to here,
+	// but that seems like a daunting task.
+	// So for now, if there are more than one site (language),
+	// we pre-process the first one, then configure all the sites based on that.
+	firstSite := h.Sites[0]
+
+	if len(events) > 0 {
+		// This is a rebuild
+		changed, err := firstSite.reProcess(events)
+		config.whatChanged = &changed
+		return err
+	}
+
+	return firstSite.process(*config)
+
+}
+
+func (h *HugoSites) assemble(config *BuildCfg) error {
+	// TODO(bep) np we could probably wait and do this in one go later
+	h.setupTranslations()
+
+	if len(h.Sites) > 1 {
+		// The first is initialized during process; initialize the rest
+		for _, site := range h.Sites[1:] {
+			site.initializeSiteInfo()
+		}
+	}
+
+	if config.whatChanged.source {
+		h.assembleGitInfo()
+
+		for _, s := range h.Sites {
+			if err := s.buildSiteMeta(); err != nil {
+				return err
+			}
+		}
+	}
+
+	if err := h.createMissingNodes(); err != nil {
+		return err
+	}
+
+	for _, s := range h.Sites {
+		s.refreshPageCaches()
+		s.setupPrevNext()
+	}
+
+	if err := h.assignMissingTranslations(); err != nil {
+		return err
+	}
+
+	if err := h.preRender(*config, whatChanged{source: true, other: true}); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (h *HugoSites) render(config *BuildCfg) error {
+	if !config.SkipRender {
+		for _, s := range h.Sites {
+			if err := s.render(); err != nil {
+				return err
+			}
+
+			if config.PrintStats {
+				s.Stats()
+			}
+		}
+
+		if err := h.renderCrossSitesArtifacts(); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}