feat: generate the timestamp of creation and last updated for each doc file (close #258)

docs/guide/custom-themes.md

@@ -28,6 +28,7 @@ This is the value of `$site` of this very website:
   "base": "/",
   "pages": [
     {
+      "lastModified": 1524027677,
       "path": "/",
       "title": "VuePress",
       "frontmatter": {}
@@ -43,7 +44,8 @@ This is the `$page` object for this page you are looking at:
 
 ``` json
 {
-  "path": "/custom-themes.html",
+  "lastModified": 1524847549,
+  "path": "/guide/custom-themes.html",
   "title": "Custom Themes",
   "headers": [/* ... */],
   "frontmatter": {}
@@ -54,6 +56,10 @@ If the user provided `themeConfig` in `.vuepress/config.js`, it will also be ava
 
 Finally, don't forget that `this.$route` and `this.$router` are also available as part of Vue Router's API.
 
+::: tip
+  `lastModified` is the UNIX timestamp of this file's last git commit, so please ensure you have git installed.
+:::
+
 ## Content Excerpt
 
 If a markdown file contains a `<!-- more -->` comment, any content above the comment will be extracted and exposed as `$page.excerpt`. If you are building custom theme for blogging, this data can be used to render a post list with excerpts.

docs/zh/guide/custom-themes.md

@@ -28,6 +28,7 @@ VuePress 使用单文件组件来构建自定义主题。想要开发一个自
   "base": "/",
   "pages": [
     {
+      "lastModified": 1524027677,
       "path": "/",
       "title": "VuePress",
       "frontmatter": {}
@@ -43,6 +44,7 @@ VuePress 使用单文件组件来构建自定义主题。想要开发一个自
 
 ``` json
 {
+  "lastModified": 1524847549,
   "path": "/custom-themes.html",
   "title": "自定义主题",
   "headers": [/* ... */],
@@ -54,6 +56,10 @@ VuePress 使用单文件组件来构建自定义主题。想要开发一个自
 
 最后，别忘了，作为 Vue Router API 的一部分，`this.$route` 和 `this.$router` 同样可以使用。
 
+::: tip 提示
+  `lastModified` 是这个文件最后一次 git 提交的 unix 时间戳，所以请确保你已经安装了 git。
+:::
+
 ## 内容摘抄
 
 如果一个 markdown 文件中有一个 `<!-- more -->` 注释，则该注释之前的内容会被抓取并暴露在 `$page.excerpt` 属性中。如果你在开发一个博客主题，你可以用这个属性来渲染一个带摘抄的文章列表。

lib/prepare.js

@@ -5,7 +5,12 @@ const yamlParser = require('js-yaml')
 const tomlParser = require('toml')
 const createMarkdown = require('./markdown')
 const tempPath = path.resolve(__dirname, 'app/.temp')
-const { inferTitle, extractHeaders, parseFrontmatter } = require('./util')
+const {
+  inferTitle,
+  extractHeaders,
+  parseFrontmatter,
+  getGitLastModifiedTimeStamp
+} = require('./util')
 
 fs.ensureDirSync(tempPath)
 
@@ -178,12 +183,15 @@ async function resolveOptions (sourceDir) {
 
   // resolve pagesData
   const pagesData = await Promise.all(pageFiles.map(async (file) => {
+    const filepath = path.resolve(sourceDir, file)
+    const lastModified = getGitLastModifiedTimeStamp(filepath)
     const data = {
+      lastModified,
       path: fileToPath(file)
     }
 
     // extract yaml frontmatter
-    const content = await fs.readFile(path.resolve(sourceDir, file), 'utf-8')
+    const content = await fs.readFile(filepath, 'utf-8')
     const frontmatter = parseFrontmatter(content)
     // infer title
     const title = inferTitle(frontmatter)

lib/util/index.js

@@ -1,3 +1,4 @@
+const spawn = require('cross-spawn')
 const parseHeaders = require('./parseHeaders')
 
 exports.normalizeHeadTag = tag => {
@@ -81,3 +82,7 @@ exports.extractHeaders = (content, include = [], md) => {
   cache.set(key, res)
   return res
 }
+
+exports.getGitLastModifiedTimeStamp = filepath => {
+  return parseInt(spawn.sync('git', ['log', '-1', '--format=%ct', filepath]).stdout.toString('utf-8'))
+}

package.json

@@ -45,6 +45,7 @@
     "commander": "^2.15.1",
     "connect-history-api-fallback": "^1.5.0",
     "copy-webpack-plugin": "^4.5.1",
+    "cross-spawn": "^6.0.5",
     "css-loader": "^0.28.11",
     "diacritics": "^1.3.0",
     "docsearch.js": "^2.5.2",

yarn.lock

@@ -1374,6 +1374,16 @@ cross-spawn@^5.0.1, cross-spawn@^5.1.0:
     shebang-command "^1.2.0"
     which "^1.2.9"
 
+cross-spawn@^6.0.5:
+  version "6.0.5"
+  resolved "https://registry.yarnpkg.com/cross-spawn/-/cross-spawn-6.0.5.tgz#4a5ec7c64dfae22c3a14124dbacdee846d80cbc4"
+  dependencies:
+    nice-try "^1.0.4"
+    path-key "^2.0.1"
+    semver "^5.5.0"
+    shebang-command "^1.2.0"
+    which "^1.2.9"
+
 [email protected]:
   version "2.0.5"
   resolved "https://registry.yarnpkg.com/cryptiles/-/cryptiles-2.0.5.tgz#3bdfecdc608147c1c67202fa291e7dca59eaa3b8"
@@ -4284,6 +4294,10 @@ neo-async@^2.5.0:
   version "2.5.1"
   resolved "https://registry.yarnpkg.com/neo-async/-/neo-async-2.5.1.tgz#acb909e327b1e87ec9ef15f41b8a269512ad41ee"
 
+nice-try@^1.0.4:
+  version "1.0.4"
+  resolved "https://registry.yarnpkg.com/nice-try/-/nice-try-1.0.4.tgz#d93962f6c52f2c1558c0fbda6d512819f1efe1c4"
+
 no-case@^2.2.0:
   version "2.3.2"
   resolved "https://registry.yarnpkg.com/no-case/-/no-case-2.3.2.tgz#60b813396be39b3f1288a4c1ed5d1e7d28b464ac"
@@ -4686,7 +4700,7 @@ path-is-inside@^1.0.1, path-is-inside@^1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/path-is-inside/-/path-is-inside-1.0.2.tgz#365417dede44430d1c11af61027facf074bdfc53"
 
-path-key@^2.0.0:
+path-key@^2.0.0, path-key@^2.0.1:
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/path-key/-/path-key-2.0.1.tgz#411cadb574c5a140d3a4b1910d40d80cc9f40b40"