Make PR fixes

Author: jamos-tay

docs/userGuide/usingPlugins.md

@@ -11,12 +11,16 @@
 
 A plugin is a user defined extension that can add custom features to MarkBind. Markbind plugins are `js` scripts that are loaded and run during the page generation.
 
+**WARNING:** Plugins are executable programs. This means that they might contain malicious code that may damage your computer.
+
+Only run plugins from people that you trust. Do not run the plugin if the source/origin of the plugin cannot be ascertained.
+
 ### Adding Plugins
 
-Plugins are stored in the `_markbind/plugins` folder which is generated on `init`. To use a plugin, place the `js` file in the `_markbind/plugins` folder and add the following options to the site configuration:
+Plugins are stored in the `_markbind/plugins` folder which is generated on `init`. To use a plugin, place the `js` source of the plugin in the `_markbind/plugins` folder and add the following options to `site.json`:
 
 - `plugins`: An array of plugin names to use
-- `context`: An object mapping plugin name to data provided to the plugin. Each plugin can have its own custom data.
+- `context`: An object containing lists of parameters passed to each individual plugin.
 
 For example:
 
@@ -42,8 +46,8 @@ MarkBind plugins allow the user to mutate the page data (`html`) during the page
 
 MarkBind provides two entry points for modifying the page:
 
-- Prerender: Called before any markbind rendering is done on the site. Markbind rendering refers to the conversion of markdown to valid HTML.
-- Postrender: Called after all markbind rendering is done on the site.
+- Prerender: Called before MarkBind converts/renders the source from markdown to HTML.
+- Postrender: Called after the HTML is rendered.
 
 These are controlled by specifying the `preRender` and `postRender` functions in the plugin `js`. Each function takes in two parameters:
 
@@ -52,9 +56,9 @@ These are controlled by specifying the `preRender` and `postRender` functions in
   -  For `postRender`, `content` will be the compiled `.html` file.
 - `siteContext`: Any other data to be provided to the plugin. This can be specified in the `site.json`.
 
-Markbind will call these two functions with the respective content, and retrieve a string data that is used for the next step of the compilation process.
+MarkBind will call these two functions with the respective content, and retrieve a string data that is used for the next step of the compilation process.
 
-A plugin will typically follow a format similar to this one:
+An example of a plugin is shown below. The plugin appends a paragraph of text to a specific div in the markdown files:
 
 ```js
 // myPlugin.js
@@ -80,7 +84,7 @@ module.exports = {
     "myPlugin"
   ],
   "context" : {
-    "plugin1" : {
+    "myPlugin" : {
       "post" : "<p>Hello</p>"
     }
   }
@@ -94,6 +98,4 @@ module.exports = {
 <div id="my-div"></div>
 ```
 
-The above plugin appends a paragraph of text to a div in the `index.md`.
-
 </div>

lib/Site.js

@@ -585,8 +585,13 @@ Site.prototype.collectPlugins = function () {
     return;
   }
   this.siteConfig.plugins.forEach((plugin) => {
+    const pluginPath = path.join(this.rootPath, PLUGIN_FOLDER_PATH, `${plugin}.js`);
+    if (!fs.existsSync(pluginPath)) {
+      logger.warn(`Unable to load plugin ${plugin}, skipping`);
+      return;
+    }
     // eslint-disable-next-line global-require, import/no-dynamic-require
-    this.loadedPlugins[plugin] = require(path.join(this.rootPath, PLUGIN_FOLDER_PATH, `${plugin}.js`));
+    this.loadedPlugins[plugin] = require(pluginPath);
   });
 };
 

test/test_site/expected/index.html

@@ -297,7 +297,7 @@ <h2 id="panel-content-inside-unexpanded-panel-should-not-appear-in-search-data">
       </panel>
       <h1 id="div-for-plugins">Div for plugins<a class="fa fa-anchor" href="#div-for-plugins"></a></h1>
       <div id="test-plugins">
-        <p>Prerender</p>
+        <h2>Prerender<a class="fa fa-anchor" href="#undefined"></a></h2>
         <p>Postrender</p>
       </div>
     </div>

test/test_site/expected/siteData.json

@@ -55,7 +55,8 @@
         "panel-with-src-from-another-markbind-site": "Panel with src from another Markbind site",
         "modal-with-panel-inside": "Modal with panel inside",
         "unexpanded-panel": "Unexpanded panel",
-        "div-for-plugins": "Div for plugins"
+        "div-for-plugins": "Div for plugins",
+        "undefined": "Prerender"
       },
       "title": "Hello World",
       "footer": "footer.md",

test/test_site/site.json

@@ -40,7 +40,7 @@
   ],
   "context" : {
     "testPlugin" : {
-        "pre": "<p>Prerender</p>",
+        "pre": "<h2>Prerender</h2>",
         "post": "<p>Postrender</p>"
     }
   }