1.0.1 & demo

Author: limdongjin

.gitignore

@@ -1,3 +1,4 @@
+yarn.lock
 .idea
 # Logs
 logs

.npmignore

@@ -1,3 +1,4 @@
 .DS_Store
 .git*
 .idea
+demo

README.md

@@ -103,15 +103,15 @@ module.exports = {
 - Default: `undefined`
 
 ```html
-<meta name="twitter:creator" content="@genilcoder">
+<meta name="twitter:creator" content="@limdongjin">
 ```
 
 ### default_twitter_site
 
 - Default: `undefined`
 
 ```html
-<meta name="twitter:site" content="@genilcoder">
+<meta name="twitter:site" content="@limdongjin">
 ```
 
 ### default_twitter_card
@@ -188,14 +188,18 @@ if you are not write frontmatter title, create meta title tag from $page.title.
 
 ### twitter_creator
 
+- Example: twituser
+
 ```html
-<meta name="twitter:creator" content="@genilcoder">
+<meta name="twitter:creator" content="@twituser">
 ```
 
 ### twitter_site
 
+- Example: twituser
+
 ```html
-<meta name="twitter:site" content="@genilcoder">
+<meta name="twitter:site" content="@twituser">
 ```
 
 ### twitter_card

demo/.vuepress/config.js

@@ -0,0 +1,11 @@
+module.exports = {
+    title: 'simple seo plugin demo',
+    description: 'Welcome Contributes',
+    plugins: [ require('./plugins/my-plugin'), {
+        default_image: '/image.jpg',
+        root_url: 'https://limdongjin.github.io',
+        default_site_name: 'limdongjin TIL',
+        default_twitter_creator: '@twituser',
+        default_twitter_site: '@twituser'
+    }]
+}

demo/.vuepress/plugins/my-plugin.js

@@ -0,0 +1,292 @@
+const { path } = require('@vuepress/shared-utils');
+
+module.exports = (options = {}, context) => ({
+    extendPageData($page) {
+        const {
+            frontmatter,
+            path
+        } = $page;
+
+        let root_url = options.root_url || "";
+        if(frontmatter.root_url){
+            root_url = frontmatter.root_url
+        }
+        const full_url = root_url + path;
+
+        const is_duplicate_og = property => has_property(frontmatter, property);
+        const is_duplicate_tw = name => has_name(frontmatter, name);
+        const is_duplicate_ite = ite => has_itemprop(frontmatter, ite);
+
+        const push_og = (property, content) => frontmatter.meta.push(og_template(property, content));
+        const push_twit = (name, content) =>frontmatter.meta.push(twitter_template(name, content));
+
+        const image_seo = (options = {}, frontmatter) => {
+            const {
+                default_image,
+                default_image_type,
+                default_image_width,
+                default_image_height,
+                default_image_alt
+            } = options;
+
+            const {
+                image,
+                image_type,
+                image_width,
+                image_height,
+                image_alt
+            } = frontmatter;
+
+            let default_image_full_path;
+            if (default_image)
+                default_image_full_path = root_url + default_image;
+
+            // Default
+            if (!is_duplicate_og('og:image') && !image) {
+                const push_og_image_default = {
+                    'og:image': default_image_full_path,
+                    'og:image:type': default_image_type,
+                    'og:image:width': default_image_width,
+                    'og:image:height': default_image_height,
+                    'og:image:alt': default_image_alt
+                };
+
+                Object.keys(push_og_image_default).forEach((property)=>{
+                    if (!is_duplicate_og(property) && push_og_image_default[property])
+                        push_og(property, push_og_image_default[property])
+                })
+
+                if (!is_duplicate_tw('twitter:image') && !image) // case. image empty
+                    push_twit('twitter:image', default_image_full_path);
+            }
+
+            // frontmatter
+            if (image) {
+                const push_og_image_front = {
+                    'og:image': image,
+                    'og:image:type': image_type,
+                    'og:image:width': image_width,
+                    'og:image:height': image_height,
+                    'og:image:alt': image_alt
+                }
+                Object.keys(push_og_image_front).forEach((property)=>{
+                    if (!is_duplicate_og(property)) push_og(property, push_og_image_front[property]);
+                })
+
+                if (!is_duplicate_tw('twitter:image')) push_twit('twitter:image', image)
+                if (!is_duplicate_ite( 'image'))
+                    frontmatter.meta.push(itemprop_template('image', image))
+            }
+        };
+
+
+        const description_seo = () => {
+            const {
+                description
+            } = frontmatter
+            let meta_description = find_meta_description(frontmatter);
+
+            if (description) {
+                console.log('fr')
+                if (!is_duplicate_og('og:description'))
+                    push_og('og:description', description);
+                if (!is_duplicate_tw( 'twitter:description'))
+                    push_twit('twitter:description', description);
+                if (!meta_description)
+                    frontmatter.meta.push({'name': 'description', 'content': description});
+                if (!is_duplicate_ite( 'description'))
+                    frontmatter.meta.push(itemprop_template('description', description))
+            }
+            meta_description = find_meta_description(frontmatter);
+
+            if (meta_description) {
+                console.log('meta')
+                if (!is_duplicate_og('og:description')) {
+                    console.log("og")
+                    push_og('og:description', meta_description);
+                }
+                if (!is_duplicate_tw('twitter:description'))
+                    push_twit('twitter:description', meta_description);
+                if (!is_duplicate_ite( 'description'))
+                    frontmatter.meta.push(itemprop_template('description', meta_description))
+            }
+        };
+
+        const url_seo = () => {
+            if (!is_duplicate_og('og:url'))
+                push_og('og:url', full_url);
+            if (!has_name(frontmatter, 'twitter:url'))
+                push_twit('twitter:url', full_url)
+        };
+
+        const title_seo = () => {
+            const {title} = $page
+            if(frontmatter.title){
+                if (!is_duplicate_og('og:title'))
+                    push_og('og:title', frontmatter.title);
+                if (!is_duplicate_tw('twitter:title'))
+                    push_twit('twitter:title', frontmatter.title);
+                if (!is_duplicate_ite('name'))
+                    frontmatter.meta.push(itemprop_template('name', frontmatter.title))
+                return
+            }
+
+            if (!is_duplicate_og('og:title'))
+                push_og('og:title', title);
+            if (!is_duplicate_tw('twitter:title'))
+                push_twit('twitter:title', title);
+            if (!is_duplicate_ite('name'))
+                frontmatter.meta.push(itemprop_template('name', title))
+        };
+
+        const twitter_creator_seo = () => {
+            const {default_twitter_creator}=options
+            const {twitter_creator} = frontmatter
+            let creator;
+            if (is_duplicate_tw('twitter:creator')) return
+
+            if (twitter_creator) {
+                if(!twitter_creator.includes("@")){
+                    creator = "@"+twitter_creator
+                }else{
+                    creator = twitter_creator
+                }
+                push_twit('twitter:creator', creator);
+            }
+            else if (default_twitter_creator) {
+                if(!twitter_creator.includes("@")) {
+                    creator = "@"+default_twitter_creator
+                }else{
+                    creator = default_twitter_creator
+                }
+                push_twit('twitter:creator', creator)
+            }
+        };
+
+        const og_type_seo = () => {
+            const {og_type} = frontmatter
+            let default_og_type = options.default_og_type || "article";
+
+            if (is_duplicate_og('og:type')) return
+
+            if (og_type)
+                push_og('og:type', og_type);
+            else
+                push_og('og:type', default_og_type)
+        };
+
+        const twitter_card_seo = () => {
+            let default_twitter_card = options.default_twitter_card || "summary";
+            const {twitter_card} = frontmatter
+
+            if (!is_duplicate_tw('twitter:card') && twitter_card)
+                push_twit('twitter:card', twitter_card);
+            if (!is_duplicate_tw('twitter:card'))
+                push_twit('twitter:card', default_twitter_card)
+        };
+
+        const site_name_seo = () => {
+            const {default_site_name} = options
+            const {site_name} = frontmatter
+
+            if (!is_duplicate_og('og:site_name') && site_name)
+                push_og('og:site_name', site_name);
+            if (!is_duplicate_og('og:site_name') && default_site_name)
+                push_og('og:site_name', default_site_name)
+        };
+
+        const twitter_site_seo = () => {
+            const {default_twitter_site} = options
+            const {twitter_site} = frontmatter
+            let sit;
+
+            if (!is_duplicate_tw('twitter:site') && twitter_site)
+                if(!twitter_site.includes("@")){
+                    sit = "@"+twitter_site
+                }else{
+                    sit = twitter_site
+                }
+            push_twit('twitter:site', sit);
+            if (!is_duplicate_tw('twitter:site') && default_twitter_site)
+                if(!twitter_site.includes("@")){
+                    sit = "@"+default_twitter_site
+                }else{
+                    sit = default_twitter_site
+                }
+            push_twit('twitter:site', sit)
+        };
+
+        if (!exists_meta(frontmatter)) frontmatter.meta = [];
+        /* IMAGE SEO */
+        image_seo(options, frontmatter);
+        /* DESCRIPTION SEO */
+        description_seo();
+        /* URL SEO */
+        url_seo();
+        /* TITLE SEO */
+        title_seo();
+        /* OG TYPE SEO */
+        og_type_seo();
+        /* TWITTER CARD SEO */
+        twitter_card_seo();
+        /* SITE NAME SEO */
+        site_name_seo();
+        /* TWITTER SITE SEO */
+        twitter_site_seo();
+        /* TWITTER CREATOR SEO */
+        twitter_creator_seo();
+    }
+});
+
+const find_meta_description = frontmatter => {
+    let flag = false;
+    let description = "";
+
+    for (const elem of frontmatter.meta) if (elem.hasOwnProperty('name') && elem.name === 'description') {
+        flag = true;
+        description = elem.content
+    }
+
+    if(flag) return description
+    return flag
+};
+
+const exists_meta = frontmatter => frontmatter.meta !== undefined;
+
+const has_property = (frontmatter, property_name) => {
+    let flag = false;
+    frontmatter.meta.forEach(elem => {
+        if (elem.hasOwnProperty('property') && elem.property === property_name) flag = true;
+    })
+    return flag
+};
+
+const has_name = (frontmatter, name) => {
+    let flag = false;
+    frontmatter.meta.forEach(elem => {
+        if (elem.hasOwnProperty('name') && elem.name === name) flag = true;
+    })
+    return flag
+};
+const has_itemprop = (frontmatter, itemprop) => {
+    let flag = false;
+    frontmatter.meta.forEach(elem => {
+        if (elem.hasOwnProperty('itemprop') && elem.itemprop === itemprop) flag = true;
+    });
+    return flag
+};
+
+const og_template = (property, content) => ({
+    'property': property,
+    'content': content
+});
+
+const twitter_template = (name, content) => ({
+    'name': name,
+    'content': content
+});
+
+const itemprop_template = (itemprop, content) => ({
+    'itemprop': itemprop,
+    'content': content
+});