blocks|key|321499|text|在您的app.js中，您需要添加如下内容|type|unstyled|depth|inlineStyleRanges|entityRanges|data|321500|global.myvar+=+100;|code-block|syntax|javascript|321501|现在，在您想要使用此变量的所有文件中，您只需以myvar的身份访问它|offset|length|style|CODE|321502|entityMap^0|0|0|N|5|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

In your app.js you need add something like this

<pre><code>global.myvar = 100;
</code></pre>

Now, in all your files you want use this variable, you can just access it as <code>myvar</code>

blocks|key|104542|text|对于Express4.0，我发现使用应用程序级变量的工作方式略有不同&Cory的答案对我不起作用。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|104543|来自文档：http://expressjs.com/en/api.html#app.locals|offset|length|104544|我发现你可以在下面的代码中声明一个全局变量|104545|app.locals|code-block|syntax|javascript|104546|e.g|104547|app.locals.baseUrl+=+"http://www.google.com"|104548|然后，您可以在应用程序中访问这些变量&在express中间件中，您可以在请求对象中访问它们，如下所示|104549|req.app.locals.baseUrl|104550|例如：|104551|console.log(req.app.locals.baseUrl)
//prints+out+http://www.google.com|104552|entityMap|0|LINK|mutability|MUTABLE|url|http://expressjs.com/en/api.html#app.locals^0|0|5|17|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|16|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|17|8|@]|9|@$D|18|E|19|1|1A]]|A|$]]|$1|F|3|G|5|6|7|1B|8|@]|9|@]|A|$]]|$1|H|3|I|5|J|7|1C|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|1D|8|@]|9|@]|A|$]]|$1|O|3|P|5|J|7|1E|8|@]|9|@]|A|$K|L]]|$1|Q|3|R|5|6|7|1F|8|@]|9|@]|A|$]]|$1|S|3|T|5|J|7|1G|8|@]|9|@]|A|$K|L]]|$1|U|3|V|5|6|7|1H|8|@]|9|@]|A|$]]|$1|W|3|X|5|J|7|1I|8|@]|9|@]|A|$K|L]]|$1|Y|3|-4|5|6|7|1J|8|@]|9|@]|A|$]]]|Z|$10|$5|11|12|13|A|$14|15]]]]

For Express 4.0 I found that using application level variables works a little differently &amp; Cory's answer did not work for me.

From the docs: <a href="http://expressjs.com/en/api.html#app.locals" rel="noreferrer">http://expressjs.com/en/api.html#app.locals</a>

I found that you could declare a global variable for the app in 

<pre><code>app.locals
</code></pre>

e.g

<pre><code>app.locals.baseUrl = "http://www.google.com"
</code></pre>

And then in your application you can access these variables &amp; in your express middleware you can access them in the req object as

<pre><code>req.app.locals.baseUrl
</code></pre>

e.g.

<pre><code>console.log(req.app.locals.baseUrl)
//prints out http://www.google.com
</code></pre>

blocks|key|104636|text|一种方法是在app.js中更新该应用程序的app.locals变量|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|104637|通过以下方式设置|104638|var+app+=+express();
app.locals.appName+=+"DRC+on+FHIR";|code-block|syntax|javascript|104639|获取/访问|104640|app.listen(3000,+function+()+{
++++console.log('['+%2B+app.locals.appName+%2B+']+=>+app+listening+on+port+3001!');
});|104641|使用@RamRovi示例中的屏幕截图进行详细说明，并进行了轻微的增强。|104642|​|104643|📷|atomic|104644|104645|entityMap|0|IMAGE|mutability|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/b24c2b37263d36c86be59c373e3d852b.png|imageAlt^0|6|6|L|A|0|0|0|0|0|0|0|0|1|0|0|0^^$0|@$1|2|3|4|5|6|7|17|8|@$9|18|A|19|B|C]|$9|1A|A|1B|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|1C|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|1D|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|1E|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|1F|8|@]|D|@]|E|$K|L]]|$1|Q|3|R|5|6|7|1G|8|@]|D|@]|E|$]]|$1|S|3|T|5|6|7|1H|8|@]|D|@]|E|$]]|$1|U|3|V|5|W|7|1I|8|@]|D|@$9|1J|A|1K|1|1L]]|E|$]]|$1|X|3|T|5|6|7|1M|8|@]|D|@]|E|$]]|$1|Y|3|-4|5|6|7|1N|8|@]|D|@]|E|$]]]|Z|$10|$5|11|12|13|E|$14|15|16|-4]]]]

One way to do this by updating the <code>app.locals</code> variable for that app in <code>app.js</code>

Set via following

<pre><code>var app = express();
app.locals.appName = "DRC on FHIR";
</code></pre>

Get / Access

<pre><code>app.listen(3000, function () {
 console.log('[' + app.locals.appName + '] =&gt; app listening on port 3001!');
});
</code></pre>

Elaborating with a screenshot from @RamRovi example with slight enhancement. 

<a href="https://i.stack.imgur.com/5XBVK.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/5XBVK.png" alt="enter image description here"></a>

blocks|key|104675|text|您也可以使用"global“|type|unstyled|depth|inlineStyleRanges|entityRanges|data|104676|示例：|104677|像这样声明：|104678|++app.use(function(req,res,next){
++++++global.site_url+=+req.headers.host;+++//+hostname+=+'localhost:8080'
++++++next();
+++});|code-block|syntax|javascript|104679|使用方法如下:在任何视图或ejs文件中<%25+console.log(site_url)；%25>|104680|在js文件中console.log(site_url)；|104681|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|S|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|T|8|@]|9|@]|A|$I|J]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

you can also use "global" 

Example:

declare like this :

<pre><code> app.use(function(req,res,next){
 global.site_url = req.headers.host; // hostname = 'localhost:8080'
 next();
 });
</code></pre>

Use like this:
 in any views or ejs file
 &lt;% 
 console.log(site_url);
 %> 

in js files
 console.log(site_url);

blocks|key|321739|text|为了避免被污染的全局作用域，我所做的就是创建一个可以包含在任何地方的脚本。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|321740|//+my-script.js
const+ActionsOverTime+=+require('@bigteam/node-aot').ActionsOverTime;
const+config+=+require('../../config/config').actionsOverTime;
let+aotInstance;

(function+()+{
++if+(!aotInstance)+{
++++console.log('Create+new+aot+instance');
++++aotInstance+=+ActionsOverTime.createActionOverTimeEmitter(config);
++}
})();

exports+=+aotInstance;|code-block|syntax|javascript|321741|这样做只会创建一次新实例，并在包含该文件的所有位置共享该实例。我不确定是因为变量被缓存了，还是因为应用程序的内部引用机制(可能包括缓存)。任何关于node如何解决这个问题的评论都会很棒。|321742|也许还可以阅读这篇文章来了解require的工作原理：http://fredkschott.com/post/2014/06/require-and-the-module-system/|offset|length|321743|entityMap|0|LINK|mutability|MUTABLE|url|http://fredkschott.com/post/2014/06/require-and-the-module-system/^0|0|0|0|R|1U|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|X|8|@]|9|@$K|Y|L|Z|1|10]]|A|$]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

What I do in order to avoid having a polluted global scope is to create a script that I can include anywhere.

<pre><code>// my-script.js
const ActionsOverTime = require('@bigteam/node-aot').ActionsOverTime;
const config = require('../../config/config').actionsOverTime;
let aotInstance;

(function () {
 if (!aotInstance) {
 console.log('Create new aot instance');
 aotInstance = ActionsOverTime.createActionOverTimeEmitter(config);
 }
})();

exports = aotInstance;
</code></pre>

Doing this will only create a new instance once and share that everywhere where the file is included. I am not sure if it is because the variable is cached or of it because of an internal reference mechanism for the application (that might include caching). Any comments on how node resolves this would be great.

Maybe also read this to get the gist on how require works:
<a href="http://fredkschott.com/post/2014/06/require-and-the-module-system/" rel="nofollow noreferrer">http://fredkschott.com/post/2014/06/require-and-the-module-system/</a>

Ok, so I have built a blog using <a href="http://jekyllrb.com/">Jekyll</a> and you can define variables in a file <code>_config.yml</code> which are accessible in all of the templates/layouts. I am currently using <a href="http://nodejs.org">Node.JS</a> / <a href="http://expressjs.com">Express</a> with <a href="http://embeddedjs.com/">EJS</a> templates and <a href="https://github.com/RandomEtc/ejs-locals">ejs-locals</a> (for partials/layouts. I am looking to do something similar to the global variables like <code>site.title</code> that are found in <code>_config.yml</code> if anyone is familiar with Jekyll. I have variables like the site's title, (rather than page title), author/company name, which stay the same on all of my pages. 

Here is an example of what I am currently doing.:

<pre><code>exports.index = function(req, res){
 res.render('index', { 
 siteTitle: 'My Website Title',
 pageTitle: 'The Root Splash Page',
 author: 'Cory Gross',
 description: 'My app description',
 indexSpecificData: someData
 });
};

exports.home = function (req, res) {
 res.render('home', {
 siteTitle: 'My Website Title',
 pageTitle: 'The Home Page',
 author: 'Cory Gross',
 description: 'My app description',
 homeSpecificData: someOtherData
 });
};
</code></pre>

I would like to be able to define variables like my site's title, description, author, etc in one place and have them accessible in my layouts/templates through EJS without having to pass them as options to each call to <code>res.render</code>. Is there a way to do this and still allow me to pass in other variables specific to each page?

How to create global variables accessible in all views using Express / Node.JS?

中间件

好了，我已经使用构建了一个博客，您可以在文件_config.yml中定义变量，这些变量可以在所有模板/布局中访问。我目前正在使用带有模板和的 /  (用于部分/布局。我希望做一些类似于在_config.yml中找到的全局变量，如site.title，如果有人熟悉Jekyll。我有一些变量，比如网站的标题，(而不是页面标...

问如何使用Express / Node.JS创建可在所有视图中访问的全局变量？
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