Ember CLI Inject Meta
Inject content into a meta tag which is defined as a module on runtime. This allows you to do operations such as read a cookie to set user data, make async calls to server to get permissions, get/set feature flags, so on and so forth all before your application loads.
Setup
In this example, we will create our user config that will be located in <APP_NAMESPACE>/config/user.js
. In your express server, you will have to define the middleware.
// server/index.js
var injectMeta = require('ember-cli-inject-meta');
app.use(injectMeta(function(req) {
return {
path: 'config/user',
content: {
username: 'offirgolan',
isAdmin: true
}
};
}))
This will add the following meta tag in your index.html
<meta name="app/config/user" data-module="true" content="%7B%22username%22%3A%22offirgolan%22%2C%22isAdmin%22%3Atrue%7D">
// app/routes/index.js
import Ember from 'ember';
import User from '../config/user';
export default Ember.Route.extend({
redirect() {
if(user.isAdmin) {
this.transitionToRoute('admin.index');
}
}
})
Possible Inputs
The injectMeta
function is passed a callback function that is given req
. You must return either an array of objects / promises, or a single object / promise. Each meta module object should have:
path
(String): The path used to define your modules. (i.econfg/user
)content
(Object): The content your module will contain. This will be stringified and escaped before injecting it into the meta tag.
Examples
Single Meta Tag
injectMeta(function(req) {
return {
path: 'config/user',
content: { username: 'offirgolan' }
};
});
Multiple Meta Tags
injectMeta(function(req) {
return [{
path: 'config/user',
content: { username: 'offirgolan' }
},{
path: 'config/api',
content: { endpoint: 'api/v2' }
}]
})
Multiple Meta Tags with Promises
injectMeta(function(req) {
var userConfig = getUserConfig(req).then(function(result) {
return {
path: 'config/user',
content: result
}
});
var apiConfig = getAPIConfig(req).then(function(result) {
return {
path: 'config/api',
content: result
}
});
return [ userConfig, apiConfig ];
})