express + ejs login widget - node.js

I am trying to make easy widget for buttons login/logout.
laout.ejs
<% include ../shared/login_logout %>
login_logout.ejs
<% if ( !common.IsDefined(membershipHelper.GetCurrentUser(request , response)) ) { %>
<li class="pull-right">Login</li>
<% } else { %>
<li class="pull-right">Log Out</li>
<% } %>
membershipHelper.GetCurrentUser - this method checks request session for user_id and if it finds it returns user if it is found in db(mongoDB) else it returns null. As user is returned in callback function of User.findById ejs file receives "undefined" always. I thought to put this GetCurrentUser in the middleware but it look like I can't set null or undefined to locals variable
What can be solution for this problem?

Related

How do i make the ejs variable work that i send from nodejs?

I am tring to get a variable that i send from nodejs to ejs to work. But for some reason it wont, i cant figure out why.
This is the index.js:
var newOne = "Yes"
router.get('/main', ensureAuthenticated, (req, res) =>
res.render('main', {
user: req.user,
newOneInView : newOne
})
)
And this is in the main.ejs file:
<%if (newOneInView == "Yes") { %>
document.getElementById("avatar").src = "/static/images/Apocaliptic1.png";
<% } %>
So what i am trying to achieve is that variable will be seen from the nodejs at the main.ejs page but some reason it wont change the image SRC. What am i doing wrong here?
In your template you need to make sure that you place the code for changing the src attribute in a script that is placed after the element (alternatively you can use a listener for the content to be loaded), e.g:
<body>
<img id="avatar" src="/some-other-path"/>
<script>
<% if (newOneInView === "Yes") { %>
document.getElementById("avatar").src = "/static/images/Apocaliptic1.png";
<% } %>
</script>
</body>

In Nodejs, how can i check params in Ejs render

I want to display another view if there is :id in Semantic URL
app.get(['/topic', '/topic/:id'], function(req, res){
id = req.params.id
if(id){
res.render('view',{topics:rows, topic:row[0]}
}else{
res.render('view', {topics:rows}
}
}
and view.ejs
for(var i = 0; i < topics.length; i++){
<li><%= topics[0].title%></li>
}
<% if(topic) {%>
<%= topic.description %>
<%} else {%>
<h1>Welcome</h1>
<% } %>
it did works correctly when i connect to localhost:3000/topic/1
but when i connect to localhost:3000/topic
console said topic is not defined
what is the problem?
When i use
res.render('views', {topics:rows, topic:''}
it did works correctly
Do i have to use like this?
In view.ejs it is best to check the if condition as follows. Not only in ejs but in entire javascript world
<% if(typeof topic !== 'undefined') {%>
<%= topic.description %>
<%} else {%>
<h1>Welcome</h1>
<% } %>
And you can use also use res.render('views', {topics:rows, topic:''}

Conditional operators in ejs

This might sound really easy. There is a very similar
answer but somehow my code is behaving abruptly and driving me crazy. I have spent last 4-5 hours on this. Any help would be great.
I am building a Socket.IO chat app using Node + Express + Passport. I want to compare the userId of the current user with that of other users connected. I want to show him all users except himself to chat with in Socket.IO.
Read comments on code for clarity :
users.js
app.get('/users', function (req, res) {
var connectedUsers = require('../app').chatUsers; // => This is an array of all logged in user and I am getting this all correctly.
if (req.isAuthenticated()) {
res.render('users', {
currentUser: req.user,
users: connectedUsers,
title: 'OnLineUsers'
});
}
});
users.ejs
<h3>CurrentUser : <%- currentUser.id %></h3> // => This Prints like **abcdefg**
<% for(var i = 0;i < users.length ; i++){ %>
<h3>UserID: <%- users[i].id %></h3> // => This also prints the same **abcdefg** if only one user is connected.
<% if( currentUser.id !== users[i].id){ %> // => But this Conditional Operator does not works and show the current user himself.
<ul>
<li>
<h3> <%= users[i].name %></h3>
<a href="/socket" id="chatRoomUrl">
<button type="submit" class="btn-success">Chat</button>
</a>
</li>
</ul>
<% } %>
<% } %>
Thanks in advance. If there is any silly mistake on my part, please excuse me for wasting your time.
Your code is fine. Maybe there is space in two property. Try :
currentUser.id.trim() !== users[i].id.trim()
Change your following line, notice the change:
<h3> <%= users[i].name %></h3>
to this:
<h3> <%- users[i].name %></h3>

Update EJS Layout with Session

My ejs layout provides the current user's username on the main menu through sessions
<a href="">
<% if (typeof currentUser === 'undefined'){%>
<% } else { %>
<a style="text-decoration:none;" href="/users/logout">Logout</a>
<% } %>
</a>
Now when I destroy the session and redirect to the main page, the currentUser's infomation is still showing, although logging currentuser returns undefined. Is there a way to force the layout to update itself to show current information?

Unable to display flash message in view with ejs template

I am a newbie in NodeJS. I have a problem that I am unable to show flash message in my view.
Here is my Controller,
index : function(req, res){
res.locals.flash = _.clone(req.session.flash);
res.locals.layout = false;
res.view('login');
},
login : function(req, res){
....
if(!admin){
req.session.flash = {
err : 'User is not found.' // My flash message
}
res.locals.layout = false;
res.redirect('login');
return;
}
.....
}
Here is my view,
<% if(flash && flash.err) { %>
<div class="alert alert-danger">
<% JSON.stringify(flash.err) %>
</div>
<% } %>
When login is false, it show only an empty alert box.
And I have a second problem. When I refresh page, The alert box isn't disappeared.
Could someone help me please.
Thanks a lot.
The alert box keeps on appearing because the req.session.flash object persists the session, so you need to null that out once it's used, or you can just simply use req.flash(), which does that for you. So change your index method to something like this:
index: function(req, res) {
// req.flash() returns the contents of req.session.flash and flushes it
// so it doesn't appear on next page load. No need to clone.
res.locals.flash = req.flash();
res.locals.layout = false;
res.view('login');
},
Now, onto the second problem. The error messages aren't appearing because you aren't using the proper EJS syntax to output escaped values into the view. All you need to do is change your code to this:
<% if(flash && flash.err) { %>
<div class="alert alert-danger">
// Change <% to <%=
<%= flash.err %>
</div>
<% } %>
No need to JSON.stringify, unless you like the quotes. Notice that I changed the <% to <%=, which in EJS means "escape this and output it". It's not template HTML or anything like that, so it's okay to escape it anyway.

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