This is my first project with all these technologies, I typically do Angular, but I am working for a charity ( and keen to learn node ). This is day three.
During a login, this is the method called:
schema.statics.authenticateAndLoad = function(req, res, next) {
var userId = req.body.email;
res.locals.userId = userId;
This is supposed to store the value so it doesn't need to be reentered. If login fails, it does this:
return next('Login failed. Please enter your details and try again.');
Then in my Jade template:
if(locals.userId)
p Welcome to #{userId}
else
p Welcome
The actual template has code to try to do what I want:
input(type='text', name='email', id="inputEmail", placeholder="Email", value="#{body.email || ''}")
But this does not work.
So, I THINK this means my setting a value in the result is lost when I call 'next', but, because it's also passing in this error object to show on the screen, I'm not sure how I would go about making sure this error shows AND make the value pass through . Right now, my text just says 'welcome' and never 'welcome to xx', this is test code, I'm just proving the value is not being passed through.
My question is, what's the correct way to pass the value through to my template, and ALSO trigger the error message that is being shown.
The code, when I step in to it, goes deep in to Express and checks for errors there.
Hi it is good to see some developers doing charity work.
Typically what you would use is something like this assuming this is a piece of middleware
schema.statics.authenticateAndLoad = function(req, res, next) {
var userId = req.body.email;
res.locals.userId = userId;
loginFunction(userdetails,function(error,result){
//if there is an error you need to render the page or do a redirect to the
//login page
if(error){
var msg = 'Login failed. Please enter your details and try again.'
return res.render('login',{userId: userId,error: msg})
//this renders the login page and passes req.body.email to the page as userID and the msg as error
}
if(result){
//if this is correct you return next() as you are saying
//you may go through
return next()
}
}
}
then on your jade to display the error you use and userID
p #{userID}
p #{error}
So to answer your question the correct way to send the value to jade you pass it in using this and pass the error in as a variable.
return res.render(template_name,{userId: req.body.email,error: msg})
I hope this helps you out
Related
My code is
main.post('/userlist', function(req, res, next) {
// where did you get this?
// var db = req.db;
var query = connection.query("SELECT name,zaman,giriscikis FROM giriscikis where date_format(zaman,'%Y-%m-%d') between ? and ?", [req.body.bas, req.body.bitis], function(err, result) {
if (err) throw err;
console.log(result);
res.send(httpResponse(result));
return res.redirect('/zamansorgu');
//console.log(req.body.bas)
//console.log(req.body.bitis)
});
});
I want to fecth data from database and redirect to same page in the code(zamansorgu.html)
But I get an error
Cannot set headers after they are sent to the client
How can I solve this problem
thank you for your helps
You are attempting to send back JSON data and redirect to a different page. That's not possible. Each endpoint request can have one response, not more. You can either send back the data, or redirect. That's because redirecting really does send back data too (the html of the new target page).
Think about it from the caller's point of view. If it did allow this how would it work? If someone uses this link from a browser should the browser show the JSON data you returned, or should it take the user to the new page?
The error is saying "hey, I already sent back data. I can't redirect now because we are already down the path of returning some JSON".
If you want to use the data to format the output that can be done, or if you want to redirect to a new location and pass the data in the url, that's also possible. Consider code like this:
main.post('/userlist', function(req, res, next) {
// var db = req.db;
var query = connection.query("SELECT name,zaman,giriscikis FROM giriscikis where date_format(zaman,'%Y-%m-%d') between ? and ?", [req.body.bas, req.body.bitis], function(err, result) {
if (err) return next(err);
if (result.urlparam) {
// this builds a new url using the query value
const nextUrl = `/zamansorgu?param=${result.urlparam}`;
return res.redirect(nextUrl);
}
else {
// this builds html here
const html = `<html><body><h1>${result.title}</h1></body></html>`;
return res.send(html);
}
});
});
I also ran into this, in my case it was quite a deceptive little bug. A node-inspector session helped me pinpoint the problem quickly however. The problem in my case was pretty bone-headed, the res.end call in the sample below is the offending line.
res.writeHead(200, {"Content-Type": "application/json"});
res.end(JSON.stringify(someObject));
someObject did not exist after a refactor and that was causing a ReferenceError to get thrown. There is a try-catch in Router.prototype._dispatch that is catching the ReferenceError and passing it into next
res.status(301).redirect(`/zamansorgu?name=${"John"}&email=${"john#email.com"}`)
So, this is something I explored but it will be dependent on the structure of your application. You could always pull the data out using query params and hydrate your application.
I've currently written middleware to verify an ID exists in an external services (Salesforce). I initially wrote it when it was a single use app, but now I'm trying to make it work with different routes, so I want it to be fairly generic.
I don't even know if middleware is the right way to go, or if I should just call the function before saving the specific form.
I've got a form where someone puts in some information about a project, and the salesforce ID. For background, the salesforce ID is actually an auto-increment number, and I need to convert that to the actual salesforce system ID before I use jsForce to create a new object linked to that ID.
My route looks like this:
router.post('/invoice/add', ensureLoggedIn, invoiceController.validateInvoice, catchErrors(sfdc.validateSFID), catchErrors(invoiceController.saveInvoice))
So, I've got a middleware that does this:
exports.validateSFID = async(req, res, next) => {
const salesforceProjectNumber = req.body.SF_Opportunity
const sfResult = await conn.search(`FIND ... long query`, (err, result) => {
if (err || result.searchRecords.length !== 1) {
req.flash('error', 'Unable to find a Salesforce Job with that ID number.')
console.error(`ERROR: ${req.user.displayName} errored when looking up job number ${salesforceProjectNumber}.`)
return result
}
})
if (sfResult.searchRecords.length > 0) {
req.body.salesforce_Opportunity_id = sfResult.searchRecords[0].Id //Create a generic variable to hold the salesforce opportunity so it works regardless of the custom object name
res.locals.Opportunity_Clean_Name = sfResult.searchRecords[0].Name
}
next()
}
The query rarely throws an error, but in this case, an error is basically returning !1 records.
When that happens, I want to flash a message on the screen saying the ID wasn't found, but keep the form filled in.
When an ID is found, I want to proceed to save it and NOT display the form fields anymore.
This middleware needs to work regardless of the form I'm using, I want to be able to pipe in the middleware from any form that might require a user to enter a salesforce job as a field.
Any thoughts on how best to handle it all?
You can use your middleware by using app.use() function
app.use((req, res, next) => {
// Every time a request has made, this middleware will fire
console.log('Howdy');
})
I'm putting together a basic project admin/management site and decided to finally learn to use node/express/monk/jade/redis, the works. Everything was going fine but I've run into a problem trying to get data passed between the route handler in index.js and the jade template file.
in index.js
exports.auth = function( db )
{
return function( req, res )
{
var userName = req.body.username,
userPassword = req.body.password,
authenticated = false;
// check credentials code
// ...
if (authenticated)
{
// set some session stuff
res.redirect( "home" ); // good to go
}
else
{
res.locals.err = "Authentication error";
res.redirect( "login" ); // show err on login page
}
}
}
in login.jade
- if (typeof( locals.err ) !== 'undefined' ) {
p.errormsg #{ locals.err }
- }
Iterating over locals in the jade template it doesn't show an entry for err. Does res.redirect() wipe out the err entry I made in index.js? Or am I actually dealing with two different objects (res.locals in index.js and locals in the jade template)?
My original approach was to use res.render( "login", { "err" : "Authentication err" } ) instead of redirecting, but I cannot figure out how to get the browser to show /login and not /auth when the error happens. I tried
res.location( "login" );
res.render( "login", { "err" : "Authentication err" });
but the browser still shows /auth.
The only other approach I found was using session data. The session object is available in both places and I can set/read the information from it as needed. The solution is inelegant though since the session info persists through reloads of the login page so the browser just keeps showing the error message for the original attempt rather than reloading/rendering a clean login page.
Any help is appreciated, and thanks in advance!
Yes - the redirect is returning a redirect to the client, which makes a separate request from the client. Your prior res.locals.err is long gone. You may want to read the doc on res.redirect().
Session data would be a sensible way to handle this unless you are a hardcore about statelessness. I am not sure why you find it inelegant. Why don't you reset that element of the session data after you render the next page?
There are different ways you can handle your issue about what the location bar shows if you search around for some javascript. Feels like a bit of kludge though.
Personally, I just have a /login path - called via GET it displays the login page, called via POST it authenticates, redirects if successful, or renders the login template with the error if the login is bad. No session data necessary.
I'm using Node/Express and Jade to build and App.
I have a POST route that sanitize and validate form input and then save this to a MongoDB.
If this form input is'nt validated, the route will throw and error and the error handler will re-render this same page...
And here come the problem. In this re-render and want the form values be pre written and ready to be corrected by the user... I don't want a clean form where the user has to re-write everything.
I have tried to submit the req.body (sanitized) data to the re-rendered page, which works.
But if try to use this data in my Jade view, Node will output and error when this req.body data is not defined... Like when you enter this page for the first time, and have'nt entered any wrong inputs yet.
How do i solve this in a good way?
edit - Without a code sample I'm not sure if my example is more or less than you need.
If you render the form template immediately within the the form's POST request handler, you probably don't need to involve req.session. Just save the appropriate locals and render your template.
If you must redirect or otherwise need to have the values available across multiple requests, you can save them in req.session as shown below.
Either way make sure your Jade template handles all cases; in my example I test if(locals.savedValues) to decide whether to write defaults or saved values into the form.
Finally if the error is not jade related please paste that error.
Use req.session to save the values. Set up a locals variable to represent the saved values or null before you render the form.
app.get('/form', function(req, res){
res.locals.savedValues = req.session.savedValues || null;
res.locals.savedErr = req.session.savedErr || null;
res.render('form');
});
app.post('/form', function(req, res){
var values = {
name: req.body.name,
email: req.body.email,
};
validateForm(values, function(err, processed){
if(err){
req.session.savedValues = processed;
req.session.savedErr = err;
// req.session.savedValues = values, if you dont want to propose changes
res.redirect('back');
} else {
delete req.session.savedValues;
delete req.session.savedErr;
res.redirect('/success');
};
});
});
In your jade template, handle both cases:
if(locals.savedErr)
span.error=locals.savedErr
form(action='form', method='post')
if(locals.savedValues)
input#name(type='text')=locals.savedValues.name
input#email(type='text')=locals.savedValues.email
else
input#name(type='text')
input#email(type='text')
I am testing with a very simple application in node.js where I create and save an application. I show the post form with the newPost function and I receive the post with the data in the savePost method. In the latter one I do a validation (with iform module) and I want to go show again the same page as before but filling the form with the data sent by the user and also with the errors found.
I have a similar code like this one. In it I render the same jade page if I find any error. It works though I want to apply the pattern redirect and get there as I don't want to send again the post request when the user presses F5.
So, how is the usual way to make a post redirect and get from the post method passing them all the parameters I have received adding the errors? Is there any module which can help to do so?
var prepareObject = function(req, res){
var errors = {};
if('iform' in req){
errors = req.iform.errors;
}
return {title: 'Nuevo Post', body:req.body, errors: errors};
};
// mapped as /newPost (type GET)
exports.newPost = function(req, res){
//show form to create post
res.render('newPost', prepareObject(req, res));
}
// mapped as /savePost (type POST)
exports.savePost = function(req, res){
if(req.iform.errors) {
//there are errors: show form again to correct errors
res.render('newPost', prepareObject(req, res));
}else{
//no errors: show posts
res.redirect('/posts');
}
}
You can redirect to GET "/newPost" instead of rendering the "newPost" template.
To have autocomplete working, you may either add the data to the redirect query (faster) and render it, or add the data to the session (don't forget to delete it after rendering), but the later option requires a session store.