Calling React setState from inside a child function - meteor

I have a React component that has a function which calls a Meteor login method inside one of it's functions. If login succeeds, I need to to adjust the components state, but that is failing. I am guessing I need another bind(this) or something somewhere but am not sure where. Or maybe I need to extract the setState out into another function and call it from this one. What the typical/best approach to something like this?
-SomeComponent.jsx
handleSubmitLogin(e) {
e.preventDefault();
let email="my#email.com";
let password='mypassword';
Meteor.loginWithPassword(email, password, function(error) {
if (Meteor.user()) {
this.setState({ //<- ***THIS ERRORS WITH 'Cannot read property setState of undefined'***
showLogin: false,
});
} else {
console.log("There was an error logging in: "
+ error.reason);
}
})
}
TIA!

It looks like you're using ES6, so you can use arrow functions:
Meteor.loginWithPassword(email, password, (error) => { ... });
Arrow functions effectively inherit this from their surrounding scope, so this will refer to the right thing in your function.
If you're stuck on ES5, you can simply bind the this context:
Meteor.loginWithPassword(email, password, function (error) { ... }.bind(this));

Related

Meteor method + check() + audit-argument-checks + async/await causes exception

I’m using meteor with check() and audit-check-arguments package.
When I use a meteor method using async/await and pass a parameter, even though I use check() to validate the function parametrs, the audit package still throws an exception indicating that not all input parameters have been checked. If I remove the async/await implementation, the package does not crib. What am I missing?
Example:
Meteor.methods({
test: async function(param1){
check(param1, String);
...
await ....
}
});
Throws an exception:
=> Client modified -- refreshing
I20200513-10:43:27.978(5.5)? Exception while invoking method 'test' Error: Did not check() all arguments during call to 'test'
I20200513-10:43:27.979(5.5)? at ArgumentChecker.throwUnlessAllArgumentsHaveBeenChecked (packages/check/match.js:515:13)
Whereas this traditional meteor method does not throw any exceptions
Meteor.methods({
test: function(param1){
check(param1, String);
...
}
});
I know for sure that I am passing exactly one parameter.
It looks like audit-argument-checks only works for synchronous functions.
I don't have this issue because we use mdg:validated-method, which uses requires you to specify an argument validator for each method.
It shuts up the argument checker by wrapping the method function with this:
// Silence audit-argument-checks since arguments are always checked when using this package
check(args, Match.Any);
The simplest solution I can think of, is to separate the check from the async function. You could use a wrapper function to do this:
function checkAndRun(check, run) {
return function(...args) {
check.apply(this, args);
return run.apply(this, args);
}
}
Meteor.methods({
'example': checkAndRun(
function(exampleID){
check(exampleID, String);
},
async function(exampleID) {
const result = await doSomethingAsync(exampleID);
SomeDB.update({ _id: exampleID }, { $set: { someKey: result.value } });
return result.status;
}
}
});
or you could even do it inline with an async IIFE:
Meteor.methods({
example(exampleID) {
check(exampleID, String);
return (async () => {
const result = await doSomethingAsync(exampleID);
SomeDB.update({ _id: exampleID }, { $set: { someKey: result.value } });
return result.status;
})()
}
});
Which, come to think of it, is much simpler than the simplest solution I could think of at first 🙃
You just want to separate the sync check from the async method body somehow
In case you're curious, let diving through the source to see where it's called. When the method is called (in ddp-server/livedata-server), we end up here, a sync method call for the first reference of audit-argument-checks:
https://github.com/meteor/meteor/blob/master/packages/ddp-server/livedata_server.js#L1767-L1770
Which takes us into check/Match for another sync call here: https://github.com/meteor/meteor/blob/71f67d9dbac34aba34ceef733b2b51c2bd44b665/packages/check/match.js#L114-L123
Which uses the strange Meteor.EnvironmentVariable construct, which under the hood has another sync call: https://github.com/meteor/meteor/blob/master/packages/meteor/dynamics_nodejs.js#L57

Error: Meteor code must always run within a Fiber

I am using stripe for payments in my app, I want to create a receipt document in my own database after a succesful transaction
My code:
Meteor.methods({
makePurchase: function(tabId, token) {
check(tabId, String);
tab = Tabs.findOne(tabId);
Stripe.charges.create({
amount: tab.price,
currency: "USD",
card: token.id
}, function (error, result) {
console.log(result);
if (error) {
console.log('makePurchaseError: ' + error);
return error;
}
Purchases.insert({
sellerId: tab.userId,
tabId: tab._id,
price: tab.price
}, function(error, result) {
if (error) {
console.log('InsertionError: ' + error);
return error;
}
});
});
}
});
However this code returns an error:
Error: Meteor code must always run within a Fiber. Try wrapping callbacks that you pass to non-Meteor libraries with Meteor.bindEnvironment.
I am not familiar with Fibers, any idea as to why this is?
The problem here is that the callback function which you pass to Stripe.charges.create is called asynchronously (of course), so it's happening outside the current Meteor's Fiber.
One way to fix that is to create your own Fiber, but the easiest thing you can do is to wrap the callback with Meteor.bindEnvironment, so basically
Stripe.charges.create({
// ...
}, Meteor.bindEnvironment(function (error, result) {
// ...
}));
Edit
As suggested in the other answer, another and probably better pattern to follow here is using Meteor.wrapAsync helper method (see docs), which basically allows you to turn any asynchronous method into a function that is fiber aware and can be used synchronously.
In your specific case an equivalent solution would be to write:
let result;
try {
result = Meteor.wrapAsync(Stripe.charges.create, Stripe.charges)({ /* ... */ });
} catch(error) {
// ...
}
Please note the second argument passed to Meteor.wrapAsync. It is there to make sure that the original Stripe.charges.create will receive the proper this context, just in case it's needed.
You might want to take a look at the docs for http://docs.meteor.com/#/full/meteor_wrapasync.

wrapAsync + method + session

i'm having issues with wrapAsync + method + sessions.
How do I implement the WrapAsync correctly?
I want, in a template to know if the user has at least one item created by him. And then define whether or not he can create another item.
Now i'm getting this error:
W20141013-15:04:43.237(-3)? (STDERR) Error: Can't wait without a fiber
But, I could not find Fiber at Documentation. And for implementing this, is it really necessary?
 
On the client side I want something like:
//pagina.js
Template.pagina.helpers{
userHasItem: return Session.get('userHasItem');
}
//pagina.js
Meteor.call('userHasItem', Meteor.userId(), function (error,result) {
Session.set('userHasItem', result);
});
//at server side:
if(Meteor.isServer){
Meteor.startup(function () {
var userHasItemAsync = function (userId) {
setTimeout(function () {
if (Items.findOne({'userId': userId})) {
return true;
} else {
return false;
}
}, 4000);
};
Meteor.methods({
userHasItem: function(userId) {
var userHasItemSync = Meteor.wrapAsync(userHasItemAsync),
result;
try {
userHasItemSync(userId);
console.log(result);
return result;
}catch (e) {
console.log('erreur', e.message);
throw new Meteor.Error(500, e);
}
},
}
});
}
Can't get your error to reproduce based on the existing code.
Still, userHasItemAsync is not available because you've defined it locally in the Meteor.startup function. But the error you should get in this case is userHasItemAsync is undefined.
Also the code you've entered here has multiple errors (i guess you typed it in not copy / pasted from your project): template instead of Template, Template it's defined outside of isClient (probably it's in a file available for the client) etc. Because of that it's hard to reproduce your exact case.
There is no need to call a server method to see if the item exists (assuming you have set up the proper publications/subscriptions), nor any need to call wrapAsync. In fact, what you want to achieve doesn't even require a session. All of the code can be ultimately distilled to this:
Template.pagina.helpers{
userHasItem: return Items.find({ userId: Meteor.userId() }).count() > 0;
}
The cursor returned by Items.find is reactive in itself, so there is no need for using a Session.

Meteor template updates before result of Meteor.users.update

I'm trying to figure out how to prevent a template from updating until Meteor.users.update() finishes.
First I'm trying to make sense of the documentation and the use of an optional callback argument in order to sort out what is happening.
Here is what I have:
Meteor.users.update(Meteor.userId(),
{$set:{'profile.reviewList': []}},
[],
function(err, result){
if (err){
console.log('oh no!');
} else {
console.log('Result achieved: '+this.profile.reviewList);
}
});
Currently the console.log('Result achieved: '+this.profile.reviewList); always returns something like ...TypeError: Cannot read property 'reviewList' of undefined... the first time though which tells me its firing before the result comes back.
I'm sure I'm not implementing the callback properly, but I was attempting to model this answer: How do you ensure an update has finished in meteor before running a find?
I'd really just like to delay the re-rendering of the associated template until the property gets created.
Any help will be greatly appreciated.
You assume that scope (this) in callback function return user object, which is wrong.
If you want to get user object in that callback simply query it there:
var user = Meteor.users.find(Meteor.userId()).fetch()
Another thing, you passed empty array as 2nd argument which is not needed.
Meteor.users.update(
Meteor.userId(),
{
$set: {
'profile.reviewList': 'testData'
}
},
function(err, result) {
if (err) {
console.log('oh no!');
} else {
var user = Meteor.users.find(Meteor.userId()).fetch();
console.log('Result achieved: ' , user && user.profile && user.profile.reviewList);
}
}
);

How do I ensure that nested async code will test correctly using Mocha?

I am working with Mocha and am trying to test an API that I am in the process of building.
I am having trouble understanding where to place the done() function.
If I place it where it is now, it doesn't execute the callback function of User.findOne().
If I place the done at the bottom of the callback function of User.findOne(), then it creates a timeout.
I am relatively new to async and this done function, so can someone help explain why these two cases happen, and how to fix the code so that it will test correctly in Mocha?
describe('POST /signup', function() {
before(checkServerIsRunning); // Need to implement
it('create a new user if username is unique', function(done) {
httpReq({
method : 'POST',
url : url + '/signup',
json : true,
body : JSON.stringify({
username : 'test',
first : 'first',
last : 'last' })
},
function (err, res, body) {
if (err) {
done(err);
}
else {
res.statusCode.should.be.equal(201);
User.findOne( { username: 'test' }, function(err, user) {
user.should.have.property('username', 'testy');
user.should.have.property('firstName', 'first');
user.should.have.property('lastName', 'last');
usersToRemove.push(user);
});
done();
}
}
);
});
});
You should place done() inside the called to findOne.
If you're finding that it times out then either findOne is never calling its callback (which is an error!) or it's taking too long to execute.
In this case you could up the timeout by sticking something like this.timeout(5000) at the beginning of the test (which increases the timeout to 5 seconds).
In general you wouldn't usually want tests that slow though, so maybe try and figure out why it takes so long.

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