Im trying to get the details of a token transaction on near.
Details like the token amount that was sent.
The JSON RPC endpoints only returns details related to the amount of NEAR involved in the transaction.
Some of the tokens(like token.sweat) emit a log that contains the token amount involved in the transaction, but this is not consistent across all tokens on Near.
Is there a standard way of getting this?
I'd imagine there is, because explorers on near are able to get these details too.
Thanks.
There is a standard for event logs in NEAR.
Here is an example log of the ft_transfer event for Fungible Tokens (NEP141) on NEAR.
FtTransfer {
old_owner_id: sender_id,
new_owner_id: receiver_id,
amount: &U128(amount),
memo: memo.as_deref(),
}
.emit();
Here is an example output.
Log [dev-1671032805857-80440743716599]: EVENT_JSON:{"standard":"nep141","version":"1.0.0","event":"ft_transfer","data":[{"old_owner_id":"dev-1671032805857-80440743716599","new_owner_id":"new_owner_id.testnet","amount":"10000000000000000000","memo":"Your memo here"}]}
You can parse the log in the event JSON to get the params you want.
Related
Considering that
get_esdt_token_data(address: &ManagedAddress, token_id: &TokenIdentifier, nonce: u64) -> EsdtTokenData<Self::Api>
always returns an EsdtTokenData rather than an option. What will this object look like if the address does not own the specified token?
The execution will fail as the VM will not return anything to the smart contract if it doesn't find the token.
The typical usage for this function is to get the data for the payment tokens the smart contract receives from the caller. If you're trying to use it freely, you might get into this situation, so this type of "free" usage is not really advised.
I have a HTML form, which I submit via http post.
There are two cases:
Case 1: The data is valid and data on the server will be updated accordingly
Case 2: The data is invalid and the http response contains an error message for the user.
Which http status codes should be used for each case?
I use htmx to submit the form. This means I don't need to use the POST/Redirect/GET pattern.
This question is not about JSON-APIs.
The complete list of HTTP response codes published by the Mozilla Foundation is pretty comprehensive and easy-to-read, so I'd recommend always consulting it as a guide. For the generic use-cases mentioned by you, there are a couple of different codes you can return - depending on what happens with the data on the server, and what you want to happen in the user's browser.
CASE 1: data is valid, data on server is updated
Base on your short description, the different status codes that might be applicable are:
200 (OK): you are updating an existing record on your own server - eg., the user is submitting a form which updates their existing contact information on your website - and information was received, and the record updated successfully. The response would usually contain a copy of the updated record.
201 (Created): you are not updating an existing record, but rather, creating a new record on your server - eg., your user is adding a new phone number to their contact details, which is saved in your database as a separate 'phone' record. The response should contain a copy of the newly created record.
205 (Reset Content): the same as 200, but implies that the browser view needs to be refreshed. This is useful when the record that is being updated has values that are dynamically calculated by the server, and which might change automatically depending on the values you're submitting. For example, if you have a user adding extra information to their online profile, which might grant them special status, badges and privileges on the website. This means, that if the user is viewing their profile information, that information will need to be updated with the new 'status' automatically granted by the server. The 205 response body will normally be empty, which means that to update the browser view your response-handling code will need to:
do further ajax requests and update the relevant part(s) of your
interface with new information from the server, or
redirect the user to a new URL, or
reload the entire page.
If working with HTMX, a 200 or 201 response would include the actual html snippet of the record that you want updated on the page - and HTMX will replace it automatically for you when it receives the response. With a 205 response, you could send an HX-Trigger response header that would call a custom event on the interface elements that need to update themselves - see the examples in the docs.
CASE 2: data is invalid, data on server is not updated
The status code that needs to be returned in case of an error varies depending on what caused the error. Errors that the server believes are the responsibility of the client - such as 'sending invalid data' - have a status code in the 4XX range. Some of the common errors in that range include 404 ('Not Found'), 403 ('Forbidden'), and 'Unauthorised' (401).
In the case of a client sending data that the server cannot process because it is 'not valid' - either because the request itself is malformed, or because the data doesn't pass some business validation logic - the current advice is to return status 400 (Bad Request).
Many years ago, some people believed that the status code 400 should only be used to indicate a malformed request (syntactical error) - not to indicate a failure in business validation logic (semantic error). There was a lot of debate, and temporarily a new status code (422) was created, that was supposed to cover semantic errors, exclusively. In 2014, however, the official definition of the status 400 code was changed to allow for the inclusion of both syntactical and semantical errors - which rendered status 422 essentially unnecessary.
You can find lots of discussions and explanations online about the differences between 400 and 422, and some people still argue passionately about this to this day. In practice, however, the 400 code is all you'll need - and you can include a response body in it that explains in detail, if needed, the cause of the error.
Note that when working with HTMX, a response with a 400 code should trigger an htmx:responseError event automatically. You can trap that event, for example, to update your form interface elements, in case of data validation errors caught by the server.
Well, 200 OK and 201 Created are the best for successful result.
For invalid data I would return 422 Unprocessable Entity, because the headers are correct, but body is not (though parseable by the server). The caveat is some HTTP clients won't handle 422 properly and in this case you have to use 400 Bad Request, however, the most of the modern clients will be fine.
You have said it is not about JSON APIs, but how will you meet this type of requirement - it is not clear whether this is relevant for your scenario???
SERVER DRIVEN BEHAVIOUR
I cannot see how a client could ever decide an HTTP status code based on input data. How would the client deal with these examples?
The call is not authenticated (cookie or token) - an API would return 401 - this tells the UI to perform a retry action.
The call is not authorized - an API would return 403 or 404 and the UI would present an error display.
The data is malformed or invalid according to domain specific checks - an API would return 400 and tell the UI what is wrong so that it can perform actions.
Something went wrong in server processing, eg data cannot be saved because database is down.
MY THOUGHTS
htmx looks interesting but a key requirement before using it would be ensuring that htmx can read server side error responses and use values returned. Maybe there is an elegant way to do this ...
Maybe I am just paranoid :). But it is worth being careful when choosing technologies that there are no blocking issues. Lack of error handlng control would be a blocking issue in most systems.
I'm using htmx 1.8 with asp.net core 6.0.
This works for me.
controller:
//server side validation failed
Response.StatusCode = 422;
return PartialView("Core", product);
client side javascript:
document.body.addEventListener('htmx:beforeOnLoad', function (evt) {
if (evt.detail.xhr.status === 422) {
//
// allow 422 responses to swap as we are using this as a signal that
// a form was submitted with bad data and want to rerender with the
// error messages
//
evt.detail.shouldSwap = true;
evt.detail.isError = false;
}
});
200 OK or 201 Created are the best choice for a successful POST request.
However, for invald data, you can pass 415 Unsupported Media Type
I want to implement a system that after user signs up, user will receive an email includes a link to verify this email is for that user.
The way I generate the token for verifying the email is like this:
import (
"crypto/rand"
"encoding/base64"
)
func generateToken() (string, error) {
b := make([]byte, 35)
_, err := rand.Read(b)
if err != nil {
return "", err
}
return base64.URLEncoding.EncodeToString(b), nil
}
But what I want to ask is if this method is OK? How to make all the token generated by this method is unique ?
What is the normal way to implement this system ?
Please give me some ideas and tell me if this method of generating token is good.
Thanks.
Check out https://pkg.go.dev/github.com/google/uuid#NewRandom.
And you may want to consider storing this in a database with the email address and perhaps an expiry date / time so that the verification doesn't stay there forever. You may only want to allow people to verify within 24 hours, or 7 days and so on. Have another job that periodically cleans expired and non-verified emails.
Two points:
No, the method as presented won't guarantee them to be unique.
You don't need to have all your tokens to be unique.
To expand on these points…
You're dealing with a set of outstanding verification requests.
That is:
A request is made by the user;
You generate a unique verification token and store it into some presistent database. This is needed in order for verification to work anyway.
The user receives your e-mail and clicks that link from it which contain your token. At this point you remove the information about this pending verificaton request from your persistent storage.
As you can see, at any given time you only have several outstanding verification requests. Hence this situation has two important properties:
You only need the tokens of these outstanding requests be different from one another. It's OK to have a verification token to be the same as that of some past (or future) request.
Your tokens have to be hard-to-guess (obviously). I'm sure you already understand that.
So, the approach to generating a new token is as follows:
Generate something hard-to-guess.
Compare it with the tokens bound to the outstanding/pending verification requests persisted in your storage.
If you find an outstanding request with the same token, you have a collision so go to step (1) and repeat.
Otherwise the token is OK so proceed with it and persist the data about this request.
Once the request passed verification, remove it from your storage.
Exact algorythm for generating tokens does not matter much. I'd say an UUID or something looking like SHA-256/512 calculated over some random data is OK.
I'm looking to develop a chat application with Pubnub where I want to make sure all the chat messages that are send is been stored in the database and also want to send messages in chat.
I found out that I can use the Parse with pubnub to provide storage options, But I'm not sure how to setup those two in a way where the messages and images send in the chat are been stored in the database.
Anyone have done this before with pubnub and parse? Are there any other easy options available to use with pubnub instead of using parse?
Sutha,
What you are seeking is not a trivial solution unless you are talking about a limited number of end users. So I wouldn't say there are no "easy" solutions, but there are solutions.
The reason is your server would need to listen (subscribe) to every chat channel that is active and store the messages being sent into your database. Imagine your app scaling to 1 million users (doesn't even need to get that big, but that number should help you realize how this can get tricky to scale where several server instances are listening to channels in a non-overlapping manner or with overlap but using a server queue implementation and de-duping messages).
That said, yes, there are PubNub customers that have implemented such a solution - Parse not being the key to making this happen, by the way.
You have three basic options for implementing this:
Implement a solution that will allow many instances of your server to subscribe to all of the channels as they become active and store the messages as they come in. There are a lot of details to making this happen so if you are not up to this then this is not likely where you want to go.
There is a way to monitor all channels that become active or inactive with PubNub Presence webhooks (enable Presence on your keys). You would use this to keep a list of all channels that your server would use to pull history (enable Storage & Playback on your keys) from in an on-demand (not completely realtime) fashion.
For every channel that goes active or inactive, your server will receive these events via the REST call (and endpoint that you implement on your server - your Parse server in this case):
channel active: record "start chat" timetoken in your Parse db
channel inactive: record "end chat" timetoken in your Parse db
the inactive event is the kickoff for a process that uses start/end timetokens that you recorded for that channel to get history from for channel from PubNub: pubnub.history({channel: channelName, start:startTT, end:endTT})
you will need to iterate on this history call until you receive < 100 messages (100 is the max number of messages you can retrieve at a time)
as you retrieve these messages you will save them to your Parse db
New Presence Webhooks have been added:
We now have webhooks for all presence events: join, leave, timeout, state-change.
Finally, you could just save each message to Parse db on success of every pubnub.publish call. I am not a Parse expert and barely know all of its capabilities but I believe they have some sort or store local then sync to cloud db option (like StackMob when that was a product), but even if not, you will save msg to Parse cloud db directly.
The code would look something like this (not complete, likely errors, figure it out or ask PubNub support for details) in your JavaScript client (on the browser).
var pubnub = PUBNUB({
publish_key : your_pub_key,
subscribe_key : your_sub_key
});
var msg = ... // get the message form your UI text box or whatever
pubnub.publish({
// this is some variable you set up when you enter a chat room
channel: chat_channel,
message: msg
callback: function(event){
// DISCLAIMER: code pulled from [Parse example][4]
// but there are some object creation details
// left out here and msg object is not
// fully fleshed out in this sample code
var ChatMessage = Parse.Object.extend("ChatMessage");
var chatMsg = new ChatMessage();
chatMsg.set("message", msg);
chatMsg.set("user", uuid);
chatMsg.set("channel", chat_channel);
chatMsg.set("timetoken", event[2]);
// this ChatMessage object can be
// whatever you want it to be
chatMsg.save();
}
error: function (error) {
// Handle error here, like retry until success, for example
console.log(JSON.stringify(error));
}
});
You might even just store the entire set of publishes (on both ends of the conversation) based on time interval, number of publishes or size of total data but be careful because either user could exit the chat and the browser without notice and you will fail to save. So the per publish save is probably best practice if a bit noisy.
I hope you find one of these techniques as a means to get started in the right direction. There are details left out so I expect you will have follow up questions.
Just some other links that might be helpful:
http://blog.parse.com/learn/building-a-killer-webrtc-video-chat-app-using-pubnub-parse/
http://www.pubnub.com/blog/realtime-collaboration-sync-parse-api-pubnub/
https://www.pubnub.com/knowledge-base/discussion/293/how-do-i-publish-a-message-from-parse
And we have a PubNub Parse SDK, too. :)
I'm working on a YRS 2013 project and would like to use Twilio. I already have a Twilio account set up with over $100 worth of funds on it. I am working on a project which uses an external API and finds events near a location and date. The project is written in Ruby using Sinatra (which is going to be deployed to Heroku).
I am wondering whether you guys could guide me on how to approach this scenario: a user texts to the number of my Twilio account (the message would contain the location and date data), we process the body of that sms, and send back the results to the number that asked for them. I'm not sure where to start; for example if Twilio would handle some of that task or I would just use Twilio's API and do checking for smss and returning the results. I thinking about not using a database.
Could you guide me on how to approach this task?
I need to present the project on Friday; so I'm on a tight deadline! Thanks for our help.
They have some great documentation on how to do most of this.
When you receive a text you should parse it into the format you need
Put it into your existing project and when it returns the event or events in the area you need to check how long the string is due to a constraint that twilio has of restricting messages to 160 characters or less.
Ensure that you split the message elegantly and not in the middle of an event. If you were returned "Boston Celtics Game", "The Nut Cracker Play". you want to make sure that if both events cannot be put in one message that the first message says "Boston Celtics Game, Another text coming in 1 second" Or something similar.
In order to receive a text message from a mobile device, you'll have to expose an endpoint that is reachable by Twilio. Here is an example
class ReceiveTextController < ActionController
def index
# let's pretend that we've mapped this action to
# http://localhost:3000/sms in the routes.rb file
message_body = params["Body"]
from_number = params["From"]
SMSLogger.log_text_message from_number, message_body
end
end
In this example, the index action receives a POST from Twilio. It grabs the message body, and the phone number of the sender and logs it. Retrieving the information from the Twilio POST is as simple as looking at the params hash
{
"AccountSid"=>"asdf876a87f87a6sdf876876asd8f76a8sdf595asdD",
"Body"=> body,
"ToZip"=>"94949",
"FromState"=>"MI",
"ToCity"=>"NOVATO",
"SmsSid"=>"asd8676585a78sd5f548a64sd4f64a467sg4g858",
"ToState"=>"CA",
"To"=>"5555992673",
"ToCountry"=>"US",
"FromCountry"=>"US",
"SmsMessageSid"=>"hjk87h9j8k79hj8k7h97j7k9hj8k7",
"ApiVersion"=>"2008-08-01",
"FromCity"=>"GRAND RAPIDS",
"SmsStatus"=>"received",
"From"=>"5555992673",
"FromZip"=>"49507"
}
Source