I minted my NFT through my own smart contract successfully. But I don't know how to get my NFT's transfer history like polygonscan do. Is there any API or functions to get NFT history?
Some documents said that I should make a event listener which detect the owner is changed. Is it work even I sell my NFT on my own web site and opensea?
It depends on the specific marketplace or website. But generally, most marketplaces invoke the transferFrom() function on the collection contract during the sale, effectively emitting the Transfer event, that you can handle in your offchain app.
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I got confused with the right data flow when I have a backend API and a redux state that passing the data to the components.
The question is: What is the right methodology to handle 2 data resources, API and Redux?
should I update the state and then fire a send request to the API with the update?
or, let the redux send that request for me every time the state changes?
or, should I update the API directly and then fire a get request to update the Redux store?
I'm really confused and do not know what is right approach should I take with less error in the future use
Appreciate any help, even sending me an article that talks about this issue and I'm gonna read it
Thank you
should I update the state and then fire a send request to the API with the update?
That's called "optimistic update", the advantage is that your app feels fast and responsive, since the network delay is hidden from the user. The downside is that the request might fail and you have to undo what the user did and inform them that it failed. For simple operations (for example marking a product as a favorite in an ecommerce website) this works great in my opinion.
To explain how it works with the example in mind:
User action triggers update of redux state (product is immediately shown as favourite on the page)
At the same time, an API request is fired to favourite the product on the backend side.
You fetch the product data again from the API and render it
Now either the request has successfully changed the product, so visually nothing changes on the page for the user - to them it looks like the operation happened without network delay - Or the request failed and you show the old state where the product is not a favourite and and error message appears.
or, let the redux send that request for me every time the state changes?
Parts of redux-toolkit embrace this approach if I'm not mistaken. If you decide to go down this road, I'd recommend to not implement it yourself but instead rely on existing libraries/middlewares.
or, should I update the API directly and then fire a get request to update the Redux store?
This is the classic, safe, and simple approach.
My advice is:
If you have lots and lots of CRUD operations against your API, and you want to not write lots of boilerplate code, look into redux-toolkit (specifically https://redux-toolkit.js.org/rtk-query/overview ).
If you care about perceived performance of your app, try optimistic update.
If you want to keep it simple and just get things to work, follow the classic approach.
(this was originally a post on the flutter-dev reddit that was redirected here)
So I started making this flutter app using firebase as a backend and after looking at all the options for state management I finally realised that the tools provided by firebase already handle pretty much everything I would need state management for.
For example:
I could set the currently logged in user in my state to show the right login or home page and make the user uid available to widgets for their firestore API calls.
OR
I can just listen to FirebaseAuth.instance.onAuthStateChanged to show the right page and just use FirebaseAuth.instance.currentUser() from anywhere to get the logged in user uid and do my firestore calls.
What I mean is, for every thing that would require global state, I can just basically have a firebase stream listener.
Is this right ? Or am I missing something here ?
You're not missing anything. Since most Firebase APIs rely on data from Google's servers, many of them are designed to be used in a reactive way. Making your UI reactively respond to those asynchronous changes is (in my experience) the best way to keep your code simple.
There may be slight behavior between the different types of listeners. But the onAuthStateChanged listener immediately fires with the current state when you attach it, which makes it a good example of a listener that you can use everywhere you need to respond to auth state (instead of also storing that state somewhere in your app).
In that scenario I would say yes, you can read the onAuthStateChanged stream and react to changes. But there are also scenarios where I need a stream for interacting between widgets without a parent/child relationship. For example, in one of my apps I have a company selector, and the rest of the app reflects to the selected company. I created a stream, so that the company selector doesn't need to be a parent of the other widgets, and especially so that I don't need to pass the company parameter to all the widget tree.
I also have one scenario where I need to load extra information about the user that isn't available on the FirebaseUser object. So when the user is logged on I load their information from a "users" collection and then I add that to a custom stream.
So to conclude I would say yes, you should use the default Firebase streams when possible, but that doesn't mean you can or should use that solution for everything.
I want to integrate Marketo api with my .net project.
My client has given a username & password to Marketo. I want to retrieve "opportunities" from Marketo. I have written code for that. Currently there are not any opportunities so I'm not able to test my code. Has anyone an idea how to create opportunities in Marketo so I can whetehr check my code is retrieving that records or not?
Opportunities are not visible as standalone entities in Marketo as they are in SFDC or other CRMs. Rather, as #joev said, you have to find a lead that has an opportunity and view the opportunity details within the context of that lead's detail view, on the Opportunity tab.
If you want to use the GUI to create an opportunity, the right place to do that would be in the CRM — not in Marketo.
You need to have create/update right via API, ask your client for create/update rights then you will be able to create some data through API itself.
Like other people have mentioned there isn't a direct GUI inside Marketo for creating opportunities. These are typically created via the CRM (aka Salesforce, NetSuite, Microsoft Dynamics, etc...) and then sync'd to Marketo.
If you want to test it and have no CRM available -- technically you can just use the REST API to sync your own opportunity to a lead. Once done you could login to Marketo to visually validate it. Then now that you have an opportunity created you could then use the API to GET the opportunities and further validate your integration.
Here is a link to Marketo's documentation on how to sync an opportunity to Marketo. Also on that page is the documentation on the other REST API options.
All,
I have completed the basic GAE "Guestbook" example which uses Google Cloud Endpoints and Google Cloud Messaging. I can successfully add a note to the guestbook and have it appear on all registered devices.
I've also used the super simple Server Sent Event (SSE) mechanism to have a web page initiate an event source and then update itself as events are received. But separate web pages appear to create their own distinct event sources (even if using the same URI to the event source) and thus get their own events at their own times.
The objective here is to create a bit of collaboration such that user actions can come from an android device or a web page and the effects the received action are then pushed to all connected users/devices/web pages.
I have assumed I will need a background module and that both Endpoints and 'normal' web pages / queries would channel the received user action to that background module. I believe I can get that far. Next, I need the background module to trigger a push notification to all interested parties.
I believe I can trigger a Google Could Messaging event to registered Android devices from that background module.
But it isn't clear to me how a background module can be the source of an SSE, or how the background module can best communicate with a foreground module that already is the source of an SSE.
I've looked at the Google Queue API, but I have a feeling I'm making something quite easy much more difficult than it needs to be. If you were not going to 'poll' for changes from a web page... and you wanted to receive notifications from an SSE source when changes were made by other users, possibly using Android devices rather than a typical web page, and the deployed application is running on the Google Application Engine, what would you recommend?
Many thanks,
Randy
You are on the right track, not really sure why you are using the background module but from what i understood you need to:
Your front end module receives an update
You retrieve a list of all devices receiving that update
Use the Queue service to send the update via GCM to every single device
Why use queues? because front end instances have a 1 min time limit per request and you'll need to queue work in order to go beyond that time to serve you (potentially) thousands of users.
Now, If you already have a backend instance (which does not have the 1min limit) you could just iterate over the list and send all messages on one request. I believe you have a 24 hr request limit so you should be OK. But in this scenario you don't have need for the front end module, you can just hit this server straight up.
I came across this site in alfresco discussing publish/subscribe notifications within alfresco and was wondering if there were any progress on it or someone had created an add-on
http://wiki.alfresco.com/wiki/Publish_Subscribe_Content_Notifications
Only type of notification I've read thus far from the wiki or forums is email or using rss feeds. The CMIS specifications does not encompass this and alfresco web services does not include any such methods.
We have several web applications that need to download content once a document has been uploaded and transformed in alfresco. I could develop an action to push the documents to the appropriate app, but that would require me to know every endpoint. At this point there are only 3 application but there are requirements to add additional ones in the future. Having a publisher/subscriber model would make the solution more scalable and easy maintenance in the future
What if you wrote a custom action that adds a message to a queue. You could have the queue/topic name configurable so that when someone configures a rule on a folder, they can specify which queue to put the message on. Your apps can then subscribe to the queue and act appropriately.
You could also do something similar as a step in a workflow.
Maybe the message would be something simple like the nodeRef or the CMIS object ID.