I'm trying to learn and use Fuchsia for fun, and a pretty basic concept is keeping me from progressing.
I thought that, as a learning experience, I could write a simple HTTP client that prints the content of some random URL to the log. Really nothing fancy.
As I understand, using the network (in my case I'd like to utilize fuchsia.net.http.Loader) is a capability, which has to be granted to a running component. Makes sense, that's pretty much the core of the OS.
I also understand that the initiating component, the one that runs my component, needs to grant this capability to my component. That's fair.
What I don't understand, and I'd very much appreciate any additional information (pretty please!) is how I can grant this to my component?
Specifically all demos and examples I saw had a custom client & server under a realm, which talked to each other. That's a good practice, but it doesn't bring in any capability that's built in.
What am I missing? Thanks in advance!
I'm trying to learn and use Fuchsia for fun, and a pretty basic concept is keeping me from progressing.
Thanks for your interest in Fuchsia! First of all, if you haven't already gone through Fuchsia Fundamentals I would strongly suggest that as a starting point for many of the foundational concepts.
Specifically all demos and examples I saw had a custom client & server under a realm, which talked to each other. That's a good practice, but it doesn't bring in any capability that's built in.
This is primarily because there's isn't necessarily a concept of any set of components or capabilities being "built in" to the system. The capabilities available to components in the system are entirely dependent on the rest of the components in a particular product build and how they are organized (this is called the component topology).
I thought that, as a learning experience, I could write a simple HTTP client that prints the content of some random URL to the log. Really nothing fancy.
The answer has a few sharp edges to it at the moment, as Fuchsia is a rapidly evolving open source project. Hopefully some of the details below will help you move forward.
Determine the capability routes
So you'll have to do a bit of work to figure out where the capability you need is provided and routed. In fact, one of the components exercises shows you how to do this for the fuchsia.net.http.Loader capability. Knowing where a capability is offered/used allows you to determine where your component would need to be instantiated to obtain the necessary capability.
You might also find some of the content in the Connect components developer guide useful in accessing the capability.
Run the component
Knowing where a capability is routed allows you to determine how to run your component. The most straightforward way of instantiating a component in the topology is to do so dynamically using ffx component. However, this requires a collection somewhere on the system with the capabilities you need. The ffx-laboratory realm where most examples are run has a very limited set of capabilities that does not include fuchsia.net.http.Loader.
You'll likely need to add your component statically to the topology using a core realm shard so that the necessary routes can be declared explicitly between the components that offer fuchsia.net.http.Loader and your component. With the component included statically in your product build, you can execute it using ffx component commands.
For more details on component execution, check out the Run components developer guide as well.
Run a CLI binary
Since this is a learning exercise, another option is to build your code as a binary that runs within the context of a component that already has the capabilities you need vs. creating and running an entirely new component. This is commonly used for CLI tools. With the ffx component explore command you can run your code as a binary inside the existing component that provides the HTTP capability you are looking for using the --tools argument, without the need to work through all the capability routing pieces described above.
For more details on ffx component explore, see Explore components.
Related
I'm building a new Laravel 8 application and given the reactivity features available with Livewire package, that essentially turn a backend developer into a full-stack developer (no advanced Javascript knowledge needed), I don't use any POST actions or request handling logic in my scripts. Every CRUD operation is handled with modal windows and AJAX requests. So my question is: Are there some drawbacks in this approach? Are there some limitation that will emerge in the future from the fact that my scripts don't directly handle HTTP request?
Thanks for your opinions.
FYI I'm not familiar with Laravel or Livewire. I'll use the term "platform" below as a general word to encapsulate technologies and libraries, etc, such as what you describe.
Platforms tend to focus on the high-value scenarios that most people need - so as long as what you need the platform to do aligns with what it can do, you're fine (e.g. simple CRUD). But, if you need to do something that pushes the boundaries of what the platform can do then you'll run into issues: it may not be possible; it's possible but really inefficient / a pig to work on; distorts your architecture and decision making.
Platforms like this are good in that they hide complexity, which is great until you need to access it and look under the hood. This applies to everything from debugging to developing features using approaches that the platform / platform designers haven't allowed for.
As a new developer, learning how to do things "the long way" (e.g. hand-code AJAX calls) is great as a learning experience. By doing that you can better appreciate how platforms like the ones you mention work - because you understand the underlying principles. So, a disadvantage is that new developers won't get that experience through working on this solution - they'll have to do that as a side project (which is not "evil", but it is a consideration).
I'm aware of Etherscan's capability for interactions with smart contracts on the Ethereum network, but I wonder if there is any other way to read and write from smart contracts.
I'd expect an improved UI/UX usability, allowing input validation, adding documentation on top of the contract etc, yet I couldn't find any other service providing it.
You could use https://remix.ethereum.org/
There is no service that I know that can provide documentation on top of the contract.
But, it's possible to develop one. Are you interested in how it can be done?
The only one I know of is Remix. This is a great tool for smart contract testing and interaction
And if you are planning to develop your own UI with an API. This is not the exact solution but check out drizzle. It has some good built in features which will get you started on the front-end parts and showing blockchain data
Both tools presented below load the ABI automatically from the contract address.
eth95.dev
There is one that looks like old Windows 95 app. Pretty cool.
https://eth95.dev/
mycrypto.com
https://app.mycrypto.com/interact-with-contracts
I want to ask this because I want to know developer perspective about developing from scratch mobile games.
Let's say the project is already going to start its development.
I am already aware of the specification of the project example.
Logic, Browser/devices to support, IDE to be used.
What should be the first thing to do.
Create the UI/UX designs for all devices with no functionality
and after the designs are finalized then integrate functionality
Create functionality logic then do design
Do design and functionality together
which of these will save much more time.
please share your experiences about this development and how to make out of it
so that failure of delivering the project will be at its minimum errors
Every of these aproaches may work, however I will tell you about my experience.
I did a lot of different projects using points you provide in the question, but for me the easiest and most successful approach was logic first, design second.
How to start using this approach?
Think about use case at first. For example, user should be able to register in the game.
Implement database structure(if needed). For example, create table 'Users'.
Implement data access logic. For example, write code that saves a username and a password.
Create service layer with use case's (business) logic implementation . For example, you can write saveUser method.
Create a simple(ugly) UI that allows you to feel the use case and to test it.
Pay guru designer to create clean design. For example, a design of the registration page.
Сontinue with step 1.
Advantages?
Allows to create really working MVP with ease.
UI manipulates only real and dynamic data.
Allows you to build foundation first.
All,
I'm currently revamping an ancient IVR written using Classic ASP with VXML 2.0. Believe me, it was a mess, largely due to the mixing of routing logic between the ASP code and the VXML logic, featuring multiple postbacks a la ASP.NET. Not fun to debug.
So we're starting fresh with MVC 3 and Razor and so far so good. I've succeeded in moving pretty much all the processing logic to the controller and just letting most of the VXML be just voicing a prompt and waiting for a DTMF reply.
But, looking at a lot of sample VXML code, it's beginning to look like it might actually be simpler to do basic routing using multiple on a page and VXML's built-in DTMF processing and . More complex decision-making and database/server access would call the controller as it does now.
I'm torn between the desire to be strict about where the logic is, versus what might actually be simpler code. My VXML chops are not terribly advanced (I know enough to be dangerous), so I'm soliciting input. Have others used multiple forms on a page? Better or worse?
Thanks
Jim Stanley
Blackboard Connect Inc.
Choosing to use simple VoiceXML and moving the logic server side is a fairly common practice. Pros/Cons below.
Server-side logic
Often difficult to get retry counters to perform the way you want if you are also performing input validation (valid for grammar, but not for host or other validation logic)
Better programming language/toolkits for making logical descriptions (I'm not a fan of JavaScript, but even if you like JavaScript, you tend to have to create a lot of forms to get the flow control you want).
Usually easier to debug. Step through logical decisions and access to logging tools.
Usually easier to create reusable components that use parameters to alter component behavior.
Client side logic
Usually more scalable. VoiceXML browsers tend to use a large amount of their resources compiling and processing pages. One larger page will typically do better than a variety of smaller pages. However, platforms vary significantly and your size may make this negligible.
Better chance of using static pages. Many platforms have highly optimized caches (more than just fetched data). Like above may only matter if you have 100s of ports per device or 1000s of ports hitting a server.
Mixing and matching isn't bad until somebody requests some sort of global behavior change. You may be making the change in multiple places. Debugging techniques will also vary so it may complicate your support paths (e.g. looking in browser logs versus server logs to see what happened on a call).
Our current framework currently uses a mix of server and client. All our logic is in the VoiceXML, and the server is used for state saving and generating recognition components. Unfortunately as all our logic is in the voicexml, it makes it harder to unit test.
Rather than creating a large voicexml page that subdialogs to each question and all the routing done on the clientside, postback to the server after each collection, then work out where to go now. Obviously this has it's pros/cons as Jim pointed out, but the hope is to abstract some of the IVR/callflow from the VoiceXML and reduce the dependency on skilling up developers in VoiceXML.
I'm looking at redeveloping using MVC3, creating different views based on base IVR functions, which can then be modified based on the hosting VoiceXML platform:
Recognition
Prompts
Transfer
CTI Get/Set
Disconnect
What I'm still working out is how to create reusable components within the MVC. Whether to create something we subdialog to and return back the result (similar to how we currently do it), or redirect to a generic controller, and then redirect to the "Completed" action once the controller is done.
Jim Rush provides a pretty good overview of the pros and cons of server side versus client side logic and is pretty consistent with my discussion on this topic in my blog post "Client-side versus Server-side Development of VoiceXML Applications". I believe the pros of putting the logic on the server far outweigh putting it on the client. The VoiceXML User Group is moving towards removing most of this logic from VoiceXML in version 3.0 and suggesting using a new standard called State Chart XML (SCXML) to handle control of the voice application. I have started an open source project to make it easier to develop VoiceXML applications using ASP.NET MVC 3.0 which can be found on CodePlex and is called VoiceModel. There is an example application in this project which will demonstrate a method for keeping the logic server side, which I believe greatly improves reuse of voice objects.
I want a real and honest opinion what do you think of Google Visualization API?
Is it reliable to use becasue when i was reading the documentation i noticed that there are alot of issues and defects to overcome and can i use it to retrieve data from mysql database.
Thank you.
I am currently evaluating it. As compared to other javascript data visualization frameworks, i think it has a lot going for it:
dynamic loading is built-in
diverse, many things to choose from.
looks really great!
framework mostly takes care of picking whatever implementation fits the current browser
service based, you don't need to download anything in advance
unified data source: just create one data table, and have multiple visalizations draw from that data.
As a disadvantage, I'd like to mention security. I mean, because it's all service based, it is not so transparent what happens when you pass data into these API calls. And as far as I know, the API is free, but not open source, so I can't really check what is going on behind the covers.
I think the Google visualization API really shines if you want to very quickly whip up a visualization gadget for use in a blog or so, and you are not interested in deploying all kinds of plugins and libraries (for eaxmple, with jQuery based frameworks, you need may need to manage multitple javascript libraries that work together to deliver the goods). If on the other hand you are creating an application that you want to sell, you might want to keep more control over what components you are using, and I would probably consider using something like Flot
But like I said, I am only evaluation atm, I am not using this in production.
Works really great for me. Can be customized fairly easily. Haven't seen any scaling issues. No data is exposed so security should not be an issue. - Arunabh Das
One point I want to add here is that, Google Visualization API cannot be downloaded, its not available for offline usage. So application which is going to use it must be always connected to internet, otherwise I think it wont be able to render charts. Due
to this limitation, this API cannot be used in some applications for which internet connection is not available.
I am currently working on a web based application that will have the Google Visualization API added to it and from the perspective of a developer the Google Visualization API is very limited in what you can do with each individual Chart and if I had a choice I would probably look at dojox charting just because of the extra flexibility that the framework gives you.
If you are doing any kind of large web application that will use charting extensively then I would not recommend the Google Visualizations API it does not have enough flexibility for a large web application.
I am using Google Visualization API and I want to stress that they still won't let you download it, which means if their servers are down, your app will be down if you depend on it. I have been using it for about 4 months, and they have crashed once me once so I'd say they pretty reliable and their documentation is really nice.