What is the best way to create forms (textfields, checkboxes, radio buttons, ...) and handle the data after the user's input?
Just use web components as dart's web ui?
http://www.dartlang.org/articles/web-ui/
http://www.dartlang.org/docs/tutorials/web-ui/
edit: Lets imagine the following example application: I would like to create an online quiz/test.
First the user has to register
Data will be stored in a textfile or in a database
User can log in and play an online quiz or do an online test.
For that quiz/test i need to evaluate the input with the predefined correct answers
Here's a high-level answer to your question.
To handle data on the server side you can use the HttpServer class to start a web server. See this article.
To store data in a flat file you'll need to use the dart:io package to open a file and write to it. See the documentation for File.openWrite().
To store data in a database there are packages available on pub for mysql and postgresql.
There are two different ways to implement the client side. The traditional way is to use templating to generate html with the data in input elements within a form tag, and then handle the form submission in your webserver.
The modern way, that is the focus within the Dart community, is to write a single page app, which uses HttpRequest to read data from and send data to the server (usually using json).
On the client side, you could retrieve data from server (e.g. as JSON) and use that to build a form. This seems like a good fit for a web component as elements can be dynamically added based on received data.
The component would be bound to the model so you can serialize the model object to JSON on submit and send it to server on submit or just send it as standard HTML form.
The server side of the story is less clear, there are no production quality web server libraries that I am aware of, but you could take a look at DartExpress as an example, or Stream, and there are others, more or less complete. Anyway, you would have to extract the POST payload from HttpRequest (if sent as JSON) or use the form data which is also accessible via queryParameters property - please note that this is Dart:io.HttpRequest class, not Dart:html.HttpRequest, and it is available only on server side.
The mentioned server frameworks simplify this part a bit.
Using Web-UI would be a good choice. The todomvc application illustrates nicely how to dynamically capture the input from a user. Processing on the server side is wide open as far as choices go. Dart does have server side capabilities, and you could use some of the existing libraries to accomplish what you want.
Another way that you can process the information server side is to comunicate with the DB directly using a REST based web service like CouchDB. Cloudant offers such a service and allows you to communicate directly to the DB from the client, providing you can overcome the Same-Origin-Policy. There are 2 ways to do this. Enable CORS on the CouchDB instance, or host your application on the server that has the DB, which is also possible with CouchDB.
Dart serverside also supports websockets, so you can easily deliver the user provided data to the server with web sockets, and then do whatever processing you like on the serverside.
One other option I can think of would be to have the information processed and saved in the local browser. You can access the local DB or local browser file system from the Dart client, and keep everything local. For statistics, you can have the client update a web service of your choice.
Related
I am working on developing an integration with Workday. Under my initial analysis, I found that Workday provides multiple wsdls for different modules like "Human resource", "Inventory" etc. I can see this complete list at https://community.workday.com/sites/default/files/file-hosting/productionapi/operations/index.html
I am trying to understand how I get get this list progamatically in my integration so that my user can select one of the wsdls rather than typing in the full name of WSDL. Please share your thoughts on this.
You can programatically retrieve a list of all web service operations by creating a Custom Report based on the "Public Web Services" data source. The report can then be exposed as a RESTful WS for easy retrieval.
Some fields you can include in the report are: Web service, supported operations, api version, endpoint url, WSDL url, etc, etc.
This is highly customisable, in the sense that you can query the RESTful WS Report for specific versions, specific operations, etc, via Prompts / URL Params.
The report-as-a-service, supports also a variety of output formats as well as its own WSDL.
The purpose of a SOAP WSDL is to generate a client stub, i.e. a model that lets your client interact with objects exposed or consumed by the service provider. You don't interact with a WSDL at runtime - you interact with the stub. If you want to make multiple services available, you have to include each WSDL in your client application at compile time and generate their stubs. The services in a given API version do not change, so there isn't a reason to do this dynamically.
To add to the query asked, what we are trying to understand is that whether there an API call/request which we could hit to get the list of web services available to populate it on the UI to select from it.
For Example: In this link, https://community.workday.com/sites/default/files/file-hosting/productionapi/index.html, we have Absence_Management, Academic_Advising, Academic_Foundation and so on and Now, if I want it to be displayed to the end user so that He can select the webservice to be used and accordingly we could download the WSDL as to work on it.
I am new to iOS app development and am interested in developing an app that needs to utilize existing technologies to sync app specific data across multiple i-devices (iPhone, iPad, Touch, etc.). As an example, the app can be installed on multiple devices. On one device, the user will initially create an account. Then in subsequent logins, the user may create a task list, and each task item may possibly include a captured photo image. On the user's second i-device, as he logs in, he would be able to see and access the list and images (locally). Can someone explain to me what technologies I can leverage on to implement such an app?
Specifically:
How do I set up and manage the user accounts? Do I Need a dedicated server and sql database set up for my entire user base? And what programming/scripting languages do I need to learn?
How about the mechanism of pushing and pulling app data from one device to another? Do I need some kind of cloud technologies (SaaS?) to handle the storage and transferring of the data?
Any specific open source or commercial products I can leverage on?
Thanks in advance.
Kenny
I personally have not have had a situation like this, but here is what I would recommend.
You will need to have a server set up with database software.
You will need to write an api for yourself based on HTTP POST (REST) or maybe you could write a SOAP service.
I would HIGHLY recommend purchasing an SSL cert. for your server that way you can send the username and password in your request and it will be encrypted automatically.
For the api, you have a whole selection of languages and databases at your disposal. I am personally biased towards asp net with an MSSQL server.
with your api you will need to write methods to authenticate the user, and then save and send your data.
In your app you will simply send web requests to the server (ASIHttpRequest maybe?) and you can receive JSON responses back, which you can then deserialize into workable objects and vice versa.
if you do use asp net, you can use the newtonsoft JSON library to convert your objects for sending and convert received objects.
I dont remember the name, but there also is a JSON library for obj-c that is usable on iPhone.
Use a SQL server and host a database of logins and passwords.
Then, from each device, create a connection to the server, and download the login information for the account.
Also, not to be rude but: Google it.
How might I go about using a web service in an iPhone app? For example, if I wanted to use a web service that you can use to convert a value into a different unit, how would I go about doing that? For example: http://www.webqc.org/balance.php
It depends what sort of 'web service' it is. If it is a stateless REST style API, passing data in the URL and/or data encoded Json or XML it couldn't be easier, just use NSURLConnection.
Using examples I found on the web I made an application (server and iOS client) - using the NSURLConnection & NSMutableURLRequest, and encoded/decoded data using YAJL. This was pretty easy to get going.
If you don't want to do this using the core libraries directly- there are some frameworks you can use, e.g. RestKit. I've not used it, but it looks good and comes recommended.
If it is a SOAP style web service, this is a lot more complicated as SOAP services often expose a stateful API.
I should say that the example that you show here is not a web-service, whilst it does come with a way of calling it just using a URL - it returns an html page which makes it hard for you to use the results. I presume that you are more interested in a service that returns results encoded as XML or Json or the like.
As I begin building the framework of my first iPhone app, I'd like to learn more about the "standard" or preferred approach for interacting with HTTP servers. I assume most of these iPhone apps initiate HTTP connections to send and receive data. What is the preferred data format and method for going about this task?
Secondary questions: Are there other ways of sending/receiving data to a server? Should I avoid using a PHP web server as the middle man in interacting with a few databases?
Current process:
Outbound: iOS -> Http request -> PHP -> MySQL Database
Inbound: MySQL -> PHP -> JSON Data -> iOS
I would use XML to communicate with your server unless you are doing something special (Video/Audio or packaging your own data). Cocoa has built-in support for XML so it would speed up the development process.
There are other ways to communicate with the server. You could write your own protocol which would only be understood by your client (Maximum security but could be hard to maintain or bugs could be discovered). You could use someone else's framework (like JSON).
For more details about JSON, please see this link iPhone/iOS JSON parsing tutorial
You could try NSURLConnection. It is usually your best bet. It's the preferred method to access web resources. Be sure to check out NSURLConnection SSL HTTP Basic Auth to see how to use SSL. If your're debugging and your certificate is not quite trusted, check out: How to use NSURLConnection to connect with SSL for an untrusted cert?.
As for your Database question.
I personally would use a PHP Webserver that communicates directly with my Database because
1. I can change web hosting companies and my iOS app will only need to know the domain name (www.example.com/?username=abc&password=0000&uuid=000000&data=PackagedData)
2. I can upgrade my DB plan from FREE to something that can manage more connections (or the type of DB) and I just need to update the connection strings in my PHP Script (no need to update client iOS app)
Here are some scary reasons why you don't want direct communication with your database server
1. If you are storing sensitive non public data (usernames, documents, passwords, etc) then you're taking a HUGE risk. A clever hacker can reverse engineer your app and find the strings you used to connect to the DB and then gain access to your DB (without your knowledge). Possibly use the data or sell it!
If you ever decide to choose a new DB server or if your hosting company decides to give you a new IP (or sub domain for your DB Server) then you will have to update ALL your clients immediately and you may need to send them Push notifications to inform them that your App will stop working unless they upgrade.
There isn't a preferred format. Personally I like using JSON but some people swear by plists because of the speed. You can also use XML if you are more comfortable with it. I've found working with JSON REST API's very enjoyable on iOS using ASIHTTPRequest and JSONKit. It's been pretty easy to get started and the flexibility allows for some really cool stuff.
You should definitely use a PHP Server as the 'middleman' because you'd want to validate your data on the server side as you receive it. Exposing your DB directly exposes it to attacks and using PHP you could save yourself a lot of headaches and issues. Of course you can use other frameworks and languages such as Ruby (RoR, Sinatra etc.), Python (Django) and others
Your current process looks just fine to me and is what many services on the Web use to solve this exact problem.
I building a website with Ruby on Rails framework.
The site will contain a flash application that will interact with the rails application using web service.
My partner builds the flash application and he told me that the flash application interacts through WSDL file.
I am new to web services. I would like to know how to create the WSDL file, and how to make the interaction between the rails application and the WSDL file.
If you believe that there are better alternatives than SOAP/WDSL, I would like to hear them too.
Thanks,
Oded
Have you Googled how to build web services in Ruby? Here are a few links that come up, all addressing exactly what you want to do:
http://www.tutorialspoint.com/ruby/ruby_web_services.htm
http://www.ibm.com/developerworks/opensource/library/os-ws-rubyrails/index.html
http://searchsoa.techtarget.com/tip/Web-services-with-Ruby-on-Rails
How about you take a look at some of those links, and come back to us if you have further questions.
I do have one elaboration:
My partner builds the flash
application and he told me that the
flash application interacts through
WSDL file.
It sounds like your partner has an incomplete understanding of how Flash can access remote data services. Using a SOAP Web Service with a WSDL is one method, for sure, and here is some documentation on that.
A Flex / Flash application can also make standard HTTP calls, sometimes called REST Web Services. In many cases, REST Web Services will return an XML Document, but that is not required. Any data, including simple text data, can be returned from a REST Web Service.
What many people prefer to do is to use an AMF Gateway with RemoteObject. AMF is a binary format so you'll get much smaller file size transferred back and forth than the alternatives. It also provides for automatic object translation between your server side objects and client side objects. This can be a time saver in development because you don't have to parse data to turn it into something Flex can use easily. RubyAMF is one Ruby implementation of AMF.
You'll be going through more pain than you need to by using WSDL.
Instead, I recommend creating a REST interface that returns json (or xml) -- you'll find in rails it will just work.
So you'll have things like:
/books # returns a list of books. Also do Searching here
/books/1 # return the detail of a book with ID of 1
Search for "REST Rails" and you'll get examples of controllers that will return JSON and XML depending on what the client requests.