I started to develp a new project with CQRS/ES. As I understand, one command raised a new event. So, I developped a web api with one action mapped to one command.
List of api action :
[Route("api/user/create"), HttpPost]
public Task<IActionResult> Handle(Commands.Create command)
=> HandleCommand(command);
[Route("api/user/update/name"), HttpPost]
public Task<IActionResult> Handle(Commands.UpdateName command)
=> HandleCommand(command);
In my IHM project developped with Blazor, how to communicate with the web api ?
Foreach change in a textbox, i send a http post ?
it's not really a best solution.
I prefer to add a submit button and send one http post. For this solution, how do I communicate all of user's action to web api ?
I would strongly suggest you to take a look at concepts like DDD. The first thing you have to do is get a clear understanding of your Domain.
Let's say that you're working on a Product Inventory system. In your Blazor app you might well have a "create product" page, containing a form with all the relevant fields (eg. "title", "description", "price" and so on).
The backend would expose a POST endpoint /products accepting a CreateProductDTO (check what a DTO is if you're unsure). The DTO would then be mapped into an immutable command, which will then get sent to the relative handler.
The idea is not to send every single user interaction to the server. You have to make a map of the possible actions exposed by your Domain and work your way up.
Related
Context: Web application developed with ASPNet Core over ABP 2.9 framework (Razor pages).
I need to validate a model (it implements Validate(...) from IValidatableObject and calls the application service to perform some validations), then call an application service, and finally show a success message (with the same look & feel as abp.notify.success(...)).
Purpose of this post: To validate whether I am following the best practices or doing things in the correct way with ABP framework. If so, there are some suggestions to ABP team.
What I've tried:
1.- First, I tried submitting the form, but I didn't find an easy way to show the success message (like abp.notify.success ones) from the server method: public virtual async Task<IActionResult> OnPostAsync().
It would be nice to have a simple way to send client messages (like abp.notify.success ones) from server side. Maybe there is a way and I didn't find it.
2.- Second, I tried to cancel form submission and peform validation in client side, call the application service and show the message, also from client side. The issue here is that validations on public IEnumerable<ValidationResult> Validate(ValidationContext validationContext) method were not executed from client side calling form.valid().
Possible improvement to ABP framework would be to enable an easy way to perform same server DataValidation() from client side. Maybe it exists and I didn't find it.
3.- Finally, I did the following:
a) Server side: to perform ValidateModel() and call the application service (see cshtml.cs code).
b) Client Side: avoid form submission and submit it with ajax, and finally show the success message with abp.notify.success(...)) (see javascript code).
Here are the questions related to previous issues. I appreaciate your comments or suggestions:
1.- Is there any better way to perform this scenario using ABP framework utils?
2.- Am I following the best practices? (placing the classes and logic in the correct layers)
DTO with data annotations in Application.Contracts layer.
DTOValidator class that inherits from DTO and IValidatableObject and implements Validate(...) method in Application.Contracts layer. This is to keep simple DTOs between client and application services.
Model class that inherits from DTOValidator and is binded to form in .cshtml.cs (Example: public class IndexPolicies : UpdatePolicyDtoValidator {})
You can cancel form submission and directly call application service. Then use DataAnnotations to validate your dto. If you need custom logic in validation, you can validate it in application service method (or create a custom DataAnnotation).
See https://docs.abp.io/en/abp/latest/Tutorials/Part-1?UI=MVC#dynamic-javascript-proxies for best way to call application service from javascript side.
Dealing with another issue I have found a solution that solves the problem taking full advantage of the ABP framework::
a) Server side: to perform ValidateModel() and call the application service (same as described on my third try).
b) Client Side: to use a simple button instead of submit one and call abpAjaxForm(options) with abp.notify.success() on success function. Then submit the form:
var _defaultPoliciesForm = $("#DefaultPoliciesForm");
var _saveButton = $("#SaveButton");
_saveButton.click(function (e) {
var options = {
beforeSubmit: function (arr, form) {
_saveButton.buttonBusy(true);
},
success: function (responseText, statusText, xhr, form) {
abp.notify.success(l("UpdatedSuccessfully"));
},
complete: function (jqXhr, status, form) {
_saveButton.buttonBusy(false);
}
}
_defaultPoliciesForm.abpAjaxForm(options);
_defaultPoliciesForm.submit();
});
Hope it can be useful to others with the same issue. Anyway, I remember my suggestions to ABP team:
Ability to send client messages like abp.notify.success(...) ones from server side.
Ability to perform same server validation as DataValidation() from client side
Thanks for your time , I have a simple question, in an asp.net MVC application, inside controllers is it possible that along with some methods returning View (ActionMethods) other could act as (or return) Json as a Web API (could be called from external apps).
Just trying to do a proper separations, hence trying to understand.
Thanks much.
You can make an action function like an API. Try something like the this.
// Controller/Action
[HttpGet]
public ActionResult IAmSpecial()
{
if (Request.IsAjaxRequest())
{
string[] objects = new string[] { "Foo", "Bar" };
return Json(objects);
}
return View();
}
This will return the IAmSpecial view if you browse to {domain}/{Controller}/IAmSpecial while it will return a JSON result if you use an AJAX Http Get request on the same url.
while it is possible to have controller methods which return Json data only, there are a number of considerations when you want to expose that data outside of the UI app.
Since you have an MVC app, I expect you have users and a way to login. Your controllers would more than likely be secured in some way, which works for the internal users of the application. Now you want to add one method which effectively becomes an API, available outside of the application and calls to it will have to be authenticated somehow.
What I would suggest is to split this up. You can create a separate project, which is a WebAPI one, in the same solution. The code which prepares the data can live in a class library you can then reference in both your MVC and WebAPI projects.
Your MVC app can call it and then return a view with that data, the WebAPI calls it and simply returns the data. You can now decide on a way of securing your API, maybe using Identity Server or some other way and you can keep adding things to it, without affecting the UI layer.
Your second option is to make the MVC app use the API when it needs to retrieve data, so both your public clients and UI use the same thing.
Whichever option you use, the idea is to not duplicate anything and at the same time provide the security layers you need.
I have a simple asp.net web application project. Which has an order.aspx page showing different items. I have managed to show those items by outputting in
page_load event.
Now I am using JQuery to load item details from the database and show when the user clicks on the items.
This is the JQuery I am using
$(".item").click(function(){
$.post("Lookup.asp",
{
Id: $(this).id
},
function(data, status){
alert("Data: " + data + "\nStatus: " + status);
});
});
Now I want to know how and what is the best way to setup the backend part to provide the data. Currently I am thinking that Lookup.aspx page on its page load event will receive the id from request object, I query the db populate the data and send it back through the response object. I am not sure if this is the right way of doing it.
I have not set this yet, because I was thinking if we create a separate page to do this then I will have to create more pages for other type of queries (I will have different queries like checking for status of an item in db).
Another problem I was thinking with this approach will be that there will be pages which are just serving the data and we dont want to show them to the public. If someone will have the name of the pages they can access them which we dont want.
And I am using Entity Framework it that matters in anyway.
For the Web Service part. The best and easiest way to go is WEB API. Just write a controller method and it becomes a web service which returns json or xml.
Using Web API with ASP.NET Web Forms
Now about the second part is tricky.
IF your users are not logged in then , the method has to be public in order for someone to have access . So either through ajax either from just having the url someone will and must be able to access the method.
A way to tackle this , is to encrypt-decrypt your product ID's .
Or use authentication on web api.
https://www.asp.net/web-api/overview/security/authentication-and-authorization-in-aspnet-web-api
I am working in an environment with many teams who are responsible for specific content on pages. Each team is sharing specific information (common class libraries, and master pages) that each are going deliver different types of content.
Is it possible for an MVC application to do something similar to RenderPartial and pass a model to another MVC application Controller/Action to return content?
So the code for this might look like:
(http://www.mydomain.com/Home/Index)
<% Html.RenderAction("ads.mydomain.com", "Home", "Index", AdModel) %>
Maybe this is not a good idea as another thread has to spin up to server a partial view?
No, RenderPartial/RenerAction can only load views that it can access via reflection, not via HTTP requests to external resources.
If the MVC app for 'ads.mydomain.com' is available to you at compile them then you can utilise its resources via Areas, however it won't pickup the changes if they release a new version to the 'ads.mydomain.com' website without you getting their latest assembly and re-compiling and deploying your app as well.
You can do similar stuff with AJAX where you can load a fragment from another site, however it wouldn't be done server side, and would require the client to have javascript enabled. Also the model would need to be converted to JSON and posted to the request, so its a bit of a hacky solution.
You could write an extension method (lets call it Html.RenderRemote) which does all the work for you of creating an http connection to the target and requests the URL. You'd have to serialize the model and send it as part of the request.
public static string RenderRemote(this HtmlHelper, string url, object model)
{
// send request to 'url' with serialized model as data
// get response stream and convert to string
// return it
}
You could use it as :
<%= Html.RenderRemote('http://ads.mydomain.com', Model');
You wouldn't be able to take advantage of the routes on the remote domain, so you'd have to construct the literal URL yourself, which means if they change your routing rules your URL won't work anymore.
In principal yes, though your question is a little vague.
Have a look at "portable areas" within MvcContrib on codeplex. This technique allows separate teams to develop separate MVC apps that would then be orchestrated by a central application.
Please consider the following scenario,
There are two web applications App1 & App2. A user would submit his information on App1 though a form. On click of a specific button/link on App1, the same data should be posted to a page on App2 and the user should also be redirected to the same page on App2.
I would like some help in finding out the best way to implement this functionality.
One of the approaches that I have already tried out is by creating a temporary HTML form at runtime, setting the action attribute of the form to the App2 Page and get the form posted by using javascript submit. The data can then be fetched on App2 page by using the response.form object.
This approach works well, but i was still wondering if there is any other way to implement the required functionality.
I would really appriciate if you can give some insights on using RESTful webservices to implement this, or else, using some HttpModule to intercept requests at App1 and modify redirect response to app2 or any other approach that you might find fit for the purpose.
Edit:
Using querystring isnt an option for me.
I've had a need to do similar things with feed agregation and building rss feeds from web page content on different domains.
User Gets app1 page, fills in details and submits then on the server for app1 I have a method that looks like this ...
HTMLDocument FetchURL( string url )
{
WebClient wc = new WebClient();
string remoteContent = wc.DownloadString(url);
// mshtml api is very weird but lets just say you have to do things this way ...
HtmlDocument doc = new HTMLDocument();
IHTMLDocument2 doc2 = (IHTMLDocument2)doc;
doc2.write(new object[] { remoteContent });
return (HTMLDocument)doc2;
}
This function does 2 things of use ...
It gets the page of content at "url"
It parses that content in to a HTMLDocument object
Once you have this function you can then call it passing it the url to the remote page and get back a html doucment.
The functions in the HTMLDocument object will allow you to do javascript like dom queries such as :
docObject.GetElementById("id");
I then have different functions that do different things with this object based on the page / site i'm returning data from.
There is however one fatal flaw here ...
This is likely to work really well with sites that don't change much in structure and are built by code but not so well on less dynamic sites.
With stackoverflow for example its easy to pull out a question and the accepted answer for that question so I could use this code to pull and publish content from here on my own web site.
However ...
This is not going to help you for user / login related details as this sort of information is not shared to generally everyone.
It's bit like me going and trying this to link facebook profiles to my own website, I would have to go through some form of api that asked the user to authenticate their details before making the request.
simply pulling a web page based on a url only will give the other site no authentication information unless that site accepts the user login details in the quesrystring and you already have them.
You may however be able to chain requests by ripping apart my sample method, requesting the login page parsing the results, filling in the form, then posting back using the same web client instance to login then requesting the url.
The idea being that you would have a form that asks the user to put in their login details for the remote site on your site then you go and find their profile page based on that.
This would be best farmed out to a class rather than just a simple method like i have here.
In my case though i was only after something simple (the bbc top 40 uk charts) which i pulled information from not only the bbc but places like amazon, google, and youtube, then i built a page :)
It's neat but serves no functional purpose other than pulling all your other fave sources of info on to 1 page.
If you are already committed to using javascript, then why not an ajax post, and change the window.location based on the response?
You can use HttpServerUtility.Transfer this will preserve your form contents and transfer the user to the new page.
http://msdn.microsoft.com/en-us/library/system.web.httpserverutility.transfer.aspx
I have built something like what you are describing, and I found that using a <form> tag to POST to app2 is the most reliable way... basically, the way you found that worked well.
If App2 is residing on a different domain, it's usually best to create your own interface for the submission, and have that interface handle the posting from App1 to App2.
(Browser) -> Submits form to App1 ->
(App1) -> validate input
-> stores local info
-> creates an HttpRequest/POST object
-> posts to App2
(App2) -> handles the post
<- returns the response
-> confirms the results of App2
<- returns the results to the browser.
In essense, you want to control and proxy requests from your Applications domain to any outside interfaces as much as possible.
Note: I'm answering my own question
just to have a correct answers marked
against it. All the suggestions
provided by various members here are
correct in their own way, but they
were not apt for my requirements.
Hence, I cant accept any of them as
correct.
The way I have Implemented is by creating a custom control which would have a configurable property containing the URL to post data and another one accepting a dictionary object as the data input to be posted.
This control would internally create a HTML form with action attribute set to the URL specified by the user and have the data feilds created out of the dictionary object. This form would then be posted on the button click event on the page hosting this control.