Edit: The below code actually does work. Hopefully this will still be useful as an example.
Is there a way to write two different controller methods for the same URL, with one handling normal requests, and one handling post requests? Like this:
#RequestMapping("/url")
public String requestWithoutData() {
return "view";
}
#RequestMapping(value="/url", method=RequestMethod.POST)
public String requestWithData(#ModelAttribute("foo") String foo) {
System.out.println(foo);
return "view";
}
When I run code similar to the above it always defaults to the requestWithoutData method. How can I get spring to differentiate between the two? I know I could just use one method with if statements but this way seems nicer if possible. Thanks in advance!
yes you can have two methods with same url but different RequestMethod. In first method you need to have method attribute.
#RequestMapping("/url", method = RequestMethod.GET)
public String requestWithoutData() {
return "view";
}
#RequestMapping(value="/url", method=RequestMethod.POST)
public String requestWithData(#ModelAttribute("foo") String foo) {
System.out.println(foo);
return "view";
}
Related
How to require/validate parameters for actions. Right now I have lot of actions that looks like this (which is horrible):
public ActionResult DoSomething(string paramA, string paramB, string paramC)
{
if (string.IsNullOrWhiteSpace(paramA))
{
return JsonResult(false, "paramA is missing");
}
if (string.IsNullOrWhiteSpace(paramB))
{
return JsonResult(false, "paramB is missing");
}
if (string.IsNullOrWhiteSpace(paramC))
{
return JsonResult(false, "paramC is missing");
}
//Actual Code
}
How to encapsulte this (potentially "globally")? I know that its possible to wrap parameters to model and use ModelState.IsValid like in this post: https://stackoverflow.com/a/39538103/766304
That is maybe one step forward on same places but generally I don't that it's realistic to wrap all parameters to models everywhere (~1 class definition per 1 action method... how nice is that?).
Also this is again per action ceremony which should be handled somewhere centralized:
if (ModelState.IsValid == false)
{
return BadRequest(ModelState);
}
The easiest way to do it would be to create a model class and use [Required] attributes like this:
public class FooModel
{
[Required]
public string ParamA {get;set;}
[Required]
public string ParamB {get;set;}
[Required]
public string ParamC {get;set;}
}
And then use it in your controller like this:
public ActionResult DoSomething(FooModel model)
{
if (!ModelState.IsValid)
{
// return some errors based on ModelState
}
//Actual Code
}
If you are looking for more global approach, then i believe you could look into Action Filters and use OnActionExecuting filter and handle the validation there (haven't used that myself tho).
Here is how to do it:
How can I centralize modelstate validation in asp.net mvc using action filters?
That way your method would never be called if any of the parameters were missing.
The model annotations with [Required] [Length] and all these attributes is one of the most common ways to validate your model, specially it integrates with the Razor View engine and generates JavaScript validation as well, the same will happen if you are using EntityFramework for your back end, so this way you will have validation at the level of the UI, Controller and Data access.
You can also use Code Contracts which allows you to put pre and post conditions for your method in a nice way https://msdn.microsoft.com/en-us/library/dd264808(v=vs.110).aspx
If none of the above is still not enough, then you can add some checks in either your controller action or in your business domain service to make some business validation and return an error code if any errors found
I have a method marked with Spring's #RequestMapping that includes an HttpServletRequest method parameter.
If I print out the results of a call to "request.getServletPath()" when the path is, say, "/things/{thingId}", I will get "/things/2489sdfjk43298f," where the {thingId} path parameter has been replaced with the actual value.
I want to print out the literal request path "/things/{thingId}"; I.e. with the curly-braced, un-replaced path parameter "{thingId}."
Is this possible in any way?
Edit: After looking at Sotirios's second comment below, I realize I may be looking at the problem backward. Here's what I'm actually trying to do...
I am trying to making a single endpoint under "/**" that gets the path from the HttpServletRequest, which I use to look up a value in an enum. This enum has several fields, one of which is obviously the aforementioned path, but another is the path of a target JSP file. I then put this path into a ModelAndView object and return it to display the page.
This was going just fine until I hit the first endpoint with a path parameter, because I obviously can't place the value "/things/2489sdfjk43298f" into the enum, because that will only match for that one specific thing with that one specific ID.
So perhaps the actual question would be: How would I do that look-up when parts of the path will change due to path parameters? Is there some sort of wildcard-containing String format I can use?
I guess this is turning into more of a enum-lookup/String-matching question. My bad.
Edit 2: Shortened example of the enum thing I'm talking about:
public enum JspEndpointType {
HOME("/home", "jsp/home");
private static final Map<String, String> pathMap;
private String requestPath;
private String jspPath;
static {
pathMap = new HashMap<>();
for (JspEndpointType jspEndpointType : JspEndpointType.values()) {
pathMap.put(jspEndpointType.getRequestPath(), jspEndpointType.getJspPath());
}
}
private JspEndpointValue(String requestPath, String jspPath) {
this.requestPath = requestPath;
this.jspPath = jspPath;
}
public String getRequestPath() {
return requestPath;
}
public String getJspPath() {
return jspPath;
}
public static String getByRequestPath(String requestPath) {
return pathMap.get(requestPath);
}
}
Shortened example of my endpoint:
#RequestMapping(value = "/**", method = RequestMethod.GET)
public ModelAndView showPage(HttpServletRequest request) {
return new ModelAndView(JspEndpointType.getByRequestPath(request.getServletPath()));
}
So things essentially boil down to trying to add to the enum a value like this:
THINGS("/things/{thingId}", "jsp/things/whatever")
..and then being able to pass in the path "/things/2489sdfjk43298f" and get back "/jsp/things/whatever."
Edit 3: I found this StackoverFlow question which directed me to Spring's UriComponentsBuilder, specifically the "fromPath" method. However, that seems to be the reverse of what I'm trying to do...
You may look for the #RequestMapping annotation on your own, using reflection.
I was wondering if it's possible to use an extension method with asp.net webforms and nvelocity. I would like to set some defaults if the string value is null or empty.
Example of .vm file:
Example of my email body...
Billable Status: $billableStatus.Evaluate()
rest of my email body...
Attempted extension method:
public static class Helper
{
public static string Evaluate(this string value)
{
if (String.IsNullOrEmpty(value))
return "Not Provided";
else
return value;
}
}
Or is there an alternative to what I'm tryting to accomplish?
I don't think NVelocity can resolve extension methods with C#/VB.NET syntax sugar. What I do is register an instance of a helper in the velocity context:
var context = VelocityContext();
context.Put("helper", new Helper());
context.Put("billableStatus", "something");
...
and then in your template:
$helper.Evaluate($billableStatus)
You have to make your helper non-static for this to work, of course.
I came across something similar in past and I was looking for something more sophisticated and with more control. I found that NVelocity does provide a way to intercept the method and property calls but for that you will have to implement certain things. In order to make your custom interceptor you will need to implement NVelocity.IDuck. For example
public class MyClass : NVelocity.IDuck
{
public object GetInvoke(string propName)
{
....
}
public object Invoke(string method, params object[] args)
{
....
}
public void SetInvoke(string propName, object value)
{
....
}
}
Now any instance of MyClass will intercept and pass the method and property calls to our these three function implementation and give us a chance to resolve and return the output. You may notice from these three function signatures that in order to implement them we may need some reflection where we can locate respective methods on available extension types and execute them. If needed you can read following blog post for more details about going this way. NVelocity and extension methods
I don't know if this is the right way of doing this or not, but I am using Jquery and MVC2. I am using a the $.ajax method to make a call back to a controller to do some business logic on a .blur of a textbox.
I have two views that basically do the same thing with the common data, but are using different models. They both use the same controller. It might be easier to explain with code:
So here are the two models:
public class RecordModel {
public string RecordID { get; set; }
public string OtherProperties { get; set; }
}
public class SecondaryModel {
public string RecordID { get; set; }
public string OtherPropertiesDifferentThanOtherModel { get; set; }
}
There are two views that are strongly typed to these models. One is RecordModel, the other SecondaryModel.
Now on these views is a input="text" that is created via:
<%= Html.TextBoxFor(model => model.RecordID) %>
There is jQuery javascript that binds the .blur method to a call:
<script>
$('#RecordID').blur(function() {
var data = new Object();
data.RecordID = $('#RecordID').val();
// Any other stuff needed
$.ajax({
url: '/Controller/ValidateRecordID',
type: 'post',
dataType: 'json',
data: data,
success: function(result) {
alert('success: ' + result);
},
error: function(result) {
alert('failed');
}
});
}
</script>
The controller looks like:
[HttpPost]
public ActionResult ValidateRecordID(RecordModel model) {
// TODO: Do some verification code here
return this.Json("Validated.");
}
Now this works fine if I explicitly name the RecordModel in the controller for the View that uses the RecordModel. However, the SecondaryModel view also tries to call this function, and it fails because it's expecting the RecordModel and not the SecondaryModel.
So my question is this. How can two different strongly typed views use the same Action in a controller and still adhering to the modeling pattern? I've tried abstract classes and interfaces (and changing the view pages to use the Interface/abstract class) and it still fails.
Any help? And sorry for the robustness of the post...
Thanks.
You could define an interface for those classes.
interface IRecord
{
string RecordID { get; set; }
string OtherProperties { get; set; }
}
and make the method receive the model by using that:
[HttpPost]
public ActionResult ValidateRecordID(IRecord model)
{
// TODO: Do some verification code here
return this.Json("Validated.");
}
If you only need the RecordID, you can just have the controller method take int RecordID and it will pull that out of the form post data instead of building the view model back up and providing that to your action method.
[HttpPost]
public ActionResult ValidateRecordID(int RecordID) {
// TODO: Do some verification code here
return this.Json("Validated.");
}
There is no direct way of binding data to a interface/abstract class. The DefaultModelBinder will try to instantiate that type, which is (by definition) impossible.
So, IMHO, you should not use that option. And if you still want to share the same controller action between the two views, the usual way of doing that would be using a ViewModel.
Make your strongly-typed views reference that viewmodel. Make the single shared action receive an instance of it. Inside the action, you will decide which "real" model should be used...
If you need some parameter in order to distinguish where the post came from (view 1 or 2), just add that parameter to the ajax call URL.
Of course, another way is keeping what you have already tried (interface/abstract class), but you'll need a custom Model Binder in that case... Sounds like overcoding to me, but it's your choice.
Edit After my dear SO fellow #Charles Boyung made a gracious (and wrong) comment below, I've come to the conclusion that my answer was not exactly accurate. So I have fixed some of the terminology that I've used here - hope it is clearer now.
In the case above your action could accept two strings instead of a concrete type.
Another possibility is having two actions. Each action taking one of your types. I'm assuming that functionality each type is basically the same. Once the values have been extracted hand them off to a method. In your case method will probably be the same for each action.
public ActionResult Method1(Record record)
{
ProcessAction(record.id, record.Property);
}
public ActionResult Action2(OtherRecord record)
{
ProcessAction(record.id, record.OtherProperty);
}
private void ProcessAction(string id, string otherproperity)
{
//make happen
}
ASP.NET MVC 2.0 will now, by default, throw an exception when an action attempts to return JSON in response to a GET request. I know this can be overridden on a method by method basis by using JsonRequestBehavior.AllowGet, but is it possible to set on a controller or higher basis (possibly the web.config)?
Update: Per Levi's comment, this is what I ended up using-
protected override JsonResult Json(object data, string contentType, System.Text.Encoding contentEncoding)
{
return Json(data, contentType, JsonRequestBehavior.AllowGet);
}
This, like other MVC-specific settings, is not settable via Web.config. But you have two options:
Override the Controller.Json(object, string, Encoding) overload to call Json(object, string, Encoding, JsonRequestBehavior), passing JsonRequestBehavior.AllowGet as the last argument. If you want this to apply to all controllers, then do this inside an abstract base controller class, then have all your controllers subclass that abstract class.
Make an extension method MyJson(this Controller, ...) which creates a JsonResult and sets the appropriate properties, then call it from your controller via this.MyJson(...).
There's another option. Use Action Filters.
Create a new ActionFilterAttribute, apply it to your controller or a specific action (depending on your needs). This should suffice:
public class JsonRequestBehaviorAttribute : ActionFilterAttribute
{
private JsonRequestBehavior Behavior { get; set; }
public JsonRequestBehaviorAttribute()
{
Behavior = JsonRequestBehavior.AllowGet;
}
public override void OnResultExecuting(ResultExecutingContext filterContext)
{
var result = filterContext.Result as JsonResult;
if (result != null)
{
result.JsonRequestBehavior = Behavior;
}
}
}
Then apply it like this:
[JsonRequestBehavior]
public class Upload2Controller : Controller
MVC 2 block Json for GET requests for security reasons. If you want to override that behavior, check out the overload for Json that accepts a JsonRequestBehavior parameter.
public ActionResult Index()
{
return Json(data, JsonRequestBehavior.AllowGet)
}
I also got this error when I first use MVC 2.0 using my old code in MVC 1.0. I use fiddler to identify the cause of the error. See the steps on how to troubleshoot it using Fidder -
http://www.rodcerrada.com/post/2011/07/11/jQuery-getJSON()-does-not-tirgger-the-callback-in-ASPNET-MVC-2.aspx
Is this is the security issue MVC2 was trying to address?
http://haacked.com/archive/2009/06/25/json-hijacking.aspx
If so, it seems like the vulnerability is only an issue if you are trying to do a json call to an outside website. If your MVC2 app is only making json calls to your own website (to fill jqgrids for example), shouldn't you be able to safely override the Json call in your base controller to always allow get?
Just change JSON code from :
$.getJson("methodname/" + ID, null, function (data, textStatus)
to:
$.post("methodname/" + ID, null, function (data, textStatus)