Somehow I have gotten sideways with my Grails MVC mapping and I do not understand how.
I have a controller, AController, which I generated using the Grails command line wizard. At a later date I generated a view for that controller to customize the view.
AController is in [project]/grails-app/controllers/[package]/AController.groovy and the view .gsp's are in [project]/grails-app/views/A/.
The URLMappings.groovy has:
"/$controller/$action?/$id?"{
constraints {
// apply constraints here
}
}
When I run the application and enter a url of the form: localhost:8080/[project]/A/list I reach, as expected, the method A.list in AController.groovy.
However, when I then return from A.list expecting the framework to route to list.gsp in [project]grails-app/views/A/ I see a 500 error with the message:
"URL mapping must either provide a controller or view name to map to!"
Obviously I am doing something stupid but I cannot see what it was that I broke. URLMappings.groovy looks correct. File locations look correct. Scaffolding seems properly customized.
Any suggestions?
Du-Oh
The problem was that there was no .count for an array. For some reason my brain insists on .count and not .size(). Stupid human error.
Related
I have a weird error going on where when I start my Grails application and see the default home page, no matter what controller I click on I get a 404 not found. But if I change my URL mappings file to point a particular controller and method, then the associated view is rendered fine. I tried typing the url as 'controller/method' but that also gave the 404 and I know that the methods aren't being executed because my test log statements don't print. The only way my views are coming up is if I force them using the URL mappings file and then the test log statements in the methods will also print.
Make sure you have a URL mapping defined which supports the controller/action pattern.
class UrlMappings {
static mappings = {
// you probably want a mapping like this...
"/$controller/$action?/$id?(.$format)?"{
}
// other mappings here
}
}
I have created several controllers in my Grails project and put data for each controller in the bootstrap, but the data does not appear in the table for each controller that scaffold provides as the default view. I have checked inside dbconsole to be certain that the data is there, which it is. I have also refreshed the dependencies to make certain that the version of the scaffolding plugin is not corrupted. I am using Grails 2.3.5 and Scaffolding 2.0.1.Are there any suggestions of what could be wrong?
class DepartmentController {
static scaffold=Department
def index() { }
}
Looking back at other examples of using scaffolding I realize now that I should have taken out the index portion of the code, even though it is empty.
Remove your the index method and make it like this:
class DepartmentController {
static scaffold=Department
}
Put some log messages into the controllers (or debug the app) right after the controller loads the data using the domain class in order to see if the query has resulted in any domain instances.
If not, activate sql logging and check the exact select statement executed. Possibly you have something wrong in your domain mapping so a wrong select stmt is sent to the db
I'm kind of new to grails and I'm trying to just map a basic URL request to a view.
So, say I have a view, /x/index.gsp and I want the user to be able to go to it. There will also be /y/index.gsp, /z/index.gsp, etc.
I defined it like so:
"/$customer/index" { view = {params.customer+"/index"} }
This seems to throw an exception though. I also have :
"/$customer/$controller/$action?/$id?" { }
which does work and I don't want to have to create a controller that doesn't really do anything but handle the index call and show it.
I'm sure I'm missing something simple but I don't know what it is.
The reason the first mapping fails is because it can't figure out what controller to route the request to.
To fix it, you need to define what controller you want the top mapping to route to. This is how I did this in a recent project of mine:
"/uploaders/$id" {
controller: "uploader"
}
To map to just a view:
"/$customer/index"(view: "/${params.customer}/index")
In my /Views/Shared/ folder I created an EntityNotFound.cshtml razor view. In one of my controller actions I have the following call:
return View(MVC.Shared.Views.EntityNotFound, "Company");
This causes the following exception:
System.InvalidOperationException: The view '~/Views/Shared/EntityNotFound.cshtml' or its master was not found or no view engine supports the searched locations. The following locations were searched:
~/Views/Company/Company.cshtml
~/Views/Company/Company.vbhtml
~/Views/Shared/Company.cshtml
~/Views/Shared/Company.vbhtml
I am confused, because it does not even seem to be attempting to search ~/Views/Shared/EntityNotFound.cshtml. Even if I replace MVC.Shared.Views.EntityNotFound with "EntityNotFound" I get the same error.
Why is Asp.Net MVC not even attempting to find my shared view?
Have a look at the list of overloads for View();
http://msdn.microsoft.com/en-us/library/system.web.mvc.controller.view.aspx
Specifically, when you pass View(string,string); it sees the second string as the name of the master view.
Whats probably happening, is that it can't find the "Company" master view, you'll not the exception messages says
... or its master was not found...
Which means that it is probably finding the NotFoundException.cshtml, but can't correctly find the Company.cshtml that it's looking for as the master.
The correct syntax should be this (don't pass path, MVC is a language by conventions)
return View("EntityNotFound");
Assuming "Company" is a param you wnat to pass to the view, try like this:
ViewBag.ErrorEntity = "Company";
return View("EntityNotFound");
And from the View
<p>Entity not found: #ViewBag.ErrorEntity</p>
I'm new to Grails and am trying to build a CMS with it.
I want the navigation menu to read from the database so a new page will automatically get a link in the navigation. I've been reading Grails: use controller from index.gsp and related questions, but the answers don't seem to work for me. :(
I've created a domain class named Navigation and a template called _header.
In the "Navigation/list" namespace everything works fine, but outside I can't get to the Navigation data.
I've setup url mapping like so:
class UrlMappings {
static mappings = {
"/$controller/$action?/$id?"{
constraints {
// apply constraints here
}
}
"/"(controller : "Navigation", action : "list")
"/"(view:"/index")
"500"(view:'/error')
}
}
But that doesn't seem to work. Any clues on what could be the problem?
You have two mappings for "/", your new one and the original one: "/"(view:"/index") - for starters you'll need to remove the other one.
Not sure if you are aware of this, but there is an open source CMS built in Grails called Weceem. If you need to use it as part of another Grails application, there is also a grails plug in for Weceem, so you can use it as part of your app.
It might worth looking into it before building a complete new CMS :-)
I was looking at the problem all wrong, urlmapping only made the index.gsp redirect to navigation/list. What I was looking for was the
DomainClass.findAll( String query )
propertie to use in the g:each tag
<g:each in="${Navigation.findAll('from Navigation as n where n.css=?', ['ctBoven'])}" var="oNavigation" status="i">
This allows me to read any database from any page.