I have server side code written which is including navigational property for many to many relation ship as shown below.
var result = _contextProvider.Context.ResourceProperty.Include("AssociatedStandardResourceProperty.AssociatedLists").Where(t => t.ResourceId == resId);
//Return matching resource properties
return result;
However, when i am trying to retrieve data from breeze datacontext i am getting query execution error as shown below.
var getResourceProperties = function (resourceId, resourcePropertyObservable) {
var query = EntityQuery.from('GetResourceProperties')
.withParameters({ resourceId: resourceId })
.expand("AssociatedStandardResourceProperty.AssociatedLists");
return manager.executeQuery(query)
.then(querySucceeded)
.fail(queryFailed);
function querySucceeded(data) {
if (resourcePropertyObservable) {
resourcePropertyObservable(data.results);
}
log('Retrieved listObservable from remote data source',
data, true);
}
};
Query is failing and all data is retreived in log message i have written in queryFailed function.
I have also checked by removing expand at client side and also removing include at server side and then including expand at client side.
Please let me know how i can make it work.
Thanks
I have observed that problem was due to many to many mapping between two entities . After removing the relationship we are able to retrieve associatedEntities data
Just a guess here, but if you are performing the include on the server, then you don't need the expand on the client and vice versa. Your example seems to be doing both. What is the error message that you are getting?
Related
I am a new user to JavaScript and the meteor framework trying to understand the basic concepts. First of all I want to add a single document to a collection without duplicate entries.
this.addRole = function(roleName){
console.log(MongoRoles.find({name: roleName}).count());
if(!MongoRoles.find({name: roleName}).count())
MongoRoles.insert({name: roleName});
}
This code is called on the server as well as on the client. The log message on the client tells me there are no entries in the collection. Even if I refresh the page several times.
On the server duplicate entries get entered into the collection. I don't know why. Probably I did not understand the key concept. Could someone point it out to me, please?
Edit-1:
No, autopublish and insecure are not installed anymore. But I already published the MongoRoles collection (server side) and subscribed to it (client side). Furthermore I created a allow rule for inserts (client side).
Edit-2:
Thanks a lot for showing me the meteor method way but I want to get the point doing it without server side only methods involved. Let us say for academic purposes. ;-)
Just wrote a small example:
Client:
Posts = new Mongo.Collection("posts");
Posts.insert({title: "title-1"});
console.log(Posts.find().count());
Server:
Posts = new Mongo.Collection("posts");
Meteor.publish(null, function () {
return Posts.find()
})
Posts.allow({
insert: function(){return true}
})
If I check the server database via 'meteor mongo' it tells me every insert of my client code is saved there.
The log on the client tells me '1 count' every time I refresh the page. But I expected both the same. What am I doing wrong?
Edit-3:
I am back on my original role example (sorry for that). Just thought I got the point but I am still clueless. If I check the variable 'roleCount', 0 is responded all the time. How can I load the correct value into my variable? What is the best way to check if a document exists before the insertion into a collection? Guess the .find() is asynchronous as well? If so, how can I do it synchronous? If I got it right I have to wait for the value (synchronous) because I really relay on it.
Shared environment (client and server):
Roles = new Mongo.Collection("jaqua_roles");
Roles.allow({
insert: function(){return true}
})
var Role = function(){
this.addRole = function(roleName){
var roleCount = Roles.find({name: roleName}).count();
console.log(roleCount);
if(roleCount === 0){
Roles.insert({name: roleName}, function(error, result){
try{
console.log("Success: " + result);
var roleCount = Roles.find({name: roleName}).count();
console.log(roleCount);
} catch(error){
}
});
}
};
this.deleteRole = function(){
};
}
role = new Role();
role.addRole('test-role');
Server only:
Meteor.publish(null, function () {
return Roles.find()
})
Meteor's insert/update/remove methods (client-side) are not a great idea to use. Too many potential security pitfalls, and it takes a lot of thought and time to really patch up any holes. Further reading here.
I'm also wondering where you're calling addRole from. Assuming it's being triggered from client-side only, I would do this:
Client-side Code:
this.addRole = function(roleName){
var roleCount = MongoRoles.find({name: roleName}).count();
console.log(roleCount);
if (roleCount === 0) {
Meteor.call('insertRole', roleName, function (error, result) {
if (error) {
// check error.error and error.reason (if I'm remembering right)
} else {
// Success!
}
});
}
}
How I've modified this code and why:
I made a roleCount variable so that you can avoid calling MongoRoles.find() twice like that, which is inefficient and consumes unneeded resources (CPU, disk I/O, etc). Store it once, then reference the variable instead, much better.
When checking numbers, try to avoid doing things like if (!count). Using if (count === 0) is clearer, and shows that you're referencing a number. Statements like if (!xyz) would make one think this is a boolean (true/false) value.
Always use === in JavaScript, unless you want to intentionally do a loose equality operation. Read more on this.
Always use open/closed curly braces for if and other blocks, even if it contains just a single line of code. This is just good practice so that if you decide to add another line later, you don't have to then wrap it in braces. Just a good practice thing.
Changed your database insert into a Meteor method (see below).
Side note: I've used JavaScript (ES5), but since you're new to JavaScript, I think you should jump right into ES6. ES is short for ECMAScript (which is what JS is based on). ES6 (or ECMAScript 2015) is the most recent stable version which includes all kinds of new awesomeness that JavaScript didn't previously have.
Server-side Code:
Meteor.method('insertRole', function (roleName) {
check(roleName, String);
try {
// Any security checks, such as logged-in user, validating roleName, etc
MongoRoles.insert({name: roleName});
} catch (error) {
// error handling. just throw an error from here and handle it on client
if (badThing) {
throw new Meteor.Error('bad-thing', 'A bad thing happened.');
}
}
});
Hope this helps. This is all off the top of my head with no testing at all. But it should give you a better idea of an improved structure when it comes to database operations.
Addressing your edits
Your code looks good, except a couple issues:
You're defining Posts twice, don't do that. Make a file, for example, /lib/collections/posts.js and put the declaration and instantiation of Mongo.Collection in there. Then it will be executed on both client and server.
Your console.log would probably return an error, or zero, because Posts.insert is asynchronous on the client side. Try the below instead:
.
Posts.insert({title: "title-1"}, function (error, result) {
console.log(Posts.find().count());
});
I was using Breeze v1.1.2 that came with the Hot Towel template which has now been extended to form my project. I made the mistake of updating the NuGet package to the current 1.3.3 (I never learn). Anyway, all was well, and now not so much!
I followed the instructions in the release notes and other docs to change my BreezeWebApiConfig file to:
[assembly: WebActivator.PreApplicationStartMethod(
typeof(BreezeWebApiConfig), "RegisterBreezePreStart")]
namespace MyApp.App_Start {
public static class BreezeWebApiConfig {
public static void RegisterBreezePreStart() {
GlobalConfiguration.Configuration.Routes.MapHttpRoute(
name: "BreezeApi",
routeTemplate: "breeze/{controller}/{action}"
);}}}
And the config.js file (which provides the serviceName to the EntityManager constructor) to:
var remoteServiceName = 'breeze/breeze'; // NEW version
//var remoteServiceName = 'api/breeze'; // OLD version
And my BreezeController if you're interested:
[BreezeController]
public class BreezeController : ApiController
{
readonly EFContextProvider<MyDbContext> _contextProvider =
new EFContextProvider<MyDbContext>();
[HttpGet]
public string Metadata()
{
return _contextProvider.Metadata();
}
[HttpGet]
public IQueryable<SomeItem> SomeItems()
{
// Do stuff here...
}
}
Now I get the "cannot execute _executeQueryCore until metadataStore is populated" error.
What am I missing here?
EDIT:
I perhaps left out the part you needed... Above in the SomeItems() method, the stuff that actually gets done is a call to the GetMeSomeData() method in the MyDBContext class. This method makes the following call to a stored procedure to get the data.
public virtual ObjectResult<SomeItem> GetMeSomeData(string inParam)
{
var p = new object[] { new SqlParameter("#inParam", inParam) };
var retVal = ((IObjectContextAdapter)this).ObjectContext.ExecuteStoreQuery<SomeItem>("exec GetData #SN", p);
return retVal;
}
Now given my limited understanding, the call to Metadata() is not failing, but I don't think it has any idea what the entity model is when coming back, even though somewhere along the line, it should figure that out from the entity model I do have (i.e. SomeItem)? The return string from Metadata() doesn't have any information about the entity. Is there a way to make it aware? Or am I just completely off in left field playing with the daisies?
Hard to say based on this report. Let's see if Breeze is right.
Open the browser debugging tools and look at the network traffic. Do you see an attempt to get metadata from the server before you get that error? If so, did it succeed? Or 404? Or 500? What was the error?
I'm betting it didn't even try. If it didn't, the usual reason is that you tried some Breeze operation before your first query ... and you didn't ask for metadata explicitly either. Did you try to create an entity? That requires metadata.
The point is, you've got to track down the Breeze operation that precipitates the error. Sure everything should just work. The world should be rainbows and unicorns. When it isn't, we heave a sigh, break out the debugger, and start with the information that the error gave us.
And for the rest of you out there ... upgrading to a new Breeze version is a good thing.
Happy coding everyone.
Follow-up to your update
Breeze doesn't know how you get your data on the back-end. If the query result has a recognizable entity in it, Breeze will cache that. It's still up to you in the query callback to ensure that what you deliver to the caller is something meaningful.
You say that you're server-side metadata method doesn't have any idea what SomeItem is? Then it's not much use to the client. If it returns a null string, Breeze may treat that as "no metadata at all" in which case you should be getting the "cannot execute _executeQueryCore until metadataStore is populated" error message. Btw, did you check the network traffic to determine what your server actually returned in response to the metadata request (or if there was such a request)?
There are many ways to create Metadata on the server. The easiest is to use EF ... at least as a modeling tool at design time. What's in that MyDbContext of yours? Why isn't SomeItem in there?
You also can create metadata on the client if you don't want to generate it from the server. You do have to tell the Breeze client that you've made that choice. Much of this is explained in the documentation "Metadata Format".
I get the feeling that you're kind of winging it. You want to stray from the happy path ... and that's cool. But most of us need to learn to walk before we run.
My question is this: How can you implement a default server-side "filter" for a navigation property?
In our application we seldom actually delete anything from the database. Instead, we implement "soft deletes" where each table has a Deleted bit column. If this column is true the record has been "deleted". If it is false, it has not.
This allows us to easily "undelete" records accidentally deleted by the client.
Our current ASP.NET Web API returns only "undeleted" records by default, unless a deleted argument is sent as true from the client. The idea is that the consumer of the service doesn't have to worry about specifying that they only want undeleted items.
Implementing this same functionality in Breeze is quite simple, at least for base entities. For example, here would be the implementation of the classic Todo's example, adding a "Deleted" bit field:
// Note: Will show only undeleted items by default unless you explicitly pass deleted = true.
[HttpGet]
public IQueryable<BreezeSampleTodoItem> Todos(bool deleted = false) {
return _contextProvider.Context.Todos.Where(td => td.Deleted == deleted);
}
On the client, all we need to do is...
var query = breeze.EntityQuery.from("Todos");
...to get all undeleted Todos, or...
var query = breeze.EntityQuery.from("Todos").withParameters({deleted: true})
...to get all deleted Todos.
But let's say that a BreezeSampleTodoItem has a child collection for the tools that are needed to complete that Todo. We'll call this "Tools". Tools also implements soft deletes. When we perform a query that uses expand to get a Todo with its Tools, it will return all Tools - "deleted" or not.
But how can I filter out these records by default when Todo.Tools is expanded?
It has occurred to me to have separate Web API methods for each item that may need expanded, for example:
[HttpGet]
public IQueryable<Todo> TodoAndTools(bool deletedTodos = false, bool deletedTools = false)
{
return // ...Code to get filtered Todos with filtered Tools
}
I found some example code of how to do this in another SO post, but it requires hand-coding each property of Todo. The code from the above-mentioned post also returns a List, not an IQueryable. Furthermore this requires methods to be added for every possible expansion which isn't cool.
Essentially what I'm looking for is some way to define a piece of code that gets called whenever Todos is queried, and another for whenever Tools is queried - preferably being able to pass an argument that defines if it should return Deleted items. This could be anywhere on the server-side stack - be it in the Web API method, itself, or maybe part of Entity Framework (note that filtering Include extensions is not supported in EF.)
Breeze cannot do exactly what you are asking for right now, although we have discussed the idea of allowing the filtering of "expands", but we really need more feedback as to whether the community would find this useful. Please add this to the breeze User Voice and vote for it. We take these suggestions very seriously.
Moreover, as you point out, EF does not support this.
But... what you can do is use a projection instead of an expand to do something very similar:
public IQueryable<Object> TodoAndTools(bool deleted = false
,bool deletedTools = false) {
var baseQuery = _contextProvider.Context.Todos.Where(td => td.Deleted == deleted);
return baseQuery.Select(t => new {
Todo: t,
Tools: t.Tools.Where( tool => tool.Deleted = deletedTools);
});
}
Several things to note here:
1) We are returning an IQueryable of Object instead of IQueryable of ToDo
2) Breeze will inspect the returned payload and automatically create breeze entities for any 'entityTypes' returned (even within a projection). So the result of this query will be an array of javascript objects each with two properties; 'ToDo' and 'Tools' where Tools is an array of 'Tool' entities. The nice thing is that both ToDo and Tool entities returned within the projection will be 'full' breeze entities.
3) You can still pass client side filters based on the projected property names. i.e.
var query = EntityQuery.from("TodoAndTools")
.where("Todo.Description", "startsWith", "A")
.using(em);
4) EF does support this.
I am working with a database first model in Entity Framework 5 and when I attempt to add a row, I get the following error:
"No views were found in assemblies or could be generated for Table 'ui_renewals'."
The table exists in my EDMX and the template generated a ui_renewals class. I've deleted the table from the EDMX and added it again using the Update Model from Database option and I get the same error. Creating a separate connection for it resolves the issue, but that seems like a less-than-ideal solution (more like a kludge) not to mention it makes it more difficult to maintain in the future.
Any ideas on how to fix this so that I can add or update (I've tried both) a row in ui_renewals?
Here is the code I'm currently using - only difference before was using db as a DBContext instead of ui (yes, receipt is misspelled - gotta love legacy stuff)
[HttpPost]
public bool UpdateTeacher(string login_id, string password, UIRenewal data)
{
if (ModelState.IsValid)
{
// map from UIRenewal VM to ui_renewal
ui_renewals Renewal = Mapper.Map<UIRenewal, ui_renewals>(data);
// check to see if this is a new entry or not
var tmp = ui.ui_renewals.Find(Renewal.reciept);
if (tmp == null)
ui.ui_renewals.Add(Renewal);
else
{
// mark as modified
db.Entry(Renewal).State = EntityState.Modified;
}
// save it
try
{
ui.SaveChanges();
}
catch (DBConcurrencyException)
{
return false;
}
return true;
}
return false;
}
I should mention that I do have a view in the model (v_recent_license).
I know this is a very old question, however as I haven't found any other topics like this, I'll post my answer.
I have had the same Exception thrown. I found that, in a failed attempt to optimize EF performance, following the advices found here, I left behind this piece of code in EF .edmx code-behind:
<EntityContainerMapping StorageEntityContainer="XXXModelStoreContainer" CdmEntityContainer="YYYEntities" GenerateUpdateViews="false">
I removed the GenerateUpdateViews="false" string, and all is working again.
(The Exception message is a little misleading in my opinion).
I've been looking on forums for 2 days now and can't find a good answer so I'll just post it.
I appear to be having a problem posting JSON back to the controller to save. The JSON should map to model view but it keeps getting default(constructor)values rather then the values from the POST.
We have a series of JS widgets that contain a data field with json in them. We do all our data manipulation in these widget objects on the client side. When a user wants to save we grab the data we need from the widgets involved and we put it into another JSON object that matches a ViewModel and POST that back to the server.
For example:
$("#Save").click(function () {
if (itemDetails.preparedForSubmit() && itemConnections.preparedForSubmit()) {
itemComposite.data.Details = itemDetails.data;
itemComposite.data.Connections= itemConnections.data;
$.post(MYURL, itemComposite.data);
} else {
alert("failed to save");
}
});
The preparedForSubmit() method simple does stuff like any validation checks or last minute formatting you might need to do client side.
The itemDetails widgets data matches a ViewModel.
The itemConnections widgets data matches a collection of ViewModels.
The Controller looks like this:
[HttpPost]
virtual public JsonResult SaveItemDetailsComposite(ItemComposite inItemData)
{
if (ModelState.IsValid)
{
try
{
_Mapper.Save(itemComposite.Details , itemComposite.Connections);
return Json(true);
}
catch (Exception ex)
{
_log.Error("Exception " + ex.InnerException.Message);
throw;
}
}
return Json(SiteMasterUtilities.CreateValidationErrorResponse(ModelState));
}
The ItemComposite Class is a simple View Model that contains a single itemDetails object and a collection of itemConnections. When it returns data to here it is just getting the default data as if it got a new ItemComposite rather than converting the POST data.
in Firebug I see the data is posted. Although it looks weird not automatically formatted in firebug.
Are you saying that itemComposite.data is formatted as a JSON object? If so, I'm pretty sure you're going to have to de-serialize it before you can cast it to your object. Something like:
ItemComposite ic = jsSerializer.Deserialize<ItemComposite>(this.HttpContext.Request.Params[0]);
You may want to look into a framework like JSON.NET to ensure that your data is being serialized properly when it gets supplied to your Action.
JSON.NET seems like it's one of the main stream frameworks: http://json.codeplex.com/releases/view/43775
Hope this helps.
Cory
You could also use the JSON Serializer in WCF: http://msdn.microsoft.com/en-us/library/system.runtime.serialization.json.datacontractjsonserializer.aspx
SO wouldn't let me put both links in one answer, sorry for the split answer.
Thanks everyone. I think I have solved my problem and I'm pretty sure that I had four issues. For the most part I followed thatSteveguys's suggestion and read more on this article: http://haacked.com/archive/2010/04/15/sending-json-to-an-asp-net-mvc-action-method-argument.aspx
Using jQuery's post() method and specifying json as the type didn't seem to actually send it as json. By using the ajax() method and specifying json it sent it as json.
The JSON.serialize() method was also need to cleanly send over the json.
Also my ViewModel design was a big problem. We are using the MS code analytic build junk and it didn't want me having a setter for my collections in the ViewModel. So me being from a java/hibernate world, thought it didn't need them to bind and it would just come in as a serialized object magically. Once I just suppressed the error and reset up my setters. I am getting the collections now in my controller.
I believe using the MVC2 Future's Value Providers are doing something but it still doesn't convert json dates robustly, So I am still investigating the best way to do that.
I hope my issues help out others.
UPDATE: using this method to update collections of data appears to be super slow. A collection with 200 entries in it and 8 fields per entry takes 3 minutes to get to the controller. Just 1 or 2 entries take very little time. The only thing I know of that is happening between here is data binding to the model view. I don't know if MVC2 provides a easy way to send this much data and bind it.