i want to compare through 2 information, one is user input and second is admin ID in database. in my project, i'm using WCF Ria. i did created one auto-generated Domain Service Class and the code to retrieve everything in tblAdmin was auto-generated. i load the data in this way ::
var context = new OrganizationContext();
var x = context.tblAdmins;
context.Load(context.GetTblAdminsQuery());
cb1.ItemsSource = x;
it can load in this way, but i cannot get the x.adminID with this. so i tried this ::
foreach (var admin in x)
{
cb1.Items.Add(admin.adminID);
}
but failed... may i know is that possible to dig through the data without foreach or is there something wrong in my code ??
Looks like the problem is that the context.Load call is asynchronous - to get the result you need to pass a callback and get your data there:
context.Load(context.GetTblAdminsQuery(), LoadCompleted, null);
and:
public void LoadCompleted(LoadOperation<YOUR_ENTITY_TYPE> op)
{
foreach(var item in op.Entities)
{
//item is your entity, you can get item.adminID
}
}
Related
I have posted question regarding firebase two days ago:
Android Firebase - add authenticated user into database
I got help that I needed and that solved first problem. But now I have a new problem. I was googling for quite some time, there are some posts about this issue but nothing solved my problem. I din't want to spam the previous question so I posted a new one.
When I try reading inserted data from the firebase database I get this error:
Newtonsoft.Json.JsonSerializationException: Error converting value
"test#user.com" to type 'carServiceApp.My_Classes.Account'. Path
'email', line 1, position 24.
Here is the code:
private async Task LoadData()
{
FirebaseUser users = FirebaseAuth.GetInstance(loginActivity.app).CurrentUser;
id = users.Uid;
var firebase = new FirebaseClient(loginActivity.FirebaseURL);
var items = await firebase.Child("users").Child(id).OnceAsync<Account>();
foreach (var item in items)
{
Account user = new Account();
user.uid = item.Object.uid;
user.name = item.Object.name;
user.lastName = item.Object.lastName;
user.phone = item.Object.phone;
user.email = item.Object.email;
userInput_ime.Text = user.name;
userInput_prezime.Text = user.lastName;
userInput_broj.Text = user.phone;
userInput_email.Text = user.email;
}
}
This is firebase data:
-users
-jwAP2dYNzJeiF3QlmEIEQoruUkO2
email: "test#user.com"
lastName: "user"
name: "test"
phone: "12421"
uid: "jwAP2dYNzJeiF3QlmEIEQoruUkO2"
Interesting thing is that when I try reading data with this:
var items = await firebase.Child("users").OnceAsync<Account>();
This works fine (I get last inserted user) . But when I add 'uid' node, then I get error. I was trying to solve this for quite some time but I just can't figure it out. I guess that there is no problem with the account class because it works in the case without uid node but doesn't work when another child() method is added.
Other information (Account class code and the way of storing that data into the database) you can see in the link at the top.
Note: I tried adding constructor in Account class but that doesn't help.
Ok, so I didn't exactly find a solution for this problem nor do I really understand why was this happening but I have found a workaround. I believe it's not ideal solution and that it does not fix existing problem. Or maybe it was problem with me not understanding firebase logic but here is what I came up with.
So, considering that it was all working fine if I didn't specify that uid node it was obvious there was some problem with class and data in firebase, matching problem I guess. Anyway, I decided to have that last uid node so I can have specific user selected and also to have the same data in firebase as it was in case where it was all working. So, this is how I have inserted data into firebase:
var item = firebase.Child("users").Child(id).PostAsync<Account>(user);
This created users node and child node. And PostAsync method created one more node with random key.
So when I tried reading with this:
var data = await firebase.Child("users").Child(id).OnceAsync<Account>();
It worked without problem. Now firebase data looks like this:
users
JPKdQbwcXbhBatZ2ihBNLRauhV83
-LCXyLpvdfQ448KOPKUp
email: "spider#man.com"
lastName: "man"
name: "spider"
phone: "14412"
uid: "JPKdQbwcXbhBatZ2ihBNLRauhV83"
There is a bit of redundancy, I basically have two ID's, but I don't understand how to create my class so I can get that data any other way so I made it this way. It works fine.
If anyone has better solution, I will gladly change it. Cheers
This was suppose to be a comment, but this is just suppose to be an addition for anyone that needs help with this issue.
I know that this answer has been out there for a while but this still seems to be a running structural quirk with Firebase and the usage of their rules. I ran into this issue with a complex structure that looked kind of like this
-Orders
-9876trfghji (User ID)
-0
BusnID: "ty890oihg"
Name: "Some Name"
AddOns: Object
ItemData: Object(containing other objects)
UserID: "9876trfghji"
Note: In this case as well as the case with cordas, you will see that both of the final objects has a UserID or uid.
I also was running into the issue of class de-serialization of the object without having the actual User ID in the objects data when it was being sent back to the device.
The reason that you have a “redundant” usage of the user id is for a security measure with the Firebase rules. The first UserID with the structure above you are able to control the access to the information based off of the users id without having to have an extra validation clause in the rules. Currently as of this post the the rule below would protect the data based on the User ID.
“Orders” : {
"$uid":{
".read":"auth != null",
".write":"auth.uid == $uid"
}
}
this allows the user with only the authorized user id to write content but anyone that has valid credentials can view the data.
The second User ID has to be placed in the object because without it you would not be able to do a standard cast to the object because your object would not have all of the data it would need to create the object. Regardless of if you are using a package like GoogleGson or Newtonsoft.Json the object still isn't full.
There is how ever a work around for this problem besides re-entering the User ID into the object. With the object that I have above I decided to just re-enter the User ID in my personal code to save the time and hassle of manual creation.
Using the Firebase.Database NuGet package you can manually create the object. Here is an example of the object in cordas problem
public static void GetUser_Firebase(User user, FirebaseApp app)
{
FirebaseDatabase database = FirebaseDatabase.GetInstance(app);
DatabaseReference reference = database.GetReference($"/users/{user.UserID}");
//"Using for getting firebase information", $"/users/{user.UserID}"
reference.AddListenerForSingleValueEvent(new UserInfo_DataValue());
}
class UserInfo_DataValue : Java.Lang.Object, IValueEventListener
{
private string ID;
public UserInfo_DataValue(string uid)
{
this.ID = uid;
}
public void OnCancelled(DatabaseError error)
{
//"Failed To Get User Information For User "
}
public void OnDataChange(DataSnapshot snapshot)
{
Dictionary<string, string> Map = new Dictionary<string, string>();
var items = snapshot.Children?.ToEnumerable<DataSnapshot>(); // using Linq
foreach(DataSnapshot item in items)
{
try
{
Map.Add(item.Key, item.Value.ToString()); // item.value is a Java.Lang.Object
}
catch(Exception ex)
{
//"EXCEPTION WITH DICTIONARY MAP"
}
}
User toReturn = new User();
toReturn.UserID this.ID;
foreach (var item in Map)
{
switch (item.Key)
{
case "email":
toReturn.email = item.Value;
break;
case "lastName":
toReturn.lastName = item.Value;
break;
case "name":
toReturn.name = item.Value;
break;
case "phone":
toReturn.phone = item.Value;
break;
}
}
}
}
Update
There is something that I would like to mention that I left out when I was writing this and that is the usage of Firebase.Database NuGet package with the Gson NuGet package and the Newtonsoft.Json Library
If you decide to use the FIrebase.Database library just know that you will be working very close with the Java.Lang and the Java.Util libraries. Objects like Java.Lang.Object can be very difficult and time consuming to write the code needed to de-serialize the data, but don't fear Gson is here!
The Gson package if you allow it can take a large load of work off of your hands for class de-serialization if you allow it. Gson is a library that will allow you to do Java.Lang.Obj to json string de-serialization. I know it seems weird, hand it an object get back a string sounds counter intuitive I know but just bear with me.
Here is an example of how to us the Gson Library with the object in cordas problem.
public static void Get_User(User user, FirebaseApp app)
{
FirebaseDatabase database = FirebaseDatabase.GetInstance(app);
DatabaseReference reference = database.GetReference($"Users/{user.UserID}");
reference.AddListenerForSingleValueEvent(new User_DataValue(user, app));
//$"Trying to make call for user orders Users/{user.UserID}");
}
class User_DataValue : Java.Lang.Object, IValueEventListener
{
private User User;
private FirebaseApp app;
public UserOrderID_Init_DataValue(User user, FirebaseApp app)
{
this.User = user;
this.app = app;
}
public void OnCancelled(DatabaseError error)
{
//$"Failed To Get User Orders {error.Message}");
}
public void OnDataChange(DataSnapshot snapshot)
{
//"Data received for user orders");
var gson = new GsonBuilder().SetPrettyPrinting().Create();
var json = gson.ToJson(snapshot.Value); // Gson extention method obj -> string
Formatted_Output("Data received for user order json ", json);
User user = JsonConvert.DeserializeObject<User>(json); //Newtonsoft.Json extention method string -> object
//now the user is a fully populated object with very little work
}
For anyone that might run into this in the future I hope that this helps
I'm coming from a SQL Server background, and experimenting with Redis in .NET using ServiceStack. I don't mean for Redis to be a full replacement for SQL Server, but I just wanted to get a basic idea of how to use it so I could see where we might make good use of it.
I'm struggling with what I think is a pretty basic issue. We have a list of items that are maintained in a couple of different data stores. For the sake of simplicity, assume the definition of the item is basic: an integer id and a string name. I'm trying to do the following:
Store an item
Retrieve an item if we only know its id
Overwrite an existing item if we only know its id
Show all the items for that specific type
And here's some of the code I've put together:
public class DocumentRepositoryRedis
{
private static string DOCUMENT_ID_KEY_BASE = "document::id::";
public IQueryable<Document> GetAllDocuments()
{
IEnumerable<Document> documentsFromRedis;
using (var documents = new RedisClient("localhost").As<Document>())
{
documentsFromRedis = documents.GetAll();
}
return documentsFromRedis.AsQueryable();
}
public Document GetDocument(int id)
{
Document document = null;
using (var redisDocuments = new RedisClient("localhost").As<Document>())
{
var documentKey = GetKeyByID(document.ID);
if (documentKey != null)
document = redisDocuments.GetValue(documentKey);
}
return document;
}
public void SaveDocument(Document document)
{
using (var redisDocuments = new RedisClient("localhost").As<Document>())
{
var documentKey = GetKeyByID(document.ID);
redisDocuments.SetEntry(documentKey, document);
}
}
private string GetKeyByID(int id)
{
return DOCUMENT_ID_KEY_BASE + id.ToString();
}
}
It all seems to work - except for GetAllDocuments. That's returning 0 documents, regardless of how many documents I have stored. What am I doing wrong?
The typed Redis client also gives you access to the non-typed methods - since Redis ultimately doesn't know or care about your object types. So when you use the client.SetEntry() method, it bypasses some of the typed client's features and just stores the object by a key. You'll want to use the client.Store method since it goes ahead and creates a SET in Redis with all the object IDs related to your type. This SET is important because it's what the GetAll method relies on to serve back all the objects to you. The client.Store method does infer the ID automatically so you'll want to play around with it.
You'd change your GetDocument(int id) and SaveDocument(Document document) methods to use the client.GetById(string id) method, and you'd use client.Store(T value) method. You won't need your GetKeyByID() method anymore. I believe your Document object will need an "Id" property for the typed client to infer your object ID.
I'm encountering a problem with one of my IEnumerable's that I haven't seen before.
I have a collection:
IEnumerable<IDependency> dependencies;
that's being used in a foreach loop.
foreach (var dependency in dependencies)
For some reason this foreach doesn't iterate over my IEnumerable and simply skips to the end.
If I change my foreach to loop through a a list however it seems to work fine:
foreach (var dependency in dependencies.ToList())
What could I be doing that's causing this behaviour? I haven't experienced this with IEnumerable before.
Update:
Here's the entire code of my foreach that's running in my method GenerateDotString:
foreach (var dependency in dependencies)
{
var dependentResource = dependency.Resource;
var lineColor = (dependency.Type == DependencyTypeEnum.DependencyType.Hard) ? "blue" : "red";
output += labelFormat.FormatWith(dependentResource.Name.MakeDotsafeString(), dependentResource.Name, dependentResource.ResourceType);
output += relationshipFormat.FormatWith(dependentResource.Name.MakeDotsafeString(), currentName, lineColor);
if (dependentResource.DependentResources != null)
{
output += GenerateDotString(dependentResource, dependentResource.DependentResources, searchDirection);
}
}
return output;
Update 2:
Here's the signature of the method containing this foreach (incase it helps).
private static string GenerateDotString(IResource resource, IEnumerable<IDependency> dependencies, SearchEnums.SearchDirection searchDirection)
Update 3:
Here's the method GetAllRelatedResourcesByParentGuidWithoutCacheCheck:
private IEnumerable<IDependency> GetAllRelatedResourcesByParentGuidWithoutCacheCheck(Guid parentCiGuid, Func<Guid, IEnumerable<IDependency>> getResources)
{
if (!_itemsCheckedForRelations.Contains(parentCiGuid)) // Have we already got related resources for this CI?;
{
var relatedResources = getResources(parentCiGuid);
_itemsCheckedForRelations.Add(parentCiGuid);
if (relatedResources.Count() > 0)
{
foreach (var relatedResource in relatedResources)
{
relatedResource.Resource.DependentResources = GetAllRelatedResourcesByParentGuidWithoutCacheCheck(relatedResource.Resource.Id, getResources);
yield return relatedResource;
}
}
}
}
Update 4:
I'm adding the methods in the chain here to be clear on how we're getting the collection of dependencies.
The above method GetAllRelatedResourcesByParentGuidWithoutCacheCheck accepts a delegate which in this case is:
private IEnumerable<IDependency> GetAllSupportsResources(Guid resourceId)
{
var hardDependents = GetSupportsHardByParentGuid(resourceId);
var softDependents = GetSupportsSoftByParentGuid(resourceId);
var allresources = hardDependents.Union(softDependents);
return allresources;
}
which is calling:
private IEnumerable<IDependency> GetSupportsHardByParentGuid(Guid parentCiGuid)
{
XmlNode ciXmlNode = _reportManagementService.RunReportWithParameters(Res.SupportsHardReportGuid, Res.DependentCiReportCiParamName + "=" + parentCiGuid);
return GetResourcesFromXmlNode(ciXmlNode, DependencyTypeEnum.DependencyType.Hard);
}
and returns:
private IEnumerable<IDependency> GetResourcesFromXmlNode(XmlNode ciXmlNode, DependencyTypeEnum.DependencyType dependencyType)
{
var allResources = GetAllResources();
foreach (var nodeItem in ciXmlNode.SelectNodes(Res.WebServiceXmlRootNode).Cast<XmlNode>())
{
Guid resourceGuid;
var isValidGuid = Guid.TryParse(nodeItem.SelectSingleNode("ResourceGuid").InnerText, out resourceGuid);
var copyOfResource = allResources.Where(m => m.Id == resourceGuid).SingleOrDefault();
if (isValidGuid && copyOfResource != null)
{
yield return new Dependency
{
Resource = copyOfResource,
Type = dependencyType
};
}
}
}
which is where the concrete type is returned.
So it looks like the problem was to do with the dependencies collection infinately depending on itself.
It seems from my debugging that iterating the IEnumerable causes a timeout and so the foreach simply skips execution of its contents where as ToList() returns as much as it can before timing out.
I may not be correct about that but it's what seems to be the case as far as I can tell.
To give a bit of background as to how this all came about I'll explain the code changes I made yesterday.
The first thing the application does is build up a collection of all resources which are filtered by resource type. These are being brought in from our CMDB via a web service call.
What I was then doing is for each resource that was selected (via autocomplete in this case) I'd make a web service call and get the dependents for the resource based on its Guid. (recursively)
I changed this yesterday so that we didn't need to obtain the full resource information in this second web service call, rather, simply obtain a list of Guids in the web service call and grab the resources from our resources collection.
What I forgot was that the web service call for dependents wasn't filtered by type and so it was returning results that didn't exist in the original resources collection.
I need to look a bit further but it seems that at this point, the new collection of dependent resources was becoming dependent on itself and thus, causing the IEnumerable<IDependents> collection later on to timeout.
This is where I've got to today, if I find anything else I'll be sure to note it here.
To summarise this:
If infinite recursion occurs in an IEnumerable it'll simply timeout
when attempting to enumerate in a foreach.
Using ToList() on the IEnumerable seems to return as much data as it
can before timing out.
I am building in a Change History / Audit Log to my MVC app which is using the Entity Framework.
So specifically in the edit method public ActionResult Edit(ViewModel vm), we find the object we are trying to update, and then use TryUpdateModel(object) to transpose the values from the form on to the object that we are trying to update.
I want to log a change when any field of that object changes. So basically what I need is a copy of the object before it is edited and then compare it after the TryUpdateModel(object) has done its work. i.e.
[HttpPost]
public ActionResult Edit(ViewModel vm)
{
//Need to take the copy here
var object = EntityFramework.Object.Single(x=>x.ID = vm.ID);
if (ModelState.IsValid)
{
//Form the un edited view model
var uneditedVM = BuildViewModel(vm.ID); //this line seems to confuse the EntityFramework (BuildViewModel() is used to build the model when originally displaying the form)
//Compare with old view model
WriteChanges(uneditedVM, vm);
...
TryUpdateModel(object);
}
...
}
But the problem is when the code retrieves the "unedited vm", this is causing some unexpected changes in the EntityFramework - so that TryUpdateModel(object); throws an UpdateException.
So the question is - in this situation - how do I create a copy of the object outside of EntityFramework to compare for change/audit history, so that it does not affect or change the
EntityFramework at all
edit: Do not want to use triggers. Need to log the username who did it.
edit1: Using EFv4, not too sure how to go about overriding SaveChanges() but it may be an option
This route seems to be going nowhere, for such a simple requirement! I finally got it to override properly, but now I get an exception with that code:
public partial class Entities
{
public override int SaveChanges(SaveOptions options)
{
DetectChanges();
var modifiedEntities = ObjectStateManager.GetObjectStateEntries(EntityState.Modified);
foreach (var entry in modifiedEntities)
{
var modifiedProps = ObjectStateManager.GetObjectStateEntry(entry).GetModifiedProperties(); //This line throws exception The ObjectStateManager does not contain an ObjectStateEntry with a reference to an object of type 'System.Data.Objects.EntityEntry'.
var currentValues = ObjectStateManager.GetObjectStateEntry(entry).CurrentValues;
foreach (var propName in modifiedProps)
{
var newValue = currentValues[propName];
//log changes
}
}
//return base.SaveChanges();
return base.SaveChanges(options);
}
}
IF you are using EF 4 you can subscribe to the SavingChanges event.
Since Entities is a partial class you can add additional functionality in a separate file. So create a new file named Entities and there implement the partial method OnContextCreated to hook up the event
public partial class Entities
{
partial void OnContextCreated()
{
SavingChanges += OnSavingChanges;
}
void OnSavingChanges(object sender, EventArgs e)
{
var modifiedEntities = ObjectStateManager.GetObjectStateEntries(EntityState.Modified);
foreach (var entry in modifiedEntities)
{
var modifiedProps = ObjectStateManager.GetObjectStateEntry(entry.EntityKey).GetModifiedProperties();
var currentValues = ObjectStateManager.GetObjectStateEntry(entry.EntityKey).CurrentValues;
foreach (var propName in modifiedProps)
{
var newValue = currentValues[propName];
//log changes
}
}
}
}
If you are using EF 4.1 you can go through this article to extract changes
See FrameLog, an Entity Framework logging library that I wrote for this purpose. It is open-source, including for commercial use.
I know that you would rather just see a code snippet showing how to do this, but to properly handle all the cases for logging, including relationship changes and many-to-many changes, the code gets quite large. Hopefully the library will be a good fit for your needs, but if not you can freely adapt the code.
FrameLog can log changes to all scalar and navigation properties, and also allows you to specify a subset that you are interested in logging.
There is an article with high rating here at the codeproject: Implementing Audit Trail using Entity Framework . It seems to do what you want. I have started to use this solution in a project. I first wrote triggers in T-SQL in the database but it was too hard to maintain them with changes in the object model happening all the time.
I'm hoping that I'm just using the API incorrectly, but for some reason, when I query my oData service from wp7, I am only receiving the last entry in the sequence. I'm pretty sure the service is working just fine as I'm able to just visit the oData query URL in the browser and get the correct results. However, the following method only ends up displaying one item on the list.
I based the following code from the sample at this blog post: http://chriskoenig.net/2010/10/30/odata-v2-and-windows-phone-7/
The observable collection which is passed in is the one which is bound to the wpf listbox.
private static void LoadRuntimeData(ObservableCollection<CategoryItem> items)
{
var catalog = GetCatalog();
var queryUri = new Uri("/Categories?&$orderby=Name", UriKind.Relative);
var categories = new DataServiceCollection<Category>(catalog);
var queryHandle = App.ViewModel.StartQuerying();
categories.LoadAsync(queryUri);
categories.LoadCompleted += (e, c) =>
{
using (queryHandle)
{
var serverItems = categories.Select(k => new CategoryItem
{
Name = k.Name,
Description = k.Description
});
items.Clear();
foreach (var item in serverItems)
{
items.Add(item);
}
}
};
}
Any tips would be greatly appreciated.
Edit: per a comment below, I've uploaded the source code in which this issue is reproducible: http://khanviewer.codeplex.com/
Taking a quick stab at this (and I suspect that Chris would know better).
But don't you need to somehow identify/tag with an attribute a primary key column (the property or properties that define uniqueness).
I know I have run into something similar to this with RIA Services, and the issue there was that I wasn't setting a value for the unique identifier column. As a result I saw all my data come down, but the when the client got the data it saw all the data as a single record.
Jay