Hey i am trying to create a class instance, which is immutable object.
So i was thinking to use proxies.
I want each time a developer will try to change the object properties,
a new object will be deep cloned from the current object.
and the result will be this new object with the changes.
its important the class proto will stay available.
Example:
class Men{
constructor(name){
this.schema = {prop: {innerProp:{}}};
this.name = name;
}
set newName(name){
this.name = name;
}
}
var handler = {
set (target, key, value) {
target = new Proxy(_.cloneDeep(target), this);
target[key] = value;
return target // Return the new obj with the change
}
};
let jeson = new Men("jeson");
let jesonProxy = new Proxy(jeson, handler);
// Taking the new jeson proxy with the change
let newJesonProxy = (jesonProxy.schema = {newProp: {newInnerProp: {}}});
Thanks in advance.
No, you cannot use a proxy for this, and setters not either. They do not allow you to change the result of the assignment. Use an ordinary method for creating the changed instances, and simply freeze the objects.
class Man {
constructor(name) {
this.schema = {prop: {innerProp:{}}};
this.name = name;
Object.freeze(this);
}
withName(name) {
return new this.constructor(name);
}
}
const x = new Man("");
const y = x.withName("jeson");
Related
When the Icon clicked, viewModel.onLockIconClicked(it) is called to reverse the value of isLock in db.
The Icon is expected to be updated according based on the value of isLock.
I've checked the value did reversed in db table. But LazyColumn not update accordingly.
What did I miss? Thanks a lot!
Ex, initially, Screen: icon = lock and Db: isLock = true,
when Icon clicked, Screen: icon = lock and Db: isLock = false,
while expected is Screen: icon = lock_open and Db: isLock = false.
ListScreen:
#Composable
fun ListScreen(context: Context) {
val viewModel: ListViewModel =
viewModel(factory = ListViewModelFactory(Db.getInstance(context)))
val list by viewModel.list.collectAsState(initial = emptyList())
Scaffold() {
SwipeRefresh(
state = rememberSwipeRefreshState(viewModel.isRefreshing),
onRefresh = { }
) {
LazyColumn(
state = rememberLazyListState(),
) {
items(list) {
Row() {
Icon(
painter = painterResource(if (it.isLock) R.drawable.ic_baseline_lock_24 else R.drawable.ic_baseline_lock_open_24),
contentDescription = null,
modifier = Modifier.clickable() { viewModel.onLockIconClicked(it) }
)
Text(it.code)
}
}
}
}
}
}
ListViewModel:
class ListViewModel(db: Db) : ViewModel() {
private val sumDao = db.sumDao()
val list = sumDao.getAllRows()
var isRefreshing by mutableStateOf(false)
private set
//init
init {
viewModelScope.launch(Dispatchers.IO) {
val initialCodeList = listOf("aaa", "bbb")
for (code in initialCodeList) {
val sum = Sum()
sum.code = code
sumDao.insert(sum)
}
}
}
fun onLockIconClicked(sum: Sum) {
sum.isLock = !sum.isLock
viewModelScope.launch(Dispatchers.IO) {
sumDao.update(sum)
}
}
}
class ListViewModelFactory(private val db: Db) : ViewModelProvider.Factory {
override fun <T : ViewModel> create(modelClass: Class<T>): T {
if (modelClass.isAssignableFrom(ListViewModel::class.java)) {
#Suppress("UNCHECKED_CAST")
return ListViewModel(db) as T
}
throw IllegalArgumentException("Unknown ViewModel class")
}
}
Sum:
#Entity(tableName = "sum", primaryKeys = ["code"])
data class Sum(
#ColumnInfo(name = "code")
var code: String = "",
#ColumnInfo(name = "is_lock")
var isLock: Boolean = true
)
SumDao:
#Dao
interface SumDao {
#Insert(onConflict = OnConflictStrategy.REPLACE)
suspend fun insert(sum: Sum): Long
#Update(onConflict = OnConflictStrategy.REPLACE)
suspend fun update(sum: Sum): Int
#Delete
suspend fun delete(sum: Sum): Int
#Query("select * from sum")
fun getAllRows(): Flow<List<Sum>>
}
Db:
#Database(entities = [Sum::class], version = 1, exportSchema = false)
abstract class Db : RoomDatabase() {
abstract fun sumDao(): SumDao
companion object {
#Volatile
private var INSTANCE: Db? = null
fun getInstance(context: Context): Db {
return INSTANCE ?: synchronized(this) {
val instance = Room.databaseBuilder(
context.applicationContext,
Db::class.java,
"db"
)
.fallbackToDestructiveMigration()
.build()
INSTANCE = instance
return instance
}
}
}
}
Consider taking the State-in-Compose for a better understanding of the concepts of state-handling in Compose.
I'm sorry but the information that you have provided is massive, so I can't pinpoint the source of the bug, but here's what you can do for now:
In your Dao class, just replace the words Flow<List<Sum>> with LiveData<List<Sum>>
In your ViewModel, you can get access to the LiveData inside the init like so
var list by mutableStateListOf<Sum>()
init{
sumDao.getAllRows().observeForever{
list = it
}
}
Now, list would ideally be updated every time the value in the databse changes, which infact would trigger recompositions since I am using a direct mutableStateListOf object here.
The problem may lie anywhere:
Since the class Sum is a custom-made class, it may have been experiencing issues triggering recompositions, which is a common problem among new developers, and even some experienced ones nowadays.
Since you are declaring the viewModel inside the Composable, wrong instances of ViewModels may have been passed around, leading to state-inconsistency - always try to declare your viewModels in the top-most layer possibly, i.e., somewhere like the onCreate method of the activity. Fragments are discourages so you should not face any problems over there.
Since you were not actively observing the Flow anywhere, that could have lead to the variable not being updated at all in the ViewModel, which would again lead to UI-inconsistency.
I would like to consume my organizations dynamics oData endpoint but with early bound classes. However, there are a lot of early bound tools out there and I wanted to know which one provides the best developer experience/least resistance?
For example, there is this one:
https://github.com/daryllabar/DLaB.Xrm.XrmToolBoxTools
https://github.com/yagasoft/DynamicsCrm-CodeGenerator
and so on. Is there a developer preference/method out there?
Early bound classes are for use with the Organization Service which is a SOAP service. The normal way to generate those classes is using CrmSvcUtil.
OData can be used in Organization Data Service or Web API, but those don't have Early Bound classes.
Further reading: Introducing the Microsoft Dynamics 365 web services
It's not impossible to use with standard SOAP Early bound class. We just have to be creative. If we work just with basic attributes (fields, not relationships, ecc) it seems possible. For example. for create and update, OData will not accept the entire early bounded class, just pass the attibutes:
class Program
{
static void Main(string[] args)
{
string token = System.Threading.Tasks.Task.Run(() => GetToken()).Result;
CRMWebAPI dynamicsWebAPI = new CRMWebAPI("https:/ORG.api.crm4.dynamics.com/api/data/v9.1/",
token);
CRMGetListOptions listOptions = new CRMGetListOptions
{
Select = new string[] { "EntitySetName" },
Filter = "LogicalName eq 'contact'"
};
dynamic entityDefinitions = dynamicsWebAPI.GetList<ExpandoObject>("EntityDefinitions", listOptions).Result;
Contact contact = new Contact
{
FirstName = "Felipe",
LastName = "Test",
MobilePhone = "38421254"
};
dynamic ret = System.Threading.Tasks.Task.Run(async () => await dynamicsWebAPI.Create(entityDefinitions.List[0].EntitySetName, KeyPairValueToObject(contact.Attributes))).Result;
}
public static async Task<string> GetToken()
{
string api = "https://ORG.api.crm4.dynamics.com/";
ClientCredential credential = new ClientCredential("CLIENT_ID", "CLIENT_SECRET");
AuthenticationContext authenticationContext = new AuthenticationContext("https://login.microsoftonline.com/commom/oauth2/authorize");
return authenticationContext.AcquireTokenAsync(api, credential).Result.AccessToken;
}
public static object KeyPairValueToObject(AttributeCollection keyValuePairs)
{
dynamic expando = new ExpandoObject();
var obj = expando as IDictionary<string, object>;
foreach (var keyValuePair in keyValuePairs)
obj.Add(keyValuePair.Key, keyValuePair.Value);
return obj;
}
}
It's a simple approach and I didn't went further.
Maybe we have to serealize other objects as OptionSets, DateTime (pass just the string) and EntityReferences but this simple test worked fine to me. I'm using Xrm.Tools.WebAPI and Microsoft.IdentityModel.Clients.ActiveDirectory. Maybe it's a way.
[Edit]
And so I decided to go and created a not well tested method to cast the attributes. Problems: We have to follow OData statments to use the API. To update/create an entity reference we can use this to reference https://www.inogic.com/blog/2016/02/set-values-of-all-data-types-using-web-api-in-dynamics-crm/
So
//To EntityReference
entityToUpdateOrCreate["FIELD_SCHEMA_NAME#odata.bind"] = "/ENTITY_SET_NAME(GUID)";
So, it's the Schema name, not field name. If you use CamelCase when set you fields name you'll have a problem where. We can resolve that with a (to that cute) code
public static object EntityToObject<T>(T entity) where T : Entity
{
dynamic expando = new ExpandoObject();
var obj = expando as IDictionary<string, object>;
foreach (var keyValuePair in entity.Attributes)
{
obj.Add(GetFieldName(entity, keyValuePair), CastEntityAttibutesValueOnDynamicObject(keyValuePair.Value));
}
return obj;
}
public static object CastEntityAttibutesValueOnDynamicObject(object attributeValue)
{
if (attributeValue.GetType().Name == "EntityReference")
{
CRMGetListOptions listOptions = new CRMGetListOptions
{
Select = new string[] { "EntitySetName" },
Filter = $"LogicalName eq '{((EntityReference)attributeValue).LogicalName}'"
};
dynamic entitySetName = dynamicsWebAPI.GetList<ExpandoObject>("EntityDefinitions", listOptions).Result.List[0];
return $"/{entitySetName.EntitySetName}({((EntityReference)attributeValue).Id})";
}
else if (attributeValue.GetType().Name == "OptionSetValue")
{
return ((OptionSetValue)attributeValue).Value;
}
else if (attributeValue.GetType().Name == "DateTime")
{
return ((DateTime)attributeValue).ToString("yyyy-MM-dd");
}
else if (attributeValue.GetType().Name == "Money")
{
return ((Money)attributeValue).Value;
}
else if (attributeValue.GetType().Name == "AliasedValue")
{
return CastEntityAttibutesValueOnDynamicObject(((AliasedValue)attributeValue).Value);
}
else
{
return attributeValue;
}
}
public static string GetFieldName<T>(T entity, KeyValuePair<string, object> keyValuePair) where T : Entity
{
switch (keyValuePair.Value.GetType().Name)
{
case "EntityReference":
var entityNameList = System.Threading.Tasks.Task.Run(async () => await dynamicsWebAPI.GetEntityDisplayNameList()).Result;
var firstEntity = entityNameList.Where(x => x.LogicalName == entity.LogicalName).FirstOrDefault();
var attrNameList = System.Threading.Tasks.Task.Run(async () => await dynamicsWebAPI.GetAttributeDisplayNameList(firstEntity.MetadataId)).Result;
return attrNameList.Where(x => x.LogicalName == keyValuePair.Key).Single().SchemaName + "#odata.bind";
case "ActivityParty":
throw new NotImplementedException(); //TODO
default:
return keyValuePair.Key;
}
}
Please, note that this approach do not seems fast or good in anyway. It's better if you have all this values as static so we can save some fetches
[Edit 2]
I just found on XRMToolBox a plugin called "Early bound generator for Web API" and it seems to be the best option. Maybe you should give it a try if you're still curious about that. I guess its the best approach.
The final code is this:
static void Main(string[] args)
{
string token = Task.Run(() => GetToken()).Result;
dynamicsWebAPI = new CRMWebAPI("https://ORG.api.crm4.dynamics.com/api/data/v9.1/",
token);
Contact contact = new Contact
{
FirstName = "Felipe",
LastName = "Test",
MobilePhone = "38421254",
new_Salutation = new EntityReference(new_salutation.EntitySetName, new Guid("{BFA27540-7BB9-E611-80EE-FC15B4281C8C}")),
BirthDate = new DateTime(1993, 04, 14),
};
dynamic ret = Task.Run(async () => await dynamicsWebAPI.Create(Contact.EntitySetName, contact.ToExpandoObject())).Result;
Contact createdContact = dynamicsWebAPI.Get<Contact>(Contact.EntitySetName, ret, new CRMGetListOptions
{
Select = new string[] { "*" }
}).Result;
}
and you have to change the ToExpandoObject on Entity.cs class (generated by the plugin)
public ExpandoObject ToExpandoObject()
{
dynamic expando = new ExpandoObject();
var expandoObject = expando as IDictionary<string, object>;
foreach (var attributes in Attributes)
{
if (attributes.Key == GetIdAttribute())
{
continue;
}
var value = attributes.Value;
var key = attributes.Key;
if (value is EntityReference entityReference)
{
value = $"/{entityReference.EntitySetName}({entityReference.EntityId})";
}
else
{
key = key.ToLower();
if (value is DateTime dateTimeValue)
{
var propertyForAttribute = GetPublicInstanceProperties().FirstOrDefault(x =>
x.Name.Equals(key, StringComparison.InvariantCultureIgnoreCase));
if (propertyForAttribute != null)
{
var onlyDateAttr = propertyForAttribute.GetCustomAttribute<OnlyDateAttribute>();
if (onlyDateAttr != null)
{
value = dateTimeValue.ToString(OnlyDateAttribute.Format);
}
}
}
}
expandoObject.Add(key, value);
}
return (ExpandoObject)expandoObject;
}
Links:
https://github.com/davidyack/Xrm.Tools.CRMWebAPI
https://www.xrmtoolbox.com/plugins/crm.webApi.earlyBoundGenerator/
We currently use XrmToolkit which has it's own version of early binding called ProxyClasses but will allow you to generate early binding using the CRM Service Utility (CrmSvcUtil). It does a lot more than just early binding which is why we use it on all of our projects but the early binding features alone would have me sold on it. in order to regenerate an entity definition all you do is right click the cs file in visual studio and select regenerate and it is done in a few seconds.
For my first 3 years of CRM development I used the XrmToolbox "Early Bound Generator" plugin which is really helpful as well.
There are a lot of methods to convert a string/List to a list of something else.
Out of curiosity I can't find if there is a way to do it this way
Directory.EnumerateFiles(#"C:\Drivers").ToList<FileInfo>();
Or Either
new List<string>(Directory.EnumerateFiles(#"C:\Drivers")).Cast<FileInfo>();`
`
As fileinfo takes FileInfo(path) as parameter, there is a way to do like this or a short oneliner which doesn't involve linq Select(x => new FileInfo(x) or something like that?
There is nothing built-in that does this (binding to a constructor). I am not sure why you would want to avoid Select(x => new FileInfo(x)). However, you could if you wanted to define an extension method such as the below Construct to perform the binding:
static void Main(string[] args)
{
const string path = "d:\\";
var results = Directory.EnumerateFiles(path).Construct<string, FileInfo>();
}
private static ConcurrentDictionary<Type, object> constructors = new ConcurrentDictionary<Type, object>();
private static IEnumerable<TOutput> Construct<TInput, TOutput>(this IEnumerable<TInput> input)
{
var constructor = constructors.GetOrAdd(typeof(TOutput), (Type type) =>
{
var parameterExpression = Expression.Parameter(typeof(TInput));
var matchingConstructor = typeof(TOutput).GetConstructor(new[] { typeof(TInput) });
var expression = Expression.Lambda<Func<TInput, TOutput>>(Expression.New(matchingConstructor, parameterExpression), parameterExpression);
return (object)expression.Compile();
});
return input.Select(x => ((Func<TInput,TOutput>)constructor)(x));
}
How may I avoid to duplicate the code I use for mapping a database entity to a poco object?
Given this code:
private IQueryable<DummyExtended> Find()
{
return (from dt in Entities.dummy_table
select new DummyExtended
{
Description = dt.table_1.table_2.description,
Dummy = new Dummy
{
Name = d.name,
Notes = d.notes,
HelpText = d.help_text
}
}).AsQueryable();
}
Can I create a common linq expression to be re-used for both methods?
private IQueryable<DummyExtended> Find()
{
return (from dt in Entities.dummy_table
select new DummyExtended
{
Description = dt.table_1.table_2.description,
Dummy = ...???
}).AsQueryable();
}
private IQueryable<DummyAlsoExtended> FindAnother()
{
return (from dt in Entities.dummy_table
select new DummyAlsoExtended
{
InnerHtml = dt.table_html.description,
Dummy = ....??
}).AsQueryable();
}
Example:
public static Expression<Func<dummy_table, Dummy>> EntityToPoco()
{
return d => new Dummy
{
Name = d.name,
Notes = d.notes,
HelpText = d.help_text
};
}
I can't quite get it right
....
Dummy = ExtensionClass.EntityToPoco()
So you have a dummy_table which is a Enumerable or Queryable sequence of objects. Let's assume that the sequence contains objects of class DummyTableElement.
You showed, that if you have a DummyTableElement you know how to convert it into a Dummy object. You want to reuse this function to create other objects like DummyExtended and DummyAlsoExtended. If you want to do this LINQ-alike, it is best to create extension functions for it:
static class DummyTableElementExtensions
{
public static Dummy ToDummy(this TableElement tableElement)
{
return new Dummy()
{
Name = tableElement.name,
Notes = tableElement.notes,
HelpText = tableElement.help_text
};
}
}
Once you have this, you can create similar functions to convert TableElements into DummyExtended and DummyAlsoExtended. They will be one-liners.
In the same extension class:
public static DummyExtended ToDummyExtended(this TableElement tableElement)
{
return new DummyExtended()
{
Description = tableElement.table_1.table_2.description,
Dummy = tableElement.ToDummy(),
};
}
public static DummyAlsoExtended ToDummyAlsoExtended(this TableElement tableElement)
{
return new DummyAlsoExtended
{
InnerHtml = tableElement.table_html.description,
Dummy = tableElement.ToDummy(),
};
}
And once you've got these, you can create extension functions to convert any IQueryable of TableElements:
public static IQueryable<DummyExtended> ToDummyExtended(
this IQueryable<TableElement> tableElements)
{
return tableElements
.Select(tableElement => tableelement.ToDummyExtended();
}
And a similar one-line function for DummyAlsoExtended.
Your Find function and FindAnother function will also be one-liners:
private IQueryable<DummyExtended> Find()
{
return dummy_table.ToDummyExtended();
}
private IQueryable<DummyAlsoExtended> FindAnother()
{
return dummy_table.ToDummyAlsoExtended();
}
I'm not sure why you wanted to use an expression in this. It doesn't seem that DummyExtended and DummyAlsoExtended are really similar, except that they both have a property Dummy.
One reason to parameterize the destination of your find function could be because you want to create anonymous classes in your Find function.
Again, once you've created ToDummy this will be a one-liner:
public static IQueryable<TResult> Find<TSource, TResult>(
this IQueryable<TSource> source,
Expression<Func<TSource, TResult>> resultSelector)
{
return source.Select(sourceElement => resultSelector(sourceElement);
}
Usage would be:
var X = dummy_Table.find(tableElement => new
{
foo = tableElement.CalculateFoo(),
bar = tableElement.CalculateBar(),
Dummy = tableElement.ToDummy(),
});
Is there any "automatic way" to casts an "Object" to a personalized Model Data Type in ActionScript 3?
Example:
package Example{
public class ExampleModel{
private _id:int;
private _randomAttribute:String;
public function ExampleModel(){
_id = 0;
_randomAttribute = "";
}
public function get id():int{
return _id;
}
public function set id(value:int):void{
_id = value;
}
public function get randomAttribute():String{
return _randomAttribute;
}
public function set randomAttribute(value:String):void{
_randomAttribute = value;
}
}
}
Then, in some part of my code, lets assume that I have something like this:
var _obj:Object = new Object();
_obj.id = 1;
obj.randomAttribute = "Hello World";
What I want would be something like:
var _exampleModel:ExampleModel = obj as ExampleModel;
But when I do this, the result on _exampleModel is null.
Any ideas?
Thanks.
EDIT:
According to Manish's answer, all I changed was the type of p var, which allows me to go through every kind of attribute:
public function fromObject(obj:Object):void{
//p:* includes every type of attributes.
for (var p:* in obj)
if (this.hasOwnProperty(p))
// Set private var directly.
this["_" + p] = obj[p];
}
Thanks Manish and rcdmk.
Manish's answer was enough for me and according to rcdmk's comment, the p:String isn't about the Type of data that the loop will go through, it is actually the name of the property, which makes sense because every name is a String.
The only way to automatically "cast" it is the following:
var model:Model = new Model();
var obj:Object = { id: "98123", name: "John Doe" };
for (var p:String in obj) {
if (model.hasOwnProperty(p))
model[p] = obj[p];
}
(Note: Model.id and Model.name are both type String in my example.)
A more proper way to do it, of course, is to pass the plain object to the Model object and let the Model object absorb it.
var model:Model = new Model(obj);
Or:
var model:Model = new Model();
model.fromObject(obj);
Where in the Model code you have:
public function Model(obj:Object = null)
{
if (obj != null)
fromObject(obj);
}
public function fromObject(obj:Object):void
{
for (var p:String in obj)
if (this.hasOwnProperty(p))
// Set private var directly.
this["_" + p] = obj[p];
}
This code can be in your abstract base Model class, and all your specific Model subclasses (e.g. ProductModel, CustomerModel, etc.) can use it automatically.
e.g.
public class ProductModel extends Model
{
public function ProductModel(obj:Object = null)
{
super(obj);
}
}