I am trying to understand how to use Action and parameters in DialogFlow. Is it required to have Action name in DialogFlow? Can we use just parameters and leave Action field blank?
Yes, you can leave the action field empty but that would result in a bad design for your application.
Let me give you an example on How would use it to map Dialogflow Intents to my class and methods.
Suppose, you have following intents:
Get.Transactions: This intent is suppose to fetch all transactions from the backed app. Let's say it has action name as all.transactions.
Get.Transactions.Followup.Breakdown: This intent is a follow-up intent of the first one and it is supposed to breakdown all the transactions based on certain criteria. Let's say it has an action name as breakdown.transactions.
Now, these two intents are related and works on the similar dataset to produce different result.
In the first intent, my application fetches all the transactions from the database and presents it to the user. And in the second intent, the same list of transactions are broken down into different sets based on some criteria provided by the user. It would be wise to keep both the functionality enclosed in the same class.
So, I would map both the intents to the same class but invoke different methods based on the actions parameter value. That way my code would look something like:
public class Transaction {
public WebhookResponse performAction(WebhookRequest webhookRequest) {
String actionName = webhookRequest.getAction();
switch (actionName) {
case "all.transactions":
List<Transaction> transactions = fetchAllTransactions(webhook.getParams("userId"));
// make response
break;
case "breakdown.transactions":
List<Transaction> transactions = breakdownTransaction(webhook.getParams("userId"), webhook.getParams("breakdownCriteria")));
// make response
break;
default:
// default response
break;
}
return response;
}
private List<Transaction> fetchAllTransactions(int userId) {
// connect to the database
// fetch all transactions
// return the result in a form of list
}
private List<Transaction> breakdownTransaction(int userId, String breakdownCriteria) {
List<Transaction> transactions = fetchAllTransactions(userId);
// loop transactions
// breakdown transactions based on some criteria
// return list of transactions
}
}
This is how you can map two different intents to the same class at your backend.
I have pushed a similar design architecture into git. You can refer the code in the following link: https://github.com/vslala/ChatbotDemo/tree/external_intent_mapping
(Let me know if you have any doubts)
Note: The example has been given using JAVA language.
Yes, you can leave it empty if you want. It is only used to identify the action you are doing in each intent.
There is a simple example in the documentation.
Related
I am using Spring Data JPA and QueryDsl (v.4.2.2), Java 8. I can explicitly construct search predicates and pass them to the repository methods. However, I like the idea of using the #QuerydslPredicate annotation on a web/REST controller's method argument when the queried entities have more than a few properties, and I want the flexibility of filtering the search by any of them. So, something like this, generally, works very well:
#GetMapping("/accounts/summaries")
public PageDto<AccountSummaryDto> getAccountSummaries(#QuerydslPredicate(root = AccountSummary.class) Predicate accountSearchPredicate,
#RequestParam(name = "pageIndex", defaultValue = "0") int pageIndex,
#RequestParam(name = "pageSize", defaultValue = "25") int pageSize,
#RequestParam(name = "sortBy", defaultValue = "id") String sortBy,
#RequestParam(name = "sortOrder", defaultValue = "desc") String sortOrder) {
// delegating to web-agnostic service that:
// - creates Pageable pageRequest,
// - calls accountSummaryRepository.findAll(predicate, pageRequest),
// - constructs custom PageDto wrapper, etc.
return accountService.retrieveAccountSummaries(accountSearchPredicate, pageIndex, pageSize, sortBy, sortOrder);
}
My Spring Data JPA repository interface looks similar to this:
public interface AccountSummarySearchRepository
extends JpaRepository<AccountSummary, Integer>, QuerydslPredicateExecutor<AccountSummary>, QuerydslBinderCustomizer<QAccountSummary > {
#Override
default void customize(QuerydslBindings bindings, QAccountSummary acctSummary) {
bindings.bind(acctSummary.customer.firstName).first((path, value) -> path.isNull().or(path.startsWithIgnoreCase(value))) ;
bindings.bind(acctSummary.customer.lastName).first((path, value) -> path.isNull().or(path.startsWithIgnoreCase(value))) ;
// etc.
// default binding for String properties to be case insensitive "contains" match
bindings.bind(String.class).first(
(StringPath path, String value) -> path.isNull().or(path.containsIgnoreCase(value)));
}
My question:
The bindings in the customize method are set using the entity field
paths and the values of the request parameters that match those
paths. If the parameter is not specified, is there a way to bind the
path to some constant value or a value obtained dynamically?
For example, I want to always ONLY retrieve the entities where property deleted is set to false - without forcing the client to pass that as a query parameter? Similarly, I may want to set other default lookup values dynamically for each query. For example, I may want to "retrieve only those accounts where assignedTo == [current user ID available on a ThreadLocal]...
The following will not work
bindings.bind(acctSummary.deleted).first((path, value) -> path.eq(false));
because it, obviously, expects the first occurrence of the path/value pair for deleted=... in the Predicate (mapped from the incoming request params via the #QuerydslPredicate annotation. I don't want to pass that as a parameter because the requester does not even need to know about the existence of such field.
Is there a simple way to infuse the Predicate instance that is auto-populated via the #QuerydslPredicate annotation with any additional implicit/default criteria that are not explicitly passed in the web request? Could this be done in the customize method? I suppose, one (very ugly) way would be to intercept the HTTP request in a filter - before it is processed by the Spring-QueryDsl framework - and replace it with a new request with added parameters? That would be a horrible solution, and I feel there has to be a better way to do it via some hook/capability provided by the framework itself.
Unfortunately, there seem to be no comprehensive documentation for Spring QueryDsl support - other than some very simplistic examples.
Thanks for your help!
Answering my own question... I was hoping to find a hook in the framework where I could add the code to enhance the auto-generated predicate with criteria common for all my queries - before it arrives in the controller method, but wasn’t able to figure that out. Overriding QuerydslPredicateArgumentResolver doesn't seem a good or necessary option. And, quite frankly, I've come to the conclusion that this wasn't such a great idea to begin with. It seems that any modifications to the search criteria should be done in a more obvious way - in the business tier. So I decided to simply update the predicate in the service method:
public PageDto<AccountSummaryDto> retrieveByPredicate(Predicate predicate, int pageIndex, int pageSize, String sortBy, String sortOrder) {
Pageable pageRequest = PageRequest.of(pageIndex, pageSize, Sort.Direction.fromString(sortOrder), sortBy);
QAccountSummary accountSummary = QAccountSummary.accountSummary; //QueryDsl auto-generated query type for AccountSummary (path root)
// construct new enhanced search predicate w/added criteria common for all queries
// using original predicate generated by framework from request params as base
BooleanBuilder updatedPredicate = new BooleanBuilder(predicate)
.and(accountSummary.somethingNested.id.eq(SomeThreadContext.getSomethingId()))
.and(accountSummary.deleted.eq(false))
.and(accountSummary.someProperty.eq("xyz"));
Page<accountSummary> page = summarySearchRepository.findAll(updatedPredicate, pageRequest);
return toAccountSummaryPageDto(page); // custom method that converts results to page DTO w/entity dots and page stats
}
The construction of the updated predicate may be extracted into a separate private method on the service should it be desirable to use it in multiple search methods and/or if more logic is required to dynamically generate additional search criteria.
I have read this post and the theory I think that is clear. I have a DAL that only has the methods to add, get, update and delete information in a database.
So I guess that I have an application in which I have clients, orders and type of client. Type of client has a percent that set the discount to make to a type of client.
The business layer request to DAL the type of client to know the discount.
The business layer create the order with the price and apply the discount according to the type of client.
The business layer send to the DAL the command to add the new order, sending the new order.
In code I can have this:
DAL:
public async getClientType(long paramIDClientType)
{
using(Entities myDbContext = new Entities())
{
return await myDbContext.ClientTypes.Where(x=> x.IDType == paramIDClientType).SingleOrDefault();
}
}
public async addOrder(Orders paramNewOrder)
{
using(Entities myDbContext = new Entities())
{
myDbContext.Orders.Local.Add(paramNewOrder);
await myDbContext.SaveChangesAsync();
}
}
Business layer:
public void addOrderToClient(CLients paramClient)
{
ClientTypes myType = myDAL.getClientType(paramClient.IDClient);
ORder myNewOrder = myNewOder();
myNewOrder.IDClient = paramClientIdCLient;
myNewOder.Amount = 300;
myNewOrder.Discount = myType.Discount;
myNewOder.Total = nyNewOrder.Total - myNewOder.Amount * myNewOder.Discount;
myDAL.AddOrder(nyNewOrder);
}
But I have a problem with the concurrency in this case, because I want to ensure that I use the correct discount, so I want to avoid the discount of a type of client is changed by another user un the middle of the process of add the new order.
If I use optimistic concurrency, I have to have a timestamp column in my ClientTypes table, but this not solve my problem, because in the addOrder method in my DAL layer, I only pass as parameter the new order, so the method don't have the timestamp value that has the business layer to check if the type of the client has changed to ensure that the discount used is the correct.
SO I am thinking in this solution:
public async addOrder(Orders paramNewOrder)
{
using(Entities myDbContext = new Entities())
{
string sql = "select ct.* from ClientTypes as ct, CLients as c"
+ " where ct.IdType = c.IdType and c.IdType = " + paramNewOrder.IdCLient;
ClientTypes myClientType = await myDbContext.CLientTypeSqlQuery<CLientTypes>(sql).SingleOrDefaultAsync();
if(paramNewOrder.Discount != myCLientType)
{
throw new Exception("Discount incorrect.");
}
paramNewOrder.Total = paramNewOrder.Amount - paramNewOrder.Amount * myClientType.Discount;
myDbContext.Orders.Local.Add(paramNewOrder);
await myDbContext.SaveChangesAsync();
}
}
This is my business layer, but use EF to get the data, so I think that this solution merge DAL abd business layer. Is this true? If this is true, I guess that is a not good solution. But then, how could I control concurrency?
Thanks.
Yes, optimistic concurrency control doesn't help you to prevent inserting a faulty new order, because you don't commit the ClientType. Only updating a ClientType would raise an exception if the discount was changed in the mean time.
But carefully consider the requirements. Is it really of paramount importance that the correct discount is used milliseconds after it's modified? If so, you have to look for a locking mechanism. Otherwise, just fetch the current discount at the very last moment, do the calculation and commit the order.
You could implement a locking/calculation/insert mechanism in a stored procedure that is mapped to the insert action of an Order. EF can map CUD actions to stored procedures..
I'm trying to create rest api for my application to get the data in my android app. This is my controller
<?php
namespace api\modules\v1\controllers;
use yii\rest\ActiveController;
use yii\filters\auth\QueryParamAuth;
/**
* Tk103 Controller API
*/
class Tk103Controller extends ActiveController
{
public $modelClass = 'api\modules\v1\models\Tk103CurrentLocation';
public function behaviors()
{
$behaviors = parent::behaviors();
$behaviors['authenticator'] = [
'class' => QueryParamAuth::className(),
];
return $behaviors;
}
}
I added access_token column in my user table, implemented findIdentityByAccessToken() in User Model and calling this URL
http://localhost:7872/api/v1/tk103s?access-token=abcd
This is working great and returning data if and only if access_token matches with any single user in the table.
I checked QueryParamAuth class and found that QueryParamAuth::authenticate() returns $identity after successful authentication.
Currently this url is returning whole data of my table.
What I want is(after authentication):
Get user id/username of the requester.
Based on that id/username, the data related to him as per relations of tables in db. (currently whole rows are being returned but I want only few that are matching with the current requester/user)
I tried but didn't getting any clue to catch returned $identity of user after authentication.
And I know it is possible too to make this work. Help me out folks to create magic.
Get user id/username of the requester.
That user instance you did return within the findIdentityByAccessToken method should be accessible any where inside your app within Yii::$app->user->identity. And should hold all the attributes retreived from DB. here is a quick example of using it to check access within the checkAccess method of the ActiveController class:
public function checkAccess($action, $model = null, $params = [])
{
// only an image owner can request the related 'delete' or 'update' actions
if ($action === 'update' or $action === 'delete') {
if ($model->user_id !== \Yii::$app->user->identity->id)
throw new \yii\web\ForbiddenHttpException('You can only '.$action.' images that you\'ve added.');
}
}
Note that the checkAccess is by default an empty method that is manually called inside all the built-in actions in ActiveController. the Idea is to pass the action ID and the model instance to it just after retrieving it from DB and before modifying it so we can do extra checks. If you just need to perform checks by actions ID then yii\filters\AccessControl may be enough but inside checkAccess you are expecting to also get the model instance itself so it is important to note that when building your own actions or overriding existing onces. be sure to manually invoke it the same way it is done in UpdateAction.php or DeleteAction.php.
whole rows are being returned but I want only few .. matching with .. current requester/user
It depends on how your data is structured. You can override ActiveController's actions to filter results before outputting them, it can be handled in the related SearchModel class if you are using one or it can be handled in model. A quick tip may be by simply overriding the find method inside your model:
public static function find()
{
return parent::find()->where(['user_id' => Yii::$app->user->getId()]); // or Yii::$app->user->identity->id
}
Note that this works only when using ActiveRecord. Which means when using this:
$images = Image::find()->all();
The find method we just overriden will be filtered by default by always including that where condition before generating the DB query. Also note the default built-in actions in ActiveController are using ActiveRecords but if you are using actions where you are constructing the SQL queries using the Query Builder then you should manually do the filtering.
The same can be done if using ActiveQuery (maybe better explained here) by doing this:
public static function find()
{
$query = new \app\models\Image(get_called_class());
return $query->andWhere(['user_id' => Yii::$app->user->getId()]);
}
I'm trying to understand RxJava and I'm sure this question is a nonsense... I have this code using RxJava:
public Observable<T> getData(int id) {
if (dataAlreadyLoaded()) {
return Observable.create(new Observable.OnSubscribe<T>(){
T data = getDataFromMemory(id);
subscriber.onNext(data);
});
}
return Observable.create(new Observable.OnSubscribe<T>(){
#Override
public void call(Subscriber<? super String> subscriber) {
T data = getDataFromRemoteService(id);
subscriber.onNext(data);
}
});
}
And, for instance, I could use it this way:
Action1<String> action = new Action<String>() {
#Override
public void call(String s) {
//Do something with s
}
};
getData(3).subscribe(action);
and this another with callback that implements Runnable:
public void getData(int id, MyClassRunnable callback) {
if (dataAlreadyLoaded()) {
T data = getDataFromMemory(id);
callback.setData(data);
callback.run();
} else {
T data = getDataFromRemoteService(id);
callback.setData(data);
callback.run();
}
}
And I would use it this way:
getData(3, new MyClassRunnable()); //Do something in run method
Which are the differences? Why is the first one better?
The question is not about the framework itself but the paradigm. I'm trying to understand the use cases of reactive.
I appreciate any help. Thanks.
First of all, your RxJava version is much more complex than it needs to be. Here's a much simpler version:
public Observable<T> getData(int id) {
return Observable.fromCallable(() ->
dataAlreadyLoaded() ? getDataFromMemory(id) : getDataFromRemoteService(id)
);
}
Regardless, the problem you present is so trivial that there is no discernible difference between the two solutions. It's like asking which one is better for assigning integer values - var = var + 1 or var++. In this particular case they are identical, but when using assignment there are many more possibilities (adding values other than one, subtracting, multiplying, dividing, taking into account other variables, etc).
So what is it you can do with reactive? I like the summary on reactivex's website:
Easily create event streams or data streams. For a single piece of data this isn't so important, but when you have a stream of data the paradigm makes a lot more sense.
Compose and transform streams with query-like operators. In your above example there are no operators and a single stream. Operators let you transform data in handy ways, and combining multiple callbacks is much harder than combining multiple Observables.
Subscribe to any observable stream to perform side effects. You're only listening to a single event. Reactive is well-suited for listening to multiple events. It's also great for things like error handling - you can create a long sequence of events, but any errors are forwarded to the eventual subscriber.
Let's look at a more concrete with an example that has more intrigue: validating an email and password. You've got two text fields and a button. You want the button to become enabled once there is a email (let's say .*#.*) and password (of at least 8 characters) entered.
I've got two Observables that represent whatever the user has currently entered into the text fields:
Observable<String> email = /* you figure this out */;
Observable<String> password = /* and this, too */;
For validating each input, I can map the input String to true or false.
Observable<Boolean> validEmail = email.map(str -> str.matches(".*#.*"));
Observable<Boolean> validPw = password.map(str -> str.length() >= 8);
Then I can combine them to determine if I should enable the button or not:
Observable.combineLatest(validEmail, validPw, (b1, b2) -> b1 && b2)
.subscribe(enableButton -> /* enable button based on bool */);
Now, every time the user types something new into either text field, the button's state gets updated. I've setup the logic so that the button just reacts to the state of the text fields.
This simple example doesn't show it all, but it shows how things get a lot more interesting after you get past a simple subscription. Obviously, you can do this without the reactive paradigm, but it's simpler with reactive operators.
When exposing querystring parameters using GET I have the following base URL:
https://school.service.com/api/students
This will return the first 25 students.
What if I want to return a list of students based on ONE of the following criteria:
* have accepted a job
* have received a job offer
* have no job offers
The three above choices are essentially an enum.
Therefore, the query request for students who have no job offers I assume would look like:
https://school.service.com/api/students?jobOfferStatus=3
However, I'm wondering if jobOfferStatus=3 is the proper way to handle this. If so, how would I publish/provide to the clients a list of available options for that jobOfferStatus query parameter? What about other possible query parameters and their valid options? We'll have many possible query parameters like this.
I'd love to see an example of how this should be done properly. What are the best practices?
There are two main options: documenting it, or making it discoverable. A lot of APIs have documentation where they list all of the resources and parameters for reference. Otherwise, the client won't know.
You could also make it discoverable in some way by including the options in a response. For conventions on this, search for HATEOAS if you haven't already. (I'm not really knowledgeable enough about HATEOAS myself to make a suggestion.)
I will mention that "3" is not a very meaningful value for jobOfferStatus, and there's no need for the client to know that number. You can make it anything you want -- jobOfferStatus=none or even jobOffer=none. Your controller can do the work of matching that value to your enumeration. Try to design your interface to be intuitive for developers (and, of course, write good documentation).
To handle multiple query parameters, you can use optional parameters in your function:
public HttpResponseMessage GetStudents(string jobOffer = "",
string other1 = "",
string other2 = "")
{
if (jobOffer == "accepted" && other2 == "whatever") {
// return a response
}
else {
// return a different response
}
}
When the client uses parameters by those names, you can tailor your response appropriately.
You have some options to do this, let's try to help:
1) Configure a generic route to asp.net web api knows how to solve another action's name different from Get to a get method, on the App_Start\WebConfigApi.cs class, try to add this:
config.Routes.MapHttpRoute("DefaultApiWithActionAndId",
"api/{controller}/{action}/{id}",
new { id = RouteParameter.Optional });
Using it, you can have diferent methods on the api controller:
// request: get
// url: api/Students/GetStudents
public HttpResponseMessage GetStudents()
{
return Request.CreateResponse(...);
}
// request: get
// url: api/Students/GetStudentsWithJobOffer
public HttpResponseMessage GetStudentsWithJobOffer()
{
return Request.CreateResponse(...);
}
// request: get
// url: api/Students/GetStudentsAcceptedJob
public HttpResponseMessage GetStudentsAcceptedJob()
{
return Request.CreateResponse(...);
}
2) Use a simple parameter on the Get method:
// request: get
// url: api/Students?jobOfferStatus=1
public HttpResponseMessage GetStudents(int jobOfferStatus)
{
// use jobOfferStatus parameter to fill some list
return Request.CreateResponse(...);
}
3) Use a simple method with a parameter named id, to get a default friendly url by asp.net mvc web api.
// request: get
// url: api/Students/1
public HttpResponseMessage GetStudents(int id)
{
// use the id parameter to fill some list
return Request.CreateResponse(...);
}