Lets say I create a slot in Rasa called "yearlybill".
I will have to write:
slots:
yearlybill:
type: float
min_value: 0
So my question is, when I want to use these slot in my intents, will I have to explicitly mention it as an entity as well? Or is that option?
Let's start with a bit of background.
A slot should be seen as a long-term memory slot. You can store information in there manually, via a custom action, without having an entity around.
An entity is a substring of the user message that you'd like to extract for later use. Common entities are names, dates, and product-ids. It's very common to store the entity in a slot, but you don't have to. You can also detect an entity and have a custom action retrieve that information from the tracker.
You could define a slot without defining an entity. If you're planning to use a custom action to fetch the slot value from a users' text, you technically don't need an entity. This isn't a common pattern though. Typically you'd like a specific entity detection model to fetch the entity so that it can be stored in the slot after. That's why it's common to see domain.yml files that contain both a slot and an entity definition.
Related
Theoretically when using event sourcing you don't store "state" but events. But I saw in many implementations that you store snapshots of state in a column in a format like JSON or just a BLOB. For example:
Using an RDBMS as event sourcing storage
The events table has Data column which stores entire object. To me, it's like storing state for that given time when some event occurred.
Also this picture(taken from Streamstone):
It has Data column with a serialized state. So it stores state too but inside an Event?
So how to replay from the initial state then, If I can simply pick some event and access Data to get the state directly.
What exactly is stored inside Data, is it a state of the entire object or it's serialized event?
Let's say I have a person object (in C#)
public class Person
{
public string Name { get; set }
public int Age { get; set; }
}
What should my event store when I create a person or change properties like name or age.
When I create a Person I most likely will send something like PersonCreatedEvent with the initial state, so the entire object.
But what if I change Name or Age should they be 2 separate events or just 1? PersonChangedEvent or PersonChangedAgeEvent and PersonChangedNameEvent?
What should be stored in the event in this case?
What exactly is stored inside Data, is it a state of the entire object or it's serialized event?
That will usually be a serialized representation of the event.
One way of thinking about it: a stream of events is analogous to a stream of patch documents. Current state is calculated by starting from some known default state and then applying each patch in turn -- aka a "fold". Previous states can be recovered by choosing a point somewhere in the stream, and applying the patches up to that point.
The semantics of events, unlike patches, tends to be domain specific. So Checked-In, Checked-Out rather than Patched, Patched.
We normally keep the events compact - you won't normally record state that hasn't changed.
Within your domain specific event language, the semantics of a field in an event may be "replace" -- for example, when recording a change of a Name, we probably just store the entire new name. In other cases, it may make sense to "aggregate" instead -- with something like an account balance, you might record credits and debits leaving the balance to be derived, or you might update the total balance (like a gauge).
In most mature domains (banking, accounting), the domain language has semantics for recording changes, rather than levels. We write new entries into the ledger, we write new entries into the checkbook register, we read completed and pending transactions in our account statement.
But what if I change Name or Age should they be 2 separate events or just 1? PersonChangedEvent or PersonChangedAgeEvent and PersonChangedNameEvent?
It depends.
There's nothing wrong with having more than one event produced by a transaction.
There's nothing wrong with having a single event schema, that can be re-used in a number of ways.
There's nothing wrong with having more than one kind of event that changes the same field(s). NameLegallyChanged and SpellingErrorCorrected may be an interesting distinction to the business.
Many of the same concerns that motivate task based UIs apply to the design of your event schema.
It still seems to me like PersonChangedEvent will contain all person properties that can change. Even if they didn't change
In messaging (and event design takes a lot of lessons from message design), we often design our schema with optional fields. So the event schema can be super flexible, while any individual representation of an event would be compact (limited to only the information of interest).
To answer your question, an event that is stored should be the event data only. Not the objects state.
When you need to work on your Entity, you read up all the events and apply them to get the latest state every time. So events should be stored with the events data only. (ofc together with AggregateId, Version etc)
The "Objects State" will be the computation of all events, but if you have an Eventlistener that listens to all your published events you can populates a separate ReadModel for you. To query against and use as read only from a users perspective.
Hope it helps!
Updated answer to updated question:
Really depends on your model, if you do the update at the same time Age and Name, yes the new age and name values should be stored in a new event.
The event should only contain this data "name and age with aggregateId, version etc"
The event listener will listen specifically on each event (created, updated etc), find the aggregates read model that you have stored and only update these 2 properties (in this example).
For createevent you create the object for the read model.
I have an entity - EntityZ, which has a ParentId where ParentId could be EntityA.Id, EntityB.Id or EntityC.Id. Is it possible to create this in MS Dynamics CRM 2016? If yes, how? I've looked but couldn't find a similar question or any help on the web.
An entity can be the child party in only one full parental relationship. When you are looking for a way to cascade record ownership, deletion a.o. between mutiple parent - child entities you can create configurable cascading relationships.
As Arun Vinoth pointed out you can design your entity as an activity type. However, this may conflict with the semantics of activity records in CRM. Also, doing this would make it possible to associate the child entity to any entity that is enabled for activities.
There’s a trade off to achieve this. Custom entity as Custom Activity
Creating custom entity EntityZ as custom activity and EntityA, B, C can act as parent.
EntityA or B or C can be chosen as RegardingObjectId of EntityZ.
This has security limitation like EntityZ will be visible to everyone as this will be listed like other activities (Email, Phonecall, Task, etc)
I think it is worth nothing that Dynamics 365 does contain and out-of-box "polymorphic" customer field.
This field can link to either an Account or Contact:
And while it can be kludgy, another option would be to create 3 lookups and only populate one. Once one is populated you could hide the other two. Or, you could have a "Parent Type" option set to determine which lookup to show.
It would be a bit messy to show three lookups in a view, with only one populated, so you might also want a Parent Name text field in to which you could concatenate the type and name. You could use a workflow to populate it, and then use it in views and reports.
I am working on a MVC3 code first web application and after I showed the first version to my bosses, they suggested they will need a 'spare' (spare like in something that's not yet defined and we will use it just in case we will need it) attribute in the Employee model.
My intention is to find a way to give them the ability to add as many attributes to the models as they will need. Obviously I don't want them to get their hands on the code and modify it, then deploy it again (I know I didn't mention about the database, that will be another problem). I want a solution that has the ability to add new attributes 'on the fly'.
Do any of you had similar requests and if you had what solution did you find/implement?
I haven't had such a request, but I can imagine a way to get what you want.
I assume you use the Entity Framework, because of your tag.
Let's say we have a class Employee that we want to be extendable. We can give this class a dictionary of strings where the key-type is string, too. Then you can easily add more properties to every employee.
For saving this structure to the database you would need two tables. One that holds the employees and one that holds the properties. Where the properties-table has a foreign-key targeting the employee-table.
Or as suggested in this Q&A (EF Code First - Map Dictionary or custom type as an nvarchar): you can save the contents of the dictionary as XML in one column of the employee table.
This is only one suggestion and it would be nice to know how you solved this.
I'm just looking for a bit of clarity on the correct way to model custom entities and activities in CRM 2011.
I have to model a custom activity which is called a Submission. It is really just a Case with some additional properties.
When creating this in my Solution, is it best practice to base it on the Case Entity and then add the properties, or would it be better to create a new activity instead?
We have other types of activities which are similar, so I would also be basing them on the Case entity if that's the best way to go.
Many thanks,
John
I usually err on the side of creating a new custom entity (or activity), especially if you think you might have "case types" that are significantly different. It isn't fun writing a bunch of javascript that shows/hides fields based on type.
You might pick the one activity type (perhaps Submission) that is most like a "Case" and then create custom activities for the others that are close. But then you'll have subtle differences (the Customer lookup on Case, for example, can be either a Contact or Account, but you can't add your own "Customer" lookup to your custom entities).
Unless you really need something that the built-in Case entity provides that you can't do yourself, my vote would be for new entities (activities) and then just hide the built-in Case entity by security roles.
I've made a custom entity that will work as an data modification audit (any entity modified will trigger creating an instance of this entity). So far I have the plugin working fine (tracking old and new versions of properties changed).
I'd like to also keep track of what entity this is related to. At first I added a N:1 from DataHistory to Task (eg.) and I can indeed link back to the original task (via a "new_tasksid" attribute I added to DataHistory).
The problem is every entity I want to log will need a separate attribute id (and an additional entry in the form!)
Looking at how phone, task, etc utilize a "regardingobjectid", this is what I should do. Unfortunately, when I try to add a "dataobjectid" and map it to eg Task and PhoneCall, it complains (on the second save), that the reference needs to be unique. How does the CRM get around this and can I emulate it?
You could create your generic "dataobjectid" field, but make it a text field and store the guid of the object there. You would lose the native grids for looking at the audit records, and you wouldn't be able to join these entities through advanced find, fetch or query expressions, but if that's not important, then you can whip up an ASPX page that displays the audit logs for that record in whatever format you choose and avoid making new relationships for every entity you want to audit.
CRM has a special lookup type that can lookup to many entity types. That functionality isn't available to us customizers, unfortunately. Your best bet is to add each relationship that could be regarding and hide the lookups that aren't in use for this particular entity.