Hey I m using MessageRoutingCallback to route to a function in spring cloud functions. It needs FunctionRoutingResult for routing. I also wanted to edit the message. The spring cloud docs says.
"Additionally, the FunctionRoutingResult provides another constructor allowing you to provide an instance of Message as second argument to be used down stream".
But the problem is the constructor with Message type in FunctionRoutingResult is internal and cannot be accessed outside.
Am I doing something wrong here. Any insight would be helpful
Couple of things.
As the documentation explains it is made to assist with routing decisions. For example if routing decision should be made based on payload which may need to be temporarily converted.
The reality is that it is a very bad practice to let framework make such decisions based on the payload, since payload is a privileged information. Similar to the letter in the envelope where mailman does not read the actual letter to make proper routing decisions. .. those all come from the envelope itself. So I will actually update the documentation to remove that paragraph.
And it is definitely not there to modify the message. That would be improper use of MessageRoutingCallback. To modify message you can use function composition. For example MessageRoutingCallback you check some header in the incoming message, determined that the function name should be foo but then actually output modifier|foo as function definition.
Related
I have $dinetype variable obtained from the user.
But I would like to give response based on what value has been set in $dinetype variable. In addition to giving responses, I also need to set relevant context. How do I do this in DialogFlow?
if($Dinetype=='dineout')
ask ('which restaurant would you like to go to?')
set_context ('awaiting-restaurant')
if($Dinetype=='takeaway')
ask ('When would you like to take away?')
set_context ('awaiting-takeaway-time')
Is it programmable at all? Or is it possible to achieve something equivalent to the above in the UI?
Edit: A much easier way has been added to handle this issue directly in Dialogflow
(Updated Solution) Follow-up Intents:
After creating an intent, you can add follow-up intents now.
Intents -> Create Intent >
[Response=Prompt For Conditional Response]
Intents -> Add Follow-up Intent -> Custom/Yes/No
Then set the training praise to a matching entity you want to conditionally respond to
OLD HACKY SOLUTION:
Late reply, but maybe someone will find this useful.
If the conditional response only needs to reference a single parameter
value, then I figured out what you can do is utilize the Entity's
"Reference Value" as the response you want to give for a particular
set of Synonyms.
So you'd have an entity that looked like this:
Then, setup your intent like this, with a response of $Dinetype:
Then the end result will look like this:
And you can make whatever follow-up intent you need from there.
Down-side is Dinetype won't be as reusable. But I still think it
beats writing a fulfillment webhook every time you need a simple
conditional response.
You can't do this in the Response section directly. The Response section is meant for fairly simple responses that don't require significant logic to process. Although you can use parameters in the response, you can't give a different response based on the value of the parameter. So you can set a response to something like
I think $Dinetype is great food.
but not
{{#if $Dinetype == "Thai"}}I think Thai food is too hot{{/if}}
or anything like that
However, you can add code that sends conditional responses and contexts by implementing a Fulfillment webhook. Although you can't do this for each Intent as part of the Intent editor screen, the Fulfillment screen includes a built-in code editor.
I found a solution to my similar problem using composite entities, which may or may not be overkill for your agent. The value assigned to a parameter associated with the (composite) entity will contain a JSON structure, if a synonym in that entity was matched.
Using the "Dot" notation, you can assign the matched sub-entity's property (similar to the reference value of a normal entity) to another parameter in the Actions and Parameters section. You can have one parameter for each sub-entity and hence, you can evaluate these parameters in your response section to select each response variants:
$Parameter_A ResponseA
$Parameter_B ResonseB
....
etc.
Clunky but works. Just have to be careful to reference the property exactly as it is defined in the composite entity.
I've an OpenDDS node that's both a DataDriver and DataReader. The consequence is that if the node send a topic, the same topic is received from the same node.
Is there a QoS policy that avoid this behaviour? I want that a node can receive the topic from all nodes but itself.
I want that a node can receive the topic from all nodes but itself.
If you are in a situation where your data type for the relevant Topic includes an attribute that contains information about the source of the data, then you can use that attribute to filter on via a ContentFilteredTopic. Suppose that your data type has a field nodeId that identifies your node, then you can use a ContentFilter expression like nodeId <> %0 and set the parameter to your own nodeId. The middleware would deliver all updates to your DataReaders, except for those that have your own nodeId. Check out the DDS specification for more details.
Given that your application wants to ignore data coming from your own node, I would argue that your data type actually needs that nodeId as an attribute, because apparently that is information relevant for your application. So if you do not have it at the moment, you might have to add it.
If you are not allowed or do not want to add such a field your data type, you can also use another, more convoluted mechanism by leveraging the ignore_publication() or ignore_participant() methods. These are explained in the specification as well. If you want to go that route, let me know if you have questions about it.
Finally, there might be vendor-specific extensions to the API that provide you with easier ways to achieve what you are looking for. For example, see How do I get a DataReader to ignore a DataWriter that belongs to the same DomainParticipant? for a solution using the RTI product.
According to http://msdn.microsoft.com/en-us/library/ff823993%28v=VS.85%29.aspx, during this event the web filter can request GUID of the matching rule. I am assuming that is done by performing a GetServerVariable with type of SELECTED_RULE_GUID, since I could find no other readily identifiable means of doing so.
My problem comes from the fact that I want to see if the rule is allowing or blocking the request. If it's being blocked then my filter doesn't have to take any action, but if it's being allowed I need to do some work. SF_NOTIFY_POLICY_CHECK_COMPLETED seems to be the best event to watch, since it occurs last enough that authentication and various ms_auth traffic has been handled, but just before the request either gets routed or fetched from cache.
I had thought that perhaps I needed to use COM and the IFPC interfaces (following along with example code for registering Web Filters to TMG) to get details on the rule. However, going down via FPC -> FPCArray -> FPCArrayPolicy -> FPCPolicyRules, the only element-returning function takes either an index or a name.
Which is problematic given that I only have a GUID.
The FPCPolicyRule object (singular) doesn't seem have any field related to GUID either, which eliminates just iterating over the collection for it.
So my question boils down to, from the SF_NOTIFY_POLICY_CHECK_COMPLETED event, how would a web filter determine if the request has been allowed or denied?
After more investigation and testing, the GUID is accessible via the PersistentName of the FPCPolicyRule object. Since FPCPolicyRules->Item member only works on either Name or Index, I had to iterate through its items comparing each PersistentName against the GUID.
Apologies if this was obvious, took me a good day to work out :)
Coming from a lot of frustrating times with WSDL/Soap, I very much like the REST paradigm, but am trying to solve two basic problems in our application, before moving over to REST. The first problem relates to the lack of an interface document. I think I finally see how to handle this situation: One can query his way down from a top-level "/resources" resource using various requests of GET, HEAD, and OPTIONS to find the one needed resource in the correct hypermedia format. Is this the idea? If so, the client need only be provided with a top-level resource URI: http://www.mywebservicesite.com/mywebservice/resources. He will then have to do some searching and possible keep track of what he is discovering, so that he can use the URIs again efficiently in future to do GETs, POSTs, PUTs, and DELETEs. Are there any thoughts on what should happen here?
The other problem is that we cannot use descriptive URLs like /resources/../customer/Madonna/phonenumber. We do have an implementation of opaque URLs we use in the context of a session, and I'm wondering how opaque URLs might be applied to REST. The general problem is how to keep domain-specific details out of URLs, and still benefit from what REST has to offer.
The other problem is that we cannot use descriptive URLs like /resources/../customer/Madonna/phonenumber.
I think you've misunderstood the point of opaque URIs. The notion of opaque URIs is with respect to clients: A client shall not decipher a URI to guess anything of semantic meaning from it. So a service may well have URIs like /resources/.../customer/Madonna/phonenumber, and that's quite a good idea. The URIs should be treated as opaque by clients: not infer from the URI that it represents Madonna's phone number, and that Madonna is a customer of some sort. That knowledge can only be obtained by looking inside the URI itself, or perhaps by remembering where the URI was discovered.
Edit:
A consequence of this is that navigation should happen by links, not by deconstructing the URI. So if you see /resouces/customer/Madonna/phonenumber (and it actually represents Customer Madonna's phone number) you should have links in that resource to point to the Madonna resource: e.g.
{
"phone_number" : "01-234-56",
"customer_URI": "/resources/customer/Madonna"
}
That's the only way to navigate from a phone number resource to a customer resource. An important aspect is that the server implementation might or might not have domain specific information in the URI, The Madonna record might just as well live somewhere else: /resources/customers/byid/81496237. This is why clients should treat URIs as opaque.
Edit 2:
Another question you have (in the comments) is then how a client, with the required no knowledge of the server's URIs is supposed to be able to find anything. Clients have the following possibilities to find resources:
Provide a search interface. This could be done by providing an OpenSearch description document, which tells clients how to search for items. An OpenSearch template can include several variables, and several endpoints, depending on what you're looking for. So if you have a "customer ID" that's unique, you could have the following template: /customers/byid/{proprietary:customerid}", the customerid element needs to be documented somewhere, inside the proprietary namespace. A client can then know how to use such a template.
Provide a custom form. This implies making a custom media type in which you explicitly define how (based on an instance of the document) a URI to a customer can be forged. <customers template="/customers/byid/{id}"/>. The documentation (for the media type) would have to state that the template attribute must be interpreted as a relative URI after the string substitution "{id}" to an actual customer ID.
Provide links to all resources. Some resources aren't innumerable, so you can simply make a link to each and every one of them, optionally including identifying information along with the links. This could also be done in a custom media type: <customer id="12345" href="/customer/byid/12345"/>.
It should be noted that #1 and #2 are two ways of saying the same thing: Clients are allowed to create URIs if they
haven't got the URI structure a priori
a media type exists for which the documentation states that URIs should be created
This is much the same way as a web browser has no idea of any URI structure on the web, except for the rules laid out in the definition of HTML forms, to add a ? and then all the query parameters separated by &.
In theory, if you have a customer with id 12345, then you could actually dispense with the href, since you could plug the customer id 12345 into #1 or #2. It's more common to actually provide real links between resources, rather than always relying on lookup or search techniques.
I haven't really used web RPC systems (WSDL/Soap), but i think the 'interface document' is there mostly to allow client libraries to create the service API, right? if so, REST shouldn't need it, because the verbs are already defined and don't really need to be documented again.
AFAIUI, the REST way is to document the structure of each resource (usually encoded in XML or JSON). In that document, you'll also have to document the relationship between those resources. In my case, a resource is often a container of other resources (sometimes more than one type), therefore the structure doc specifies what field holds a list of URLs pointing to the contained resources. Ideally, only one unique resource will need a single, fixed (documented) URL. everithing else follows from there.
The URL 'style' is meaningless to the client, since it shouldn't 'construct' an URL. Every URL it needs should be already constructed on a resource field. That let's you change the URL structure without changing the client (that has saved tons of time to me). Your URLs can be as opaque or as descriptive as you like. (personally, i don't like text keys or slugs; my keys are all BIGINTs or UUIDs)
I am currently building a REST "agent" that addresses the first part of your question. The agent offers a temporary bookmarking service. The client code that is interacting with the agent can request that an URL be bookmarked using some identifier. If the client code needs to retrieve that representation again, it simply asks the agent for the url that corresponds to the saved bookmark and then navigates to that bookmark. Currently those bookmarks are not persisted so they only last for the lifetime of the client application, but I have found it a useful mechanism for accessing commonly used resources. E.g. The root representation provides a login link. I bookmark that link and if the client ever receives a 401 then I can redirect to the "login" bookmark.
To address an issue you mentioned in a comment, the agent also has the ability to store retrieved representations in a dictionary. If it becomes necessary to aggregate and manipulate multiple representations at the same time then I can simply request that the agent store the current representation in a dictionary associated to a key and then continue navigating to the next resource. Once the client has accumulated all the necessary representation it can do what it needs to do.
When coding web services, how do you structure your return values? How do you handle error conditions (expected ones and unexpected ones)? If you are returning something simple like an int, do you just return it, or embed it in a more complex object? Do all of the web methods within one service return an instance of a single class, or do you create a custom return value class for each method?
I like the Request/Response object pattern, where you encapsulate your arguments into a single [Operation]Request class, which has simple public properties on it.
Something like AddCustomerRequest, which would return AddCustomerResponse.
The response can include information on the success/failure of the operation, any messages that might be used by the UI, possibly the ID of the customer that was added, for example.
Another good pattern is to make these all derive from a simple IMessage interface, where your general end-point is something like Process(params IMessage[] messages)... this way you can pass in multiple operations in the same web request.
+1 for Ben's answer.
In addition, I suggest considering that the generic response allow for multiple error/warning items, to allow the reply to be as comprehensive and actionable as possible. (Would you want to use a compiler that stopped after the first error message, or one that told you as much as possible?)
If you're using SOAP web services then SOAP faults are the standard way to return error details, where the fault messages can return whatever additional detail you like.
Soap faults are a standard practice where the calling application is a Soap client. There are cases, such as a COM client using XMLHTTP, where the Soap is parsed as XML and Soap faults cannot be easily handled. Can't vote yet but another +1 for #Ben Scheirman.