Is there a way to add Validation to a property on my VM "dynamically" (i.e. sometime after I register the initial rules on the VM)?
Currently, I'm registering the rules in the constructor of the VM, then a little while later, after the user has entered a bunch of data, I need to show a new field (using if.bind) and want to add validation depending on the result of a web api call..
Wondering if there's an API for this that I've missed?
You can achieve it without dynamically adding rule but instead you can use satisfiesRule and when, see it here in section Conditional Validation. satisfiesRule will only evaluated if the property that attached to it is already pass.
when will only evaluated the rule if the condition is true.
Additional link.
If you're using bootstrap, you can find this useful.
Related
I spent almost a full day debugging why my client can't post any forms, until I found out the anti-forgery mechanism got borked on the client-side and the server just responded with a 400 error, with zero logs or information (turns out anti-forgery validation is logged internally with Info level).
So I decided the server needs to special handle this scenario, however according to this answer I don't really know how to do that (aside from hacking).
Normally I would set up a IAlwaysRunResultFilter and check for IAntiforgeryValidationFailedResult. Easy.
Except that I use Api Controllers, so by default all results get transformed into ProblemDetails. So context.Result as mentioned here is always of type ObjectResult. The solution accepted there is to use options.SuppressMapClientErrors = true;, however I want to retain this mapping at the end of the pipeline. But if this option isn't set to true, I have no idea how to intercept the Result in the pipeline before this transformation.
So in my case, I want to do something with the result of the anti-forgery validation as mentioned in the linked post, but after that I want to retain the ProblemDetails transformation. But my question is titled generally, as it is about executing filters before the aforementioned client mapping filter.
Through hacking I am able to achieve what I want. If we take a look at the source code, we can see that the filter I want to precede has an order of -2000. So if I register my global filter like this o.Filters.Add(typeof(MyResultFilter), -2001);, then the filter shown here correctly executes before ClientErrorResultFilter and thus I can handle the result and retain the transformation after the handling. However I feel like this is just exploiting the open-source-ness of .Net 6 and of course as you can see it's an internal constant, so I have no guarantee the next patch doesn't change it and my code breaks. Surely there must be a proper way to order my filter to run before the api transform.
This is about an API handling the validation during saving an object. Which means that the front-end client sends a request to the API to a specific end point, then on the back-end the API creates a new object if the right conditions are meet.
Right now the regular method that we use is that the models has a ruleset for each fields and then the validation is invoked when the save function is invoked, but technically the validation is done right before the object is saved into the database.
Then during today's code review I came across a solution which I wasn't sure if it's a good practice or not. And it was about that the front-end must send a specific parameter to the API every time. This is because other APIs are using our API as well, and we needed to know if the request was sent as and API request or a browser request. If this parameter is present then we want to execute an extra validation function on a specific field.
(1)If I would have to implement it, then I would check the incoming parameter in the service handler or in the controller level, and if I got one, I would invoke the validation right away, and if it fails I would throw an error.
(2)The implementation I saw however adds an extra variable to the model, and sets the model variable when there is an incoming parameter, then validates only when the save function is invoked on the object(which first validates the ruleset defined on the object fields, then saves the object into the database)
So my problem with (2) is that the object now grown bigger with an extra variable that is only related to a specific event. So I would say it's better to implement (1). But (2) also has an advantage, and that is when you create the object on different end point by parsing the parameters, then the validation will work there as well, even if the developer forget to update the code there.
Now this may seems like a silly question because, why would I care about just 1 extra variable, but this is like a bedrock of something good or bad. So if I say this is ok, then from now on the models will start growing with extra variables that are only related to specific events, which I think should be handled on the controller/service handler level. On the other hand the code would be more reliable if it's not the developer who should remember all the 6712537 functionalities and keep them in mind when makes some changes somewhere. Let's say all the devs will get heart attack tomorrow from the excitement of an amazing discovery, and a new developer has to work on the project while he doesn't know about these small details, and then he has to change something on the code that is related to this functionality - so that new feature should be supported by this old one as well.
So my question is if is there any good practice on this, and what do you think what would be the best approach?
So I spent some time on thinking on the solution, and I think the best is to have an array of acceptable trigger variables in the model class. Then when the parameters are passed to the model on the controller level, then the loader function can be modified that it takes the trigger variables from the parameters and save it in the model's associative array variable that stores the trigger variables.
By default this array is empty, and it doesn't matter how much new variables are needed to be created, it will only contain the necessary ones when those are used.
Then of course the loader function needs to be modified in a way that it can filter out the non trigger variables as well as it is done for the regular fields, and there can be even a rule set of validation on the trigger variables if necessary.
So this solves the problem with overgrowing the object with unnecessary variables and the centralized validation part, because now the validation can be always done in the model instead of the controller.
And since the loader function is modified to store the trigger variables in the model's trigger variables array variable, the developer never has to remember that this functionality was created. Which is good, because in the future when he creates a new related function or end point that should handle object creation, he will not miss it to validate it against the old functionality, because the the loader function that he modified in the past like this will handle it for him.
It needs to be noted tho, that since the loader function doesn't differentiate between the parameters, and where to load them other then checking the names of the parameters with the filter functions, these parameter names should be identical from each other, otherwise a buggy functionality can be created accidentally. Like if you forget that a model attribute with the same name was used, then you can accidentally trigger an event that was programmed to be triggered if the trigger variable with the same name is present. However this can be solved by prefixing the trigger variables for example.
I am developing rest api update method for user profile resource user/profile. I am disappointed what http method should i use. Update contains some required attributes so it more PUT request, where client need to fill all attributes. But how it can extend attributes in future. If i will decide to add new attribute then it will automatically clear because client is not implement it yet.
But what if this new attribute has default value or is set by another route?
Can i use PUT with not stricting number of attributes and use old data if new isn't come in request. Or how it can be done normally?
HTTP is an application whose application domain is the transfer of documents over a network -- Webber, 2011.
PUT is the appropriate method to use when "saving" a new version of a document onto a web server.
how it can extend attributes in future.
You design your schemas to be forward and backward compatible; in practice, what this means is that you can add new optional elements with reasonable default values. When you need to add a new required element, you change the name of the schema.
You'll find prior art in this topic by searching XML literature for must ignore.
You understand correctly: PUT is for complete replacement, so values that you don't include would be lost.
Instead, use the PATCH method, which is for making partial updates. You can update only the properties you include values for.
GUI mode is interesting.
At this moment I create one component (i.e. assertion) and then copy and paste it on every place where it's needed. But if I change assertion in some place I must manually change all same assertions in all other places where its used.
Reusability in Jmeter can be done in 4 ways:
include controller when you want to reuse a subset of test (login, logout)
module controller to reuse controller in existing plan
user defined variables that you can reuse everwhere
xxx defaults for some samplers ( Ftp, Http...)
But in your particular case you can do it as below.
Define your expression as a var in User Defined Variable then use it in your assertions:
http://jmeter.apache.org/usermanual/component_reference.html#User_Defined_Variables
For sampler use Http Request Defaults to factor what is common between them.
http://jmeter.apache.org/usermanual/component_reference.html#HTTP_Request_Defaults
Note that to find elements with same regexp expression yoy can use search feature which highlights results of search.
IMHO The cleanest way to reuse components is to use ModuleController with jMeter Plugins' ParametrizedController.
The ParametrizedController link above will explain you how it's done.
My scenario is the following:
I have a workflow (lets call it customActivity1) that do the basic actions for my system. I also have another workflow (customActivity2) that uses customActivity1 and do higher level actions. When I call customActivity1, I must pass on a few parameters, like Boolean or String values. I want to show some of these parameters as a checkbox or combobox (so the developer of customActivity2 can pass on only valid values) and found out that I can do that by setting the argument as PROPERTY (instead of In).
By doing a research, I also found out that you can’t directly use this argument in expressions, so I keep getting errors on my customActivity1.
That said and knowing that I need to narrow what the designer can pass on, how could I do that without using an activity designer or where could I find an answer?
I also attached two pictures, one of what I need and the other of the error I’m getting.
Thanks in advance.
The reason an InArgument only shows you a text field instead of a checkbox is because they are expressions not literal values. There is still type checking though, if you enter the value 1 you get the error message that an integer cannot be converted into a boolean.
You cannot do this. You can only bind to InArguments.
If you bind an InArgument and look at the xaml, you'll see something like this:
<p1:MyActivity MyInArgument="[BoundValue]" ...
The Workflow Runtime knows how to handle these. It doesn't know how to handle binding POCO properties.
If you want to model data flow but want to have a different user experience in the property grid I recommed using arguments (as they convey data flow semantics) and customizing the property grid for those arguments. There is a sample that demonstrates how to do this in the WF4 samples (sample readme available at http://msdn.microsoft.com/en-us/library/ee834515.aspx)