Lately i've face problem of nested objects posting. After researched the proper solution involving either views create() implementation or separate serializers for reading and writing with create() method overriten.
I post with axios, and my object looks like this:
{
comment: str
priority: str
file: int // -> this one is ForeignKey for another object and needs its PK which is ID
}
The way i want to have my post data structured is:
{
comment: str
priority: str
file: str // -> which is file object name
}
After sending this request DRF should look in db for file on this name and place its id in this filed.
Is this the proper way ? Or should i nest whole object instead of just its id ?
Another question, offtopic: what is called first after request: serializer or view ?
You can use SlugRelatedField in your serializer
file = serializers.SlugRelatedField(
slug_field='name'
)
But name field of your model should be unique=True
Related
When you generate grails views, grails looks at your relationships and generates the right html for your form data to be automatically binded to the back end domain. For one to one associations grails creates a drop down list.
However, you might not want to present that property as a drop down list but something more custom (for example a text field with autocomplete). As soon as you do that the value that comes to the controller from that field, comes in as a String and you have to first:
Clear errors
Perform a findBy based on a given param and assign it to the property of the domain
I really want to avoid doing findBys in the controller as much as possible because it seems like I am doing logic/things that should not go there. The controller should delegate to the Service layer. It is not clear to me from the grails documentation how would I do that by using bindData which seems to work really well with String, date, Integer properties etc.. but I do not see how bindData is used for properties that are other domains.
I also really want to avoid passing the params object to the Service layer as it seems less reusable (or maybe not, correct me if I am wrong). I guess that I do not like how it looks semantically. I would prefer the first over the second:
#Transactional
class WithdrawService {
def addWithdraw(Withdraw withdraw) {
//perform business logic here
}
def createWithdraw(Map params){
//perform business logic here
}
}
Let's take the following example:
class Withdraw {
Person person
Date withdrawDate
}
and the parent lookup table
class Person {
String name
String lastName
static constraints = {
}
#Override
public String toString() {
return "$name $lastName"
}
}
In order for the bind to happen automatically without any extra work grails passes in the following request params to automatically bind the one to one:
person.id
a person map with the id.
[person.id:2, person:[id:2], withdrawDate:date.struct, withdrawDate_month:11, create:Create, withdrawDate_year:2015, withdrawDate_day:10, action:save, format:null, controller:withdraw]
What is the best way to go about this?
Pass two hidden fields that look exactly like this: person.id:2, person:[id:2] that get populated as a result of the Ajax call that populates the autocomplete?
In the controller do a Person.findBySomeKnownProperty(params.someKnownValue)
Or any other approach?
I am new in mvc so forgive me if the question is stupid but I want to do the best I can. So, my situation is that:
I have created a model and decorated like
Partial Public Class App_Modules
<Required>
<Remote("CheckForDuplicate", "Validation")>
<Display(Name:="Code")>
Public Property code As String
<Required>
<Display(Name:="Description")>
Public Property name As String
End Class
As you can see, the code column must be remote validated.
In my ValidationController I have the code
Public Function CheckForDuplicate(code As String) As JsonResult
Dim data = db.App_Modules.Where(Function(p) p.code.Equals(code, StringComparison.CurrentCultureIgnoreCase)).FirstOrDefault()
If data IsNot Nothing Then
Return Json("This code already exists",JsonRequestBehavior.AllowGet)
Else
Return Json(True, JsonRequestBehavior.AllowGet)
End If
End Function
End Class
Everything works fine! Now I want to do the same for another model with the same field "code". Is there any way to pass the model name to the function so instead of the line
Dim data = db.**App_Modules**.Where(Function(p) p.code.Equals(code, StringComparison.CurrentCultureIgnoreCase)).FirstOrDefault()
I could have something like
Dim data = db.**TABLENAME**.Where(Function(p) p.code.Equals(code, StringComparison.CurrentCultureIgnoreCase)).FirstOrDefault()
So the function would be generic and can be called from other models too?
I am not sure of the syntax in VB but you could modify your CheckForDuplicate function to accept a generic parameter that represents your Model class and pass that to the Set function of your DBContext. you will also need to define an interface for your Model that contains the Code property. Sample code in c# is as follows.
public JsonResult CheckForDuplicate<T>(string code) where T : IModelWithCode
{
var data = db.Set<T>().Where(t => t.Code.Equals(code));
....
}
public interface IModelWithCode
{
string Code { get; set; }
}
Hopefully that will get you started in the right direction.
I don't think this can be done or at least easily.
I would stick with the simple here: create a Select Case and check in the tables depending on the parameter passed (model name).
Dim exist = false;
Select Case myModel
Case "Model1"
exist = db.Model1Table.Where(Function(p) p.code.Equals(code, StringComparison.CurrentCultureIgnoreCase)).Any()
Case "Model2"
exist = db.Model2Table.Where(Function(p) p.code.Equals(code, StringComparison.CurrentCultureIgnoreCase)).Any()
End Select
If each table has different layout or you have to do some other checks... you are free to do the special thing in each case.
UPDATE:
Here you can see an article showing how to pass other fields to the validator action.
You should create a Hidden Field to hold the Model name.
http://www.codeproject.com/Articles/674288/Remote-Validation-in-MVC-Simple-Way-to-Pass-the-F
Other resource: MVC Remote Attribute Additional Fields
This is driving me crazy. I'm using ASP.NET MVC. I have a controller with an HttpPost action that acts as a callback URL that is called by another server (not under my control). I want to dynamically read JSON posted to it without using WebAPI or Model Binding. The URL also has a query string parameter passed to it.
The callback URL looks something like this:
http://domain.com/callback?secret=1234
I've tried reading the posted input using:
[HttpPost]
public ActionResult Callback( String secret )
{
String jsonData = new StreamReader(this.Request.InputStream).ReadToEnd();
// ...
}
However "jsonData" is always null or empty.
I just want to get the posted input and stick it into JsonFx so I can dynamically access the contents. Any ideas on how to do this the easiest possible way?
UPDATE
I've discovered the following ...
While the above DOES NOT work (jsonData will be null or empty), the following DOES if I configure what little options I have on the calling server so as to omit the "secret" query string parameter, which is about all I can do on that end since it is not my server. In this case, jsonData will have the correct posted JSON string:
[HttpPost]
public ActionResult Callback( /* String secret */ )
{
String jsonData = new StreamReader(this.Request.InputStream).ReadToEnd();
// ...
}
This is very frustrating to work around and I don't know an easy way to accept both a query string and posted JSON data on a standard MVC controller.
I have a "callback controller" with Action methods that accept various data (via GET, via form POST, via JSON POST, via JSON POST w/ a Query String, etc.) from different third-party servers. These are merchant-type callbacks where I have no control over the formats or methods used to convey information. I just need to accept the callbacks and process the information that should be there.
All of it works fine in my Controller, except the case of "JSON POST w/ a Query String".
This appears (at least to me) to be a shortcoming in standard ASP.NET MVC controllers. ???
Can anyone suggest a solution to this that can be used in a standard ASP.NET MVC controller?
Your initial approach should work if you take into consideration the fact, that ASP.NET MVC model binding has already read the stream, so you should rewind it:
[HttpPost]
public ActionResult Callback(string secret)
{
Request.InputStream.Seek(0, SeekOrigin.Begin);
string jsonData = new StreamReader(Request.InputStream).ReadToEnd();
// ...
}
Reset the position to Zero before reading the stream.
Request.InputStream.Position = 0
For ASP.NET Core 2，this works for me.
[HttpPost]
public ActionResult RawTest() {
using (StreamReader reader = new StreamReader(Request.Body, Encoding.UTF8))
{
string content = reader.ReadToEndAsync().Result;
//...
}
//...
}
So I have a class with a property like this:
public class Foo
{
[Column("GBBRSH")
public static string Gibberish { get; set;}
....
}
For saving data, I have it configured so that the update/insert statements use a custom function:
public static string GetTableColumnName(PropertyInfo property)
{
var type = typeof(ColumnAttribute);
var prop = property.GetCustomAttributes(type, false);
if (propr.Count() > 0)
return ((ColumnAttribute)prop.First()).Name;
return property.Name;
}
This handles fine, but I noticed that when I go to retrieve the data, it isn't actually pulling data back via the function for this particular column. I noticed that the other data present was pulled, but the column in question was the only field with data that didn't retrieve.
1) Is there a way to perhaps use the GetTableColumnName function for the retrieval part of Dapper?
2) Is there a way to force Dapper.NET to throw an exception if a scenario like this happens? I really don't want to have a false sense of security that everything is working as expected when it actually isn't (I get that I'm using mapping that Dapper.NET doesn't use by default, but I do want to set it up in that manner).
edit:
I'm looking in the SqlMapper source of Dapper and found:
private static IEnumerable<T> QueryInternal<T>(params) // my knowledge of generics is limited, but how does this work without a where T : object?
{
...
while (reader.Read())
{
yield return (T)func(reader);
}
...
}
so I learned about two things after finding this. Read up on Func and read up on yield (never used either before). My guess is that I need to pass reader.Read() to another function (that checks against column headers and inserts into objects appropriately) and yield return that?
You could change your select statement to work with aliases like "SELECT [Column("GBBRSH")] AS Gibberish" and provide a mapping between the attribute name and the poco property name.
That way, Dapper would fill the matching properties, since it only requires your POCO's to match the exact name of the column.
I needed a domain class that held a list of Strings. It seems fairly well-known that GORM can't handle this, so I've worked around it. At first I tried using getters and setters in the domain class, but that caused problems. Then I found on Stack Overflow a way to use afterLoad() and beforeValidate() to rewrite properties as shown below. This has worked well to allow me to turn the List into a String for persistence and back to a List for use in the app.
class Entries {
// persisted to database
String _entry
// exposed to app
List entry
static transients = ['entry'] //don't try to persist the List
def afterLoad() {
// split the String from the database into a List
entry = _entry?.split('\\|')
}
def beforeValidate() {
// join the List into a String for persisting
_entry = entry.join('|')
}
static constraints = {
_entry maxSize:4000
}
}
This works fine programmatically. The only problem is that the Grails scaffolding can't deal with this, even if I try to enter a pipe-delimited string. I understand the reason why is that the scaffolding creates a form field for _entry, so entry is null when it tries to save the object. And beforeValidate() relies on a List of Strings to work.
I tried to get around this in the controller, by setting params.entry = params._entry, prior to the call to new Entries(params). [I recognize that this is not a perfect solution, but this was my first pass at getting the form working.] And then I added a test in beforeValidate() to set entry = _entry if entry was null. Basically:
EntriesController.groovy:
params.entry = params._entry // I added this line
def entriesInstance = new Entries(params)
Entries.groovy:
def beforeValidate() {
if( entry == null ) entry = _entry // I added this line
_entry = entry.join('|')
}
I thought that would allow me to enter pipe-delimited strings into the scaffolded Create Entries form and get something into the database.
To my surprise, though, I found that both entry and _entry were null in beforeValidate(), even though I printed and verified that params contained both keys in the controller. I don't understand why this happens. How did my adding a new key to params result in nulls arriving in the domain class?
The follow-up question is, of course, what's the right way to make the scaffolded Create Entries form accept a pipe-delimited String that makes it into the database?
I needed a domain class that held a list of Strings. It seems fairly well-known that GORM can't handle this, so I've worked around it.
I don't agree with you here
class Xyz {
static hasMany = [entries: String]
}
Should create a seperate table to hold your list of strings (It will actually be a Set). Here are the docs