Is there a way to access empty fields of a Target entity in the preoperation stage when it has not been populated by the user?
The short answer is no.
Target only contains attributes whose values were changed or deleted.
Images only contain attributes that were chosen in Plugin Registration Tool. But they still do not contain attributes with NULL values.
If you tell us more about your development, maybe we could suggest something else.
You can access field by Entity.Contains() and Entity.GetAttributeValue<T>(). If field has not been populated, Entity.Contains() will return a false and Entity.GetAttributeValue<T>() will return a default(T).
Example:
// Entity.Contains(), use this to judge if entity contains a certains field.
if (targetEntity.Contains("yourfiledname"))
{
var field = targetEntity.GetAttributeValue<string>("yourfiledname");
if (string.IsNullOrEmpty(field))
{
// do your logic
}
}
// Entity.GetAttributeValue<T>() this return a T or default(T).
var optionsetField = targetEntity.GetAttributeValue<OptionSetValue>("someoptionsetfield");
if (optionsetField != null)
{
// do your logic
}
Related
I've overridden a a record value like the following :
public function getWeightAttribute($weight)
{
if($weight)
{
return $weight;
}
return 70;
}
Now I have a collection of that model and I want to know if the original value was null or not.
I want to do it without connecting to DB again, Actually I want to make sure the user has filled the weight and some other fields while registering.
Some sections are working based on the above override and I don't want to mess them up neither use extra connections to db.
Thanks In Advance,
In order to get the original value, you can use:-
$fetchData->getAttributes()['weight'];
Right now, if I add a field to a Parse object and then save it, the new column shows up in the Parse dashboard.
For example, after running:
let media = new Parse.Object("Media");
media.set("foo", "bar");
await media.save();
I will have a new column called foo.
Is it possible to prevent this from happening?
Yes. This can be done using class-level permissions, which allow you to prevent fields being added to classes.
Parse lets you specify what operations are allowed per class. This lets you restrict the ways in which clients can access or modify your classes.
...
Add fields: Parse classes have schemas that are inferred when objects are created. While you’re developing your app, this is great, because you can add a new field to your object without having to make any changes on the backend. But once you ship your app, it’s very rare to need to add new fields to your classes automatically. You should pretty much always turn off this permission for all of your classes when you submit your app to the public.
You would have to add a beforeSave trigger for every one of your classes, keep a schema of all your keys, iterate over the request.object's keys, and see if there are any that do not belong in your schema. You can then either un-set them and call response.success(), or you can call response.error() to block the save entirely, preferably with a message indicating the offending field(s).
const approvedFields = ["field1", "field2", "field3"];
Parse.Cloud.beforeSave("MyClass", function(request, response) {
let object = request.object;
for( var key in object.dirtyKeys() ) {
if( approviedFields.indexOf(key) == -1 ) return response.error(`Error: Attempt to save invalid field: ${key});
}
response.success();
});
Edit:
Since this got a little attention, I thought I'd add that you can get the current schema of your class. From the docs: https://docs.parseplatform.org/js/guide/#schema
// create an instance to manage your class
const mySchema = new Parse.Schema('MyClass');
// gets the current schema data
mySchema.get();
It's not clear if that's async or not (you'll have to test yourself, feel free to comment update the answer once you know!)
However, once you have the schema, it has a fields property, which is an object. Check the link for what those look like.
You could validate an object by iterating over it's keys, and seeing if the schema.fields has that property:
Parse.Cloud.beforeSave('MyClass', (request, response) => {
let object = request.object;
for( var key in object.dirtyKeys() ) {
if( !schema.fields.hasOwnProperty(key) ) < Unset or return error >
}
response.success();
}
And an obligatory note for anyone just starting with Parse-Server on the latest version ,the request scheme has changed to no longer use a response object. You just return the result. So, keep that in mind.
all.
I have following simple form in which I want to edit the entity. The problem is that I have some fields which I don't want to be edited. For example (Image file path).
As it is now, I have the service method -
public void addOrModifyLayout(Layout layout){
if(layout.getId() == null){
layoutRepository.save(layout);
}
else {
Layout modifiedLayout = new Layout();
modifiedLayout.setId(layout.getId());
modifiedLayout.setName(layout.getName());
modifiedLayout.setStatus(layout.getStatus());
modifiedLayout.setExhibitor(layout.getExhibitor());
layoutRepository.save(modifiedLayout);
}
}
As you can see, every field that I want to be able to be edited, I should explicitly put it in the service. Can I use some mapper or trick to update only some fields that are in the view (form) ? How you handle this kind of issues?
You can either
store all the entity fields in hidden inputs (e.g. imageFilePath hidden input). So you can store on UI all the entity fields and get them back to assign to the entity.
OR
Avoid new entity creation but retrieve existing one and fill only necessary fields.
Layout modifiedLayout = layoutRepository.getById(layout.getId());
modifiedLayout.setName(layout.getName());
modifiedLayout.setStatus(layout.getStatus());
modifiedLayout.setExhibitor(layout.getExhibitor());
layoutRepository.save(modifiedLayout);
I am trying to accomplish the following:
I have a form that starts with a combo box, let's say that the user will have to pick either "Student" or "Teacher".
Both "Student" and "Teacher" will have the same fields displayed in the form, but if "Teacher" is checked, I will have more fields being displayed (that are hidden at first and that I will show with jQuery when the user select "Teacher").
The problem is that I want those fields to be mandatory only if "Teacher" is selected.
I have no idea to manage that, I don't think it's gonna be possible using annotations such as:
#NotBlank
private String teacherCourse;
since this field will always be blank when the user will have selected the "Student" radio button.
Any idea? Can I do a custom validation method and how?
I've taken two approaches with this in the past.
Use an enum field on the submission to determine which type of validation to perform. This is flexible and allows for any number of custom validation methods.
An alternative is to use a base command object which both student and teacher classes extend. This allows both types to extend and override validation and fields. This requires that separate methods are used to bind each type.
You could use validation groups to differentiate between constraints applying to both entities and those applying to only one of them:
public interface TeacherConstraints {}
#NotBlank(groups=TeacherConstraints.class)
private String teacherCourse;
When validating your object, specify the group to validate depending on the type selected in your combo box:
//teacher
Set<ConstraintViolation<Object>> violations = validator.validate(object, TeacherConstraints.class);
//student
Set<ConstraintViolation<Object>> violations = validator.validate(object, Default.class);
You can use javascript or JQuery for front side validation... depending upon your combo box value. If it's a teacher or student
function validate(){
var combox_value = document.getElementbyID("combo_box").value;
if(combox_value == "Teacher"){
//Validate for Teacher fields
var input_text1 = document.getElementbyID("input_text"2).value;
if(input_text1=="" || input_text1==null){
alert("Field cannot be empty");
return false;
}
return true;
}
else if(combox_value == "Student"){
//Validate for Student fields
var input_text2 = document.getElementbyID("input_text2").value;
if(input_text2=="" || input_text2==null){
alert("Field cannot be empty");
return false;
}
return true;
}
}
For JQuery try these links for live examples...
http://speckyboy.com/2009/12/17/10-useful-jquery-form-validation-techniques-and-tutorials-2/
http://www.jeasyui.com/tutorial/form/form3.php
http://www.camcloud.com/blog/jquery-form-validation-tutorial
Using ASP.NET MVC when I create my model, then a controller based on the model with CRUD operations, the CRUD views are generated. I added some code using Fluent API to require certain fields but for some reason the ModelState.IsValid passes even when these fields are not completed. What determines whether this passes or not? I thought it was based on your model property data types and other things like being required or maxlength, etc....
Also, I have manually added code to grab a list of Categories from the database and generate a checkbox for each one in the View. This is a navigation property for the Project model where there is a many-many relationship. To get the group of checked values in the Create(Project project) method in the controller I use:
var selected = Request["categories"].Split(',');
This however, throws the classic Object reference not set to an instance of an object error if no values are checked. So what I want to know is, how can I determine that this does not have any values so I can do something else once detected?
I added some code using Fluent API to require certain fields but for
some reason the ModelState.IsValid passes even when these fields are
not completed.
ASP.NET MVC doesn't know anything about the Fluent API of Entity Framework and doesn't evaluate this configuration. You only can use the data annotations which MVC will recognize:
[Required]
public string SomeProperty { get; set; }
...how can I determine that this does not have any values so I can do
something else once detected?
Not sure if I understand it correctly but I'd say:
var categories = Request["categories"];
if (categories != null)
{
var selected = categories.Split(',');
// ...
}
else
{
// do something else
}