I am using ASP.NET dynamic data for the data adminstration tasks for a Silverlight app that I built. It saved a ton of time not having to write all of the admin screens you typically have to create for end users to manage the data.
One thing I cannot figure out how to sort the items in the drop downs that appear on the screens - either the filter dropdowns on the list views or on the data entry screens.
Do I specify that somewhere in the EDM partial classes or in the ASP.NET DD field templates? or somewhere else?
All I need to do is sort alphabetically by the display value- they appear to be in random order.
thanks
Michael
Use the DisplayColumn Attribute in the System.ComponentModel.DataAnnotations Namespace.
http://msdn.microsoft.com/en-us/library/system.componentmodel.dataannotations.displaycolumnattribute.aspx
ex:
[DisplayColumn("LastName", "LastName")]
public partial class Employee
{
}
The answer to your question can be found here, about halfway down the page:
http://csharpbits.notaclue.net/2008/08/dynamic-data-and-field-templates-second.html
In the Cascase.ascx.cd FilterControl and Cascade_Edit.ascx.cs FieldTemplate you will find a method GetChildListFilteredByParent. This returns the values for the filtered DropDownList, but as you will see this list is an unordered list. To add sorting to this list we need to add a Linq OrderBy clause.
Related
Let's assume, I have a User model and this model contains products children (one to many relation).
In some situations, in my iOS app, I need only to display list with all users so I don't need to query my database about products.
How to preform, in the easiest way, fetching users without its children in Fluent?
Do I need to create a separate model that doesn't contain products?
func getAllUsersHandler(_ request: Request) -> EventLoopFuture<[User]> {
User.query(on: request.db).all()
}
The default situation is that a query on the User model will not include any Children fields in the result. To include them, you need .with(\.$products) in the query.
You can limit the fields returned by modifying your query as in the example:
User.query(on: request.db).field(\.$name).field(\.$email).all()
This only brings those fields into the model and leaves unwanted fields in an uninitialised state. See here for more information.
I have two tables "Services and Projects". Both tables have a "Name" field. I would like to take both fields from both the tables and put them into a single autocompletebox in one of my screens. I searched around and found different methods of doing this but not in LightSwitch. Any ideas?
If I understand your requirement correctly, you want the Name property from both Services and Projects to appear in a single textbox? If this is the case, my approach would be as follows:
Use a view on the data source to union the Projects and Services data sources
Add that view to your data model (on a new data connection)
Define Name as the summary property for the new view-based entity.
Add the view to your screen as a separate query
Add the view data object to your screen as an auto-complete box.
WARNING: You'll also need code-behind to identify whether the value selected is a Project or a Service and to apply this value to the relevant field in your linked entity.
The objective:
Having a many-to-many relation be displayed as a dynamic list of select inputs(single choice dropdown list)
User arrives on page with a single select field (multiple = false) populated with persisted entities and add/remove buttons. By clicking the add button, a new select field with the same options appears below the first, which adds a new entry in the M2M relation. By clicking remove the field disappears and the entry should be removed.
The model:
Two entities: User & Manager. A User has exactly one "special" Manager and unlimited normal Managers.
Managers manage unlimited users.To model this I have created two relationships for which the user is the "owner" (not sure how to translate this)
ManyToOne specialManager
ManyToMany normalManagers
I haven't created a many to many relationship with attribute "special" because the requirement is exactly one special manager and I wasn't sure if Symfony/Doctrine would cause problems down the line.
What I have:
I can display a multiple select field with the existing entities using Entity field type, as per the documentation. Functionally this is what I need, visually it is not.
I can also use the Collection field type to display a single text field, and add or remove more with JS, as per the documentation. Visually this is what I need, but The text fields (entity attribute) need to be replaced by choice field.
The question:
Before I continue digging, is there a simple way to achieve this list of select tags?
For anyone else who may eventually need a dynamic list of select fields:
I initially solved this issue by detaching the field(s) in event listeners, and handling the display/submission manually in the controller.
However I wasn't satisfied with this clunky solution and when I encountered the same need I used a second solution: creating an intermediary entity xxxChoice (in this case ManagerChoice) which is Mto1 inversed related to User and Mto1 related to Manager. Then by creating a ManagerChoiceType form with "Manager" entity field type I was able to easily display my collection of dropdown select lists.
I have two entities: product and category (Symfony 2.3).
I want to create a form in which an user can choose a product by first selecting the category. A user selects the category by clicking on image, then I want to set the image's value into a hidden input, but I don't see how can I change a foreign entity choice list to a hidden input (http://symfony.com/doc/current/reference/forms/types/entity.html).
How can I accomplish this? (how to change form input to hidden)
If I set cascade validation to true, will it for example check if a category really exist. (To prevent putting products with non-existing category from malicious users) ?
Part 1
To do this you need to use a data transformer to do two things:
transform an entity into an identifier that is either a string or integer so a form can render it as a hidden field.
transform the string or integer identifier into the entity when the form is submitted so that the parent entity can be saved with the correct relationship
The symfony docs I linked to above (here too) actually walk though an entire example of using a data transformer with a form.
As a shameless plug (because I believe it is helpful) I have written a little tutorial on using a data transformer for a hidden field with an entity id: http://lrotherfield.com/blog/symfony2-forms-entity-as-hidden-field/
Part 2
If you are using the data transformer then you don't need to worry about malicious users. The data transformer will fail because it will not be able to reverse transform the category from the fake id. In my tutorial the transformer will throw a Symfony\Component\Form\Exception\TransformationFailedException exception.
You can also write a validator (potentially using a call back) if you wanted that checks that the submitted category is real if you want an error to show in the form. Doctrine wont allow you to persist a fake category relationship as the foreign key constraint will fail.
I have a many-to-many relationship between 2 entities in Entity Framework, like here . So, Employees and Projects. At one point, I would like to insert some Projects to a Employees entity in a specific order. By conserving the order I would like to know which was the first preference of the Employees for a Projects entity. The thing is that although I order the Student.Projectslist in the way I like before the insert, when selecting Employees.Projects.FirstOrDefault(), the entities are ordered after the ProjectsId and I don't get the first element I inserted. How can I conserve the order I want?
O course, I could make a new field PreferredProjects and save the other Projects in a random order, since only the preferred one is important for me. But this is not an option, being given the context of the current project's software design.
Thank you in advance...
It sounds like you simply want to have sorted child collection results when you do a query, rather than take full control of the insert order.
You can achieve that using the techniques described in Tip 1 of my tips series.
Hope this helps.
Alex
Program Manager Entity Framework Team.
Unfortunately, there is no easy solution. I have the same problem. The only solution is to save after adding each child item (project). This is the only way to save the order without using a new field column to sort input.
Try Employees.Projects.OrderBy(x => x).FirstOrDefault()