ewl-page

name	ewl-page
description	Create and configure EWL pages with parameters, URL routing, parent hierarchy, and access control

Creating a page

Every page is a partial class with a // EwlPage comment directive above the class declaration. The Development Utility generates the other partial.

// EwlPage
namespace MySystem.Website;

partial class Home {
	protected override string getResourceName() => "";

	protected override IEnumerable<UrlPattern> getChildUrlPatterns() =>
		RequestDispatchingStatics.GetFrameworkUrlPatterns( WebApplicationNames.Website );

	protected override PageContent getContent() =>
		new UiPageContent().Add( new Paragraph( "Hello!".ToComponents() ) );
}

Use // EwlResource instead of // EwlPage for non-page resources such as file downloads, CSS, or robots.txt.

Run sync after adding or changing any page class.

Page parameters

Declare parameters via comments above the class. The DU generates constructor parameters, URL encoding/decoding, and typed UrlPatterns methods.

// EwlPage
// Parameter: int serviceOrderId

Optional parameters use // OptionalParameter: and can have defaults:

// EwlPage
// Parameter: int organizationId
// OptionalParameter: int? roomId
// OptionalParameter: int calendarViewId

Provide defaults via the generated specifyParameterDefaults partial method:

static partial void specifyParameterDefaults( OptionalParameterSpecifier specifier, Parameters parameters ) {
	specifier.CalendarViewId = CalendarViewsRows.MonthView;
}

Parent pages and URL routing

Every page (except the root) must specify a parent:

protected override ResourceParent createParent() => new Home();

Parent pages declare child URL patterns in getChildUrlPatterns:

protected override IEnumerable<UrlPattern> getChildUrlPatterns() =>
	RequestDispatchingStatics.GetFrameworkUrlPatterns( WebApplicationNames.Website )
		.Append( ServiceOrder.UrlPatterns.ServiceOrderIdPositiveInt( "create" ) );

This creates child URLs like /123 for each existing ID and /create for creating new records.

Entity setups

Entity setups group related pages under a shared parent with navigation tabs:

// EwlPage
// Parameter: int organizationId

partial class EntitySetup {
	protected override ResourceParent createParent() => new Home();

	protected override IEnumerable<ResourceGroup> createListedResources() =>
		new ResourceGroup( new Details( this ), new Rooms( this ), new Users( this ) ).ToCollection();
}

Child pages take the entity setup as a constructor parameter and use it as their parent.

Page content

UiPageContent provides the standard EWL UI chrome (sidebar, content area). Use BasicPageContent for pages without the EWL UI shell. The Add method is chainable:

protected override PageContent getContent() =>
	new UiPageContent()
		.Add( formItemList )
		.Add( table );

Securing pages

Override userCanAccess to restrict access:

protected override bool userCanAccess => SystemUser.Current is not null;

Authorization is hierarchical: child pages inherit the parent's restrictions and can only add additional ones. A child's userCanAccess never loosens the parent's. To access a child, the user must pass parentConditions && childConditions.

When linking to a page, always check UserCanAccess to avoid linking to pages the user cannot reach:

var page = new ServiceOrder( id );
if( page.UserCanAccess )
	// create hyperlink

The framework throws an exception if you create a link to an unauthorized page, to prevent users from ever seeing "access denied" errors.

Request dispatching

Each web application must have a RequestDispatching provider:

partial class RequestDispatching {
	protected override IEnumerable<BaseUrlPattern> GetBaseUrlPatterns() =>
		Home.UrlPatterns.BaseUrlPattern().ToCollection();

	public override UrlHandler GetFrameworkUrlParent() => new Home();
}