I have three components that I want to pass values and eventcallbacks through: First I have MainLayout that is a LayoutComponent
@inherits LayoutComponentBase
<div class="cms-container">
<div class="header">
<div class="header-logo">
CMS
</div>
<div class="header-settings">
<div class="header-settings__alert">
<i class="fa fa-bell"></i>
<div class="header-settings__alert--no">
<div class="header-settings__alert--no__text">
2
</div>
</div>
<ul class="cms-dropdown">
<li class="cms-dropdown__alert">
<span class="cms-dropdown__alert--status"><i class="fa fa-info-circle font-danger"></i></span>
<span class="cms-dropdown__alert--left">Följ upp händelse</span><span class="cms-dropdown__alert--right">1 dgr</span>
</li>
<li class="cms-dropdown__alert">
<span class="cms-dropdown__alert--status"><i class="fa fa-info-circle font-success"></i></span>
<span class="cms-dropdown__alert--left">Tidrapport behöver lämnas in</span><span class="cms-dropdown__alert--right">3 dgr</span>
</li>
</ul>
</div>
<div class="header-settings__org">
<span class="header-settings__org--text">
Kanal10.se
</span>
<ul class="cms-dropdown">
<li class="cms-dropdown__normal">
<div class="cms-dropdown__normal--icon">
<i class="fa fa-tasks"></i>
</div>
<div class="cms-dropdown__normal--text">Uppgifter</div>
</li>
<li class="cms-dropdown__normal">
<div class="cms-dropdown__normal--icon">
<i class="fa fa-users"></i>
</div>
<div class="cms-dropdown__normal--text">Användare</div>
</li>
</ul>
</div>
<div class="header-settings__account">
<i class="fa fa-user"></i>
<ul class="cms-dropdown">
<li class="cms-dropdown__normal">
<div class="cms-dropdown__normal--icon">
<i class="fa fa-user"></i>
</div>
<div class="cms-dropdown__normal--text">Min profil</div>
</li>
<li class="cms-dropdown__normal">
<div class="cms-dropdown__normal--icon">
<i class="fa fa-money-check"></i>
</div>
<div class="cms-dropdown__normal--text">Lönebesked</div>
</li>
</ul>
</div>
<div class="header-settings__system">
<div class="header-settings__system--icon">
<i class="fa fa-cog"></i>
</div>
<ul class="cms-dropdown">
<li class="cms-dropdown__normal">
<div class="cms-dropdown__normal--icon">
<i class="fa fa-bars"></i>
</div>
<div class="cms-dropdown__normal--text">Menyer</div>
</li>
<li class="cms-dropdown__normal">
<div class="cms-dropdown__normal--icon">
<i class="fa fa-users"></i>
</div>
<div class="cms-dropdown__normal--text">Användare</div>
</li>
<li class="cms-dropdown__normal">
<div class="cms-dropdown__normal--icon">
<i class="fa fa-shield-alt"></i>
</div>
<div class="cms-dropdown__normal--text">Behörighetsgrupper</div>
</li>
</ul>
</div>
</div>
</div>
<div class="LeftNav">
<NavMenu />
</div>
<TelerikRootComponent>
<div class="cms-content">
@Body
</div>
</TelerikRootComponent>
<div class="footer">
<div class="footer-body">
<div class="footer-body__left">
</div>
<div class="footer-body__right">
<CascadingValue Value="visible">
<SaveAndCancelBtns OnBtnAction="?" />
</CascadingValue>
</div>
</div>
</div>
</div>
<BlazoredToasts Position="Blazored.Toast.Configuration.ToastPosition.TopCenter"
Timeout="3"
IconType="IconType.FontAwesome"
SuccessClass="success-toast-override"
SuccessIcon="fa fa-thumbs-up" />
@code {
private bool visible = false;
}
Then I have a child component called Buttons.razor
@if (visible == true)
{
<div class="footer-body__right--item">
<button class="btn btn-primary" @onclick="Save" type="submit">Save</button>
</div>
<div class="footer-body__right--item">
<button class="btn btn-cancel" @onclick="Cancel">Cancel</button>
</div>
}
[Parameter] public EventCallback<string> OnBtnAction { get; set; }
[Parameter] public bool visible { get; set; }
private void Save()
{
OnBtnAction.InvokeAsync("Save");
}
private void Cancel()
{
OnBtnAction.InvokeAsync("Cancel");
}
}
And then I have the component razor page called pageDetail.razor
@page "/pages/detail/{Id}"
@page "/pages/detail"
<div class="wrapper">
<div class="cms-content__title">
<div class="cms-content__title-left">
Page Detail
</div>
</div>
<div class="cms-content__page">
<div class="cms-content__page-all">
@if (cmsPage == null)
{
<ErrorMessage Message="Loading..." />
}
else
{
<div class="col-6">
<EditForm Model="cmsPage" OnValidSubmit="SavePage">
<DataAnnotationsValidator />
<ValidationSummary />
<div class="form-group">
<label for="PageTitle">Page Title</label>
<InputText @bind-Value="@cmsPage.PageTitle" class="form-control" id="PageTitle"></InputText>
</div>
<div class="form-group">
<label for="PageTitle">Page Descr</label>
<InputTextArea @bind-Value="@cmsPage.PageDescr" class="form-control" id="PageTitle"></InputTextArea>
</div>
<div class="form-group">
<label for="PageTitle">Page Url</label>
<InputText @bind-Value="@cmsPage.UrlName" class="form-control" id="PageTitle"></InputText>
</div>
<div class="form-group">
<label for="PageTitle">Page Type</label><br />
<TelerikComboBox Data="@cmsPageTypes" TextField="PageType" Width="100%" ValueField="PageTypeId" @bind-Value="selectedValue">
</TelerikComboBox>
<ValidationMessage For="@(() => cmsPage.PageTypeId)" />
</div>
<div class="form-group">
<label for="PageTitle">Parent Page</label><br />
<TelerikTreeView Data="@cmsPages" OnItemClick="@OnItemClickHandler">
<TreeViewBindings>
<TreeViewBinding IdField="PageId" TextField="PageTitle" ParentIdField="ParentId" HasChildrenField="false"></TreeViewBinding>
</TreeViewBindings>
</TelerikTreeView>
</div>
<button class="btn btn-primary" type="submit">Save</button>
<button class="btn btn-danger" @onclick="DeletePage">Delete</button>
<button class="btn btn-info" @onclick="BackToList">Back To List</button>
</EditForm>
</div>
}
</div>
</div>
</div>
@code{
"not sure how to implement the event button action"
}
What I want is to:
The thing is how to handle the component that is a LayoutComponent. Not sure how it fits in the logic.
As you can see I have started implementing it but am not sure of how to connect the different parts.
Grateful for help! Peter
I'd recommend looking at this article: https://chrissainty.com/3-ways-to-communicate-between-components-in-blazor/ but you're part of the way there by using the <CascadingParameter> in your layout.
In your case I'm not keen on using a boolean visible as a cascading parameter, it's a bit simplistic. The cascading value is also in the wrong place for this as it needs to wrap both the @Body render and the buttons.
I'd create a state class and cascade that class to any child that wants to use it, by wrapping the @Body and the <SaveAndCancelBtns ..>
<CascadingValue Value="buttonState" >
<TelerikRootComponent>
<div class="cms-content">
@Body
</div>
</TelerikRootComponent>
<div class="footer">
<div class="footer-body">
<div class="footer-body__left">
</div>
<div class="footer-body__right">
<SaveAndCancelBtns />
</div>
</div>
</div>
</CascadingValue>
You also need to add a value in the layout code:
ButtonStates buttonState = new ButtonStates();
The ButtonStates class should provide the values and events you need, e.g.
public class ButtonStates
{
public bool Visible { get; private set; }
// etc
}
Rather than put all the code here I've created a simple sample repo on github for you: https://github.com/conficient/CascadingStateExample
Note that I've just used a simple state container and event to pass events from it. EventCallback<T> is specifically used to wire up events between Razor components.