global razor helper umb 8

Go to solution

Press Ctrl / CMD + C to copy this to your clipboard.

Copied to clipboard

Flag this post as spam?

This post will be reported to the moderators as potential spam to be looked at

Peter Cort Larsen 421 posts 1038 karma points

Nov 14, 2020 @ 11:11

Hi,

I have made a cshtml file in App_Code with global helper methods.

The problem is that i get an exception after build.

Compilation Error
Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.

Compiler Error Message: CS0534: 'helper' does not implement inherited abstract member 'WebPageExecutingBase.Execute()'

Source Error:

Line 50:     public class helper : UmbracoViewPage {

My code look like this

@using System.Text.RegularExpressions
@using Umbraco.Core.Models.PublishedContent;
@inherits UmbracoViewPage

@helper RenderImage(dynamic i)
{
    var picture = "";
    if (i.HasValue("image"))
    {
        picture = i.Value<IPublishedContent>("image").Url();
        <img src="@picture" class="img-resp" />
    }
}

Can anyone help?

Copy Link

Marc Goodson 2157 posts 14411 karma points MVP 9x c-trib

Nov 14, 2020 @ 21:34
0
Hi Peter

I'm not sure you need to inherit UmbracoViewPage at the top?
```
@inherits UmbracoViewPage
```
essentially you are saying that your @helper class inherits from UmbracoViewPage and this requires you to implement WebPageExecutingBase.Execute()

Which you 'could' do, but I think if you remove the @inherits statement then you won't need to and your helper will still work...

regards

Marc
Copy Link
Peter Cort Larsen 421 posts 1038 karma points

Nov 15, 2020 @ 12:38
0
Hi,

Thanks that helped.

I have another problem after this.

In the global helper, how do i convert the dynamic object thats passed into the method into the correct type?

I tried something like this, but thats not correct
```
@helper RenderImage(object i)
{

    var type = i.GetType();

    var sc = (type)i;


        if (!string.IsNullOrEmpty(sc.Image.ToString()))
        {
            IPublishedContent picture = sc.Image;
            <img src="@picture.Url" class="img-resp" />
        }
}
```
Copy Link
Søren Gregersen 441 posts 1884 karma points MVP 2x c-trib

Nov 15, 2020 @ 21:35
0
Hi,

The line var type = i.GetType(); gets information about a type, but not a type. In c# types are static, which means you need have it available at compile time.

Your RenderImage could be rewritten as:
```
@helper RenderImage(IPulishedContent c, string imageAlias = "Image")
{
    if(c==null) return;
    var image = c.Value<IPublishedContent>(imageAlias);
    if(image==null) return;

     <img src="@picture.Url" class="img-resp" />
}
```
Another rewrite could be:
```
@helper RenderImage(IContentWithImage c)
{
    if(c==null || c.Image == null) return;

     <img src="@c.Image.Url" class="img-resp" />
}
```
IContentWithImage would be a composition "Content With Image" that defines the Image-property
Copy Link
Peter Cort Larsen 421 posts 1038 karma points

Nov 15, 2020 @ 12:39

0

I know this is a very simple example, i have other more complex stuff i would like to have in a global helper file.

Copy Link
Peter Cort Larsen 421 posts 1038 karma points

Nov 16, 2020 @ 08:16

0

Hi ,

Thanks,

The problem is that i dont know the model beforehand, but all the models that use the helper has the same property.

Copy Link

Peter Cort Larsen 421 posts 1038 karma points

Nov 16, 2020 @ 08:19

The calling razor looks like this:

@using MYMODELNAMESPACE.Models.ModelsBuilder;
@using Perplex.ContentBlocks.Rendering;

@model IContentBlockViewModel<TwoColumnImageVideoElement>
@{
    var imageSlider = Model.Content.FirstColumn;
}
@if (imageSlider.Any())
{
    foreach (var i in imageSlider)
    {
        var images = i.ImageItems;
        foreach (var img in images)
        {
            if (img.HasValue("image"))
            {
                var RenderImage = helper.RenderImage(img);
                @RenderImage
            }

        }
    }
}

Copy Link

Marc Goodson 2157 posts 14411 karma points MVP 9x c-trib

Nov 16, 2020 @ 08:26
100
Hi Peter

What is the type of imageSlider and i.ImageItems?

IEnumerable<IPublishedContent> or IEnumerable<IPublishedElement> ??

It's hard to tell, but it's likely your img, implements IPublishedContent so you could probably use that as your type in your razor helper.
```
@helper RenderImage(IPublishedContent i)
```
??

If your razor helper, is rendering HTML would it be better to have another PartialView for rendering images, that you called like Html.Partial("RenderImagePartial", model);

rather than a razor helper?

or perhaps an extension method on HtmlHelper, so you could call it in your views like @Html.RenderImageHelper(model): https://docs.microsoft.com/en-us/aspnet/mvc/overview/older-versions-1/views/creating-custom-html-helpers-cs

regards

Marc
Copy Link

Peter Cort Larsen 421 posts 1038 karma points

Nov 16, 2020 @ 10:25

Hi,

yes, this is the way.

 public static string RenderImage(IPublishedContent Image)
    {
        if (Image != null)
        {
            return String.Format("<img src='{0}' class='img-resp'/>", Image.Url());
        }
        return string.Empty;
    }

Then i can call it like this:

   @Html.Raw(UmbracoHelperExtensions.RenderImage(i.Image))

Thanks

Copy Link

is working on a reply...

Please Sign in or register to post replies