Breaking Change in ImageResizer EPiServer Plugin

Usually I don’t post small changes in separate blog post, but I think that it’s worth to mention breaking changes in latest ImageResizer (IR) plugin for EPiServer.

Before

If you are using Fluent API to resize the image, then you may face inconsistency in API. Passing in null or ContentReference.EmptyReference you will get an ArgumentNullException exception:

@Html.ResizeImage(null, 100, 100)

However, if passing in string.Empty for the another overload - you would get back empty string:

@Html.ResizeImage(string.Empty, 100, 100)

Why this is bad - you can read more here. Thx to Kaspars for the link. This is inconsistent API and should be fixed.

After

Now (in v6.0 and after) in any case when markup could potentially end up with empty src attribute - ResizeImage will throw an exception. Both invokes will blow up:

@Html.ResizeImage(null, 100, 100)
@Html.ResizeImage(string.Empty, 100, 100)

Render with Fallback

Now, to render image from the page property could be cumbersome. You also would need to check for existence of the content reference.

@{
    var imageUrl = Model.ImageLink.IsNullOrEmpty()
        ? new UrlBuilder(string.Empty)
        : Html.ResizeImage(Model.ImageLink, 1600, 670);
}

<div data-src="@imageUrl">

To make life easier, there is a new overload in the library:

<div data-src="@Html.ResizeImageWithFallback(Model.ImageLink, "", 1600, 670)">

Anyways, just be sure to pass in valid fallback image path if you still resizing for img element, otherwise - you still might destroy your site.

Happy resizing!

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