Tridion DXA How to get Multimedia Component metadata

Question

I have seen few posts regarding the same topic. However, I couldn't resolve the issue what I have.

I have a content schema, which has "Multimedia Link" field. I have created the model as below for my content schema.

[SemanticEntity(Vocab = "http://www.sdl.com/web/schemas/core", EntityName = "TextImage", Prefix = "tim", Public = true)]
public class TextImage:EntityModel
{
    [SemanticProperty("tim:multimedia_link")]
    public Image Multimedia_Link { get; set; }
    [SemanticProperty("tim:title_text")]
    public String Title_Text{ get; set; }

}

Below is my Image Model class:

public class Image :MediaItem
{   
    public override string ToHtml(string widthFactor, double aspect = 0, string cssClass = null, int containerSize = 0)
    {
        throw new NotImplementedException();
    }
}

I have created my own multimedia schema with metadata fields. I have below questions. could you please help me with that?

1. How to create model for the metadata fields in my Image class? Say for Eg: I have meta fields like (alt_text, height, width)
2. How to set value for the metadata fields?

Thanks in advance. Jey

Answer 1

Model mapping for metadata felds works the same as for content fields; the model mapping considers both when resolving a semantic property name to a field.

The only special thing for Multimedia Components/Schemas is that they don't have a (content) Root Element Name, so the Title of the MM Schema is used as Semantic Entity name (instead of the Schema's Root Element Name as is done for regular Components/Schemas).

To be precise: the MM Schema's title, excluding any whitespace is used.

See, for example, https://github.com/sdl/dxa-modules/blob/master/webapp-net/MediaManager/Models/MediaManagerDistribution.cs