Media processing script

This is an example of a Media processing web script, which is executed every time an asset is processed by the respective worker (for example, when a new asset is uploaded or when an asset rendition is refreshed). It extracts the metadata properties from the context and adds them to the asset.

Script

using System.Linq;

var masterFileRelation = await Context.File.GetRelationAsync<IChildToManyParentsRelation>("MasterFile");

if (!masterFileRelation.Parents.Any() || !masterFileRelation.Parents.Contains(Context.Asset.Id.Value))
{
  return;
}

string ToCsvValue(object source)
{
  var str = source.ToString();
  if (str.Contains(","))
  {
    return "\"" + str + "\"";
  }
  return str;
}

var headers = string.Join(", ", Context.MetadataProperties.Keys.Select(ToCsvValue));
var values = string.Join(", ", Context.MetadataProperties.Values.Select(ToCsvValue));

var metadataProp = await Context.Asset.GetPropertyAsync<ICultureInsensitiveProperty>("Metadata");
metadataProp.SetValue(headers + "\n" + values);

await MClient.Entities.SaveAsync(Context.Asset);

Script explanation

This section steps through the script in execution order, explaining each part. The numbered items describe the sequence, not instructions to perform.

Include the libraries to be used in the script.
using System.Linq;

Get the MasterFile relation of the asset.

var masterFileRelation = await Context.File.GetRelationAsync<IChildToManyParentsRelation>("MasterFile");

Check if the current file is the master file. Only this metadata is to be copied if this is the case.

if (!masterFileRelation.Parents.Any() || !masterFileRelation.Parents.Contains(Context.Asset.Id.Value))
{
  return;
}

Create a method that checks whether the property already has commas and escapes them with quotation marks.

string ToCsvValue(object source)
{
  var str = source.ToString();
  if (str.Contains(","))
  {
    return "\"" + str + "\"";
  }
  return str;
}

Convert the metadata headers to csv.

var headers = string.Join(", ", Context.MetadataProperties.Keys.Select(ToCsvValue));

Convert the metadata values to csv.

var values = string.Join(", ", Context.MetadataProperties.Values.Select(ToCsvValue));

Get the metadata property field of the asset.

var metadataProp = await Context.Asset.GetPropertyAsync<ICultureInsensitiveProperty>("Metadata");

Store the metadata on the asset.
metadataProp.SetValue(headers + "\n" + values);
Save the asset.
await MClient.Entities.SaveAsync(Context.Asset);

Setup

Create a string property called Metadata on the M.Asset definition, setting the content type to Multiple lines.
Create, publish, and enable a metadata processing script.

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