I'm using ndb.Model. The Search API has the following field classes:

    TextField : plain textHtmlField : HTML formatted textAtomField : a string which is treated as a single tokenNumberField : a numeric value (either float or integer)DateField : a date with no time componentGeoField : a locale based on latitude and longitude

Suppose I have a 'tags' field which is a list field:

    tags = ndb.StringProperty(repeated=True)

How am I supposed to treat this field with search.Document?

Right now I'm turning tags list into a string:

    t = '|'.join(tags)

And then:

    search.TextField(name=cls.TAGS, value=t)

Any suggestions?

You should add as many fields as 'tags' you have, all with the same field_name:

doc = search.Document(fields=[search.TextField(name='tag', value=t) for t in tags
])

As in the docs:

A field can contain only one value, which must match the field's type. Field names do not have to be unique. A document can have multiple fields with the same name and same type, which is a way to represent a field with multiple values. (However, date and number fields with the same name can't be repeated.) A document can also contain multiple fields with the same name and different field types.