Container Data

Container fields in FileMaker store files (images, PDFs, etc.). FMData handles downloading and uploading container data separately from regular field data.

Model Setup

Add a byte[] property with [ContainerDataFor] referencing the container field’s C# property name:

[DataContract(Name = "Documents")]
public class Document
{
    [DataMember]
    public string Title { get; set; }

    [DataMember]
    public string Attachment { get; set; }  // container field

    [ContainerDataFor("Attachment")]  // references the C# property name
    public byte[] AttachmentData { get; set; }
}

Downloading Container Data

After finding records, use ProcessContainers to download all container data for a collection:

var results = await client.FindAsync(new Document { Title = "Report" });
await client.ProcessContainers(results);
// each result's AttachmentData now contains the file bytes

For a single record:

await client.ProcessContainer(singleDocument);

Auto-load on Find

Set LoadContainerData on a find request to automatically download container data with the results:

var req = client.GenerateFindRequest<Document>();
req.Layout = "Documents";
req.AddQuery(new Document { Title = "Report" }, omit: false);
req.LoadContainerData = true;

var results = await client.SendAsync(req);
// container data is already loaded

Uploading Container Data

Use UpdateContainerAsync to upload data to a container field:

var fileBytes = File.ReadAllBytes("report.pdf");

await client.UpdateContainerAsync(
    "Documents",         // layout
    recordId,            // FileMaker record ID
    "Attachment",        // container field name
    "report.pdf",        // file name
    fileBytes);          // file content

For repeating container fields, specify the repetition number:

await client.UpdateContainerAsync(
    "Documents", recordId, "Attachment", "report.pdf",
    repetition: 2, content: fileBytes);

Note: Creating a record with container data requires two calls — one to create the record, then a second to upload the container data.