ArcGIS REST Api Blob Format

Question

Using the arcgis REST api (http://resources.arcgis.com/en/help/rest/apiref/) using the addFeatures link http://example.com//arcgis/rest/services/name/name/FeatureServer/0/addFeatures how do you add a blob. We've tried the following,

[
{
   "geometry" : {"x" : -118.15, "y" : 33.80},          "attributes" : {
     "name" : "Joe Smith",
     "title" : "Test",
     "descr": "324DFIOWNF83294"
   }
 }
]

does not work (error being Unable to complete operation, "Setting of value for descr failed.") however

[
{
   "geometry" : {"x" : -118.15, "y" : 33.80},          "attributes" : {
     "name" : "Joe Smith",
     "title" : "Test",
     "descr": null
   }
 }
]

edit Base64:

I also tried the following base64 version as Vince suggested

VGhpcyBpcyB0ZXh0IGVuY29kZWQgaW4gYmFzZTY0Lg==

being

This is text encoded in base64.

with the following,

[
{
   "geometry" : {"x" : -118.15, "y" : 33.80},          "attributes" : {
     "name" : "Joe Smith",
     "title" : "Test",
     "descr": "VGhpcyBpcyB0ZXh0IGVuY29kZWQgaW4gYmFzZTY0Lg=="
   }
 }
]

doesn't work.

What encoding does ArcGIS's REST service expect the blob to be in.

The field types are

name - esriFieldTypeString

title - esriFieldTypeString

descr - esriFieldTypeBlob

Specifically descr is,

descr ( type: esriFieldTypeBlob , alias: desc , editable: true , nullable: true )

ArcGIS Server version is 10.3.1

Answer 1

The ArcGIS Rest API does not support BLOBs for the JSON feature object. From the documentation:

The values are the field values, and they can be any of the standard JSON types: string, number, and boolean. ArcGIS REST API - Feature Object

Is there a reason you can't use Attachments in your project?

Answer 2

What we ended up doing is modifying the text length to 1500 instead of 255, this was done through the server database I believe. It was confirmed that for a long time there was a text limit of 255 and I swore I read that somewhere (however can't seem to find it).

I was unable to get the BLOB format working at all, neither through REST API or Javascript. My recommendation is to just increase the text length and use a esriFieldTypeString field. The other option is to use attachments which works for somethings as long as you don't have to search for it.

Summary: Extend the esriFieldTypeString field from a default of 255 to whatever you need. It seems in the past there was a limit of 255 but that is no longer the case it's just the default.