Extract ArcGIS Feature Service Attachments into Field URL's

extractAttachmentURLs.py

#Author: Joshua Tanner
#Data: 7/7/2017
#Summary: Extract ArcGIS Feature Service Attachments into Field URL's

import copy, json, sys
from arcgis.gis import GIS

photo_field_name = 'attachment_url'
USERNAME = ''
PASSWORD = ''
ITEMID = '4e4e9be76fae4457b9ef5b11356164c8'

ago_gis = GIS('https://www.arcgis.com/', USERNAME, PASSWORD)
item = ago_gis.content.get(ITEMID)
lyr = item.layers[0]
data = lyr.query(where='1=1',out_fields='*')
maxAttachments = 0
fieldNames = []


def generateUrls(attachments, objectid):
    urls = []
    for item in attachments:
        urls.append("{}/{}/attachments/{}".format(lyr.url,objectid,item["id"]))
    return urls

def getAttachments(f):
    objectid = f.attributes['OBJECTID']
    attachments = lyr.attachments.get_list(objectid)
    return attachments

def generateAttachmentFieldNames():
    fieldNames = []
    for i in range(maxAttachments):
        fieldNames.append(photo_field_name + "_{}".format(i+1))
    return fieldNames

def removeDups(original, matches):
    notDups = []
    for f in original:
        if f not in matches:
            notDups.append(f)
    return notDups

def generateNewFieldDefs(fields):
    defs = []
    for f in fields:
        d = { "name": f,
              "editable": True,
              "alias": f,
              "type": "esriFieldTypeString",
              "length": 256,
              "nullable": True}
        defs.append(d)
    return defs
    
def createDefinition():
    fields = copy.deepcopy(lyr.manager.properties.fields)
    #make valid python dicts
    for i, f in enumerate(fields):
        f = '''{}'''.format(f)
        f = json.loads(f)
        fields[i] = f
    matches = [f['name'] for f in fields if f['name'] in fieldNames]
    newFields = removeDups(fieldNames, matches)
    newFieldDefs = generateNewFieldDefs(newFields)
    return newFieldDefs

def updateUrls(feature, urls):
    for i, url in enumerate(urls):
        feature.attributes[fieldNames[i]] = url

    status = lyr.edit_features(updates=[feature])
    print(status)

def getURLs():
    for f in data.features:
       urls = generateUrls(getAttachments(f), f.attributes['OBJECTID'])
       updateUrls(f, urls)
    
# Find max attachements
for f in data.features:
    l = len(getAttachments(f))
    if l > maxAttachments:
        maxAttachments = l
        
if(maxAttachments > 0):
    fieldNames = generateAttachmentFieldNames()
else:
    print('No Attachments in Feature Layer')
    sys.exit()

# Update lyr definition
fieldDefs = createDefinition()
status = {'success': False}
if(len(fieldDefs) > 0):
    print('Adding new attachment URL fields')
    status = lyr.manager.add_to_definition({"fields": fieldDefs})
    if(status['success']):
        getURLs()
else:
    #fields already there, try and update
    print('Fields already exist.  Updating.')
    getURLs()