See me at Esri's User Conference 2015

I'm going to be at UC 2015 presenting about ArcREST in the demo theater.

12:30 PM - 01:15 PM : Using the ArcREST Python Package on Tuesday 7/21/2015.

Hope to see you all there!

ArcREST - New Geoprocessing Model

Today ArcREST has a geoprocessing (GP) update.  The changes are minor, but the results are big.  The GP objects has been streamline so all the properties are the same.

Example of GPObject in Action:

import arcrest
# convert a feature class to a GPFeatureRecordSet
gpfrs = arcrest.ags.GPFeatureRecordSetLayer.fromFeatureClass(r"c:\temp\grid.gdb\sample", paramName="parameterName on GP tool")

The above code shows converting a feature class into a GPFeatureRecordSet object that can be given to a task that asks for that type of parameter.

Working with GP services is easy as well.

Example:

import arcrest
if __name__ == "__main__":
    sh = arcrest.AGSTokenSecurityHandler(username="user",
                                         password="password",
                                         token_url="http://site:6080/arcgis/admin/generateToken"
                                         )
    url = "http://site:6080/arcgis/rest/services/gp/scriptmv/GPServer"
    gp = arcrest.ags.GPService(url=url,
                               securityHandler=sh)
    for task in gp.tasks:
        if task.name.lower() == "":
            # submit the job
            job = task.submitJob(inputs=None)
            # wait till the job finishes
            while job.jobStatus != "esriJobSucceeded": pass
            # get the job results
            results = job.results # do something here.

Here we accessed a GP service and found a tool we wanted to run.  Since we are running the process async, submitJob() was used.  The function has additional options, like submitting the result via POST verse GET, etc...

Enjoy

ArcREST Publishing Part 1 - CSV Files

One of the main purposes of ArcGIS.com is that is allows you to share information.  Sometime you want to quickly stage content, or you want to mirror your site in another location.

So in this post, I will show you how to do some publishing.  Publishers can create feature services as well as tiled map services.

Feature services can be created using input files of type csv, shapefile, serviceDefinition, featureCollection, and fileGeodatabase.

The AGOL/Portal REST has some great bullet points to remember when publishing items:

• CSV files that contain location fields, (ie.address fields or X, Y fields) are spatially enabled during the process of publishing.
• Shapefiles and file geodatabases should be packaged as *.zip files.
• Tiled map services can be created from service definition (*.sd) files, tile packages, and existing feature services.
• Service definitions are authored in ArcGIS for Desktop and contain both the cartographic definition for a map as well as its packaged data together with the definition of the geo-service to be created.
• Use the Analyze operation to generate the default publishing parameters for CSVs.

Now that we have what we can publish, it is time to start coding!

This post will cover publishing CSV files.

CSV files require a bit more steps then the other publishing work flows because not only do you have to upload your data, you should analyze it in order to get a correct set of default publishing properties.  Luckily, ArcREST can ease the pain.

import arcrest

if __name__ == "__main__":
    username = "some account"
    password = "some password"
    csv_file = r"C:\Users\andr5624\Desktop\book1.csv"

    sh = arcrest.AGOLTokenSecurityHandler(username, password)
    admin = arcrest.manageorg.Administration(securityHandler=sh)
    content = admin.content
    usercontent = content.usercontent(username=username)
    ip = arcrest.manageorg.ItemParameter()
    ip.title = "Sample CSV"
    ip.type = "CSV"
    ip.tags = "tag1,tag3"
    res = usercontent.addItem(itemParameters=ip,
                              filePath=csv_file)
    itemId = res['id']

    #  Now you need to analyze the item to publish it
    #
    featureContent = content.featureContent
    analyzeParams = arcrest.manageorg.AnalyzeParameters()
    analyzeResult = featureContent.analyze(itemId=itemId, analyzeParameters=analyzeParams)
    #  Published based off the analyze function
    #
    if 'publishParameters' in analyzeResult:
        pp = analyzeResult['publishParameters']
        publishParams = arcrest.manageorg.PublishCSVParameters(name=pp['name'],
                                               locationType=pp['locationType'],
                                               layerInfo=pp['layerInfo'],
                                               latitudeFieldName=pp["latitudeFieldName"],
                                               longitudeFieldName=pp['longitudeFieldName'])
        print usercontent.publishItem(fileType="csv",
                                      publishParameters=publishParams,
                                      itemId=itemId)

Let's discuss the above code. Here we access AGOL and add an item for our user.  Once uploaded, the code, using the item id, analyzes the CSV to get a set of default publishing parameters.  These parameters are used to populate the PublishCSVParameters class in order to publish the CSV file correctly.

Pretty cool.  ArcREST masks a complex work flow into a couple of short lines of Python code.

ArcREST Basics - Creating a Group

Managing your portal or AGOL site can be a tough task, and ArcREST is here to help.  Often within your organization, individuals need new groups or maybe you need to create a set of default groups.  ArcREST allows individuals to create a list of group then put users into that group easily.  

The Pointy Hair Boss (http://www.andrewlipson.com/)

So here is the situation.  You boss wants you to create a group called 'Publishing Review'.  This group will contain all your users must be in this group.  The point of this group is that non-administrator accounts cannot publish to the public, and any data within this group will be reviewed by administrators on a given cycle and published if the information meets the organizations standards.

Let's begin!

import arcrest
#--------------------------------------------------------------------------
def getAllUsers(portalId, admin):
    """
       returns all the users for a given AGOL

       Inputs:
          portalId - unique id of the portal
          admin - manageorg.Administration object
       Output:
          returns a list of the users
    """
    start = 1
    num = 100
    portals = admin.portals(portalId=portalId)
    count = 0
    nextStart = 0
    results = []
    while nextStart > -1:
        users = portals.users(start=start + (num * count),
                              num=num)
        results = results + users['users']
        count += 1
        nextStart = users['nextStart']
        del users
    return results
#--------------------------------------------------------------------------
if __name__ == "__main__":
    #   Connect to the site
    #
    sh = arcrest.AGOLTokenSecurityHandler(username, password)
    admin = arcrest.manageorg.Administration(securityHandler=sh,
                                             initialize=True)
    community = admin.community
    portals = admin.portals()
    groups = community.groups
    portalId = portals.portalId
    #   Create Group
    #   Basic group inputs
    access = "org"
    groupTitle = "Pre Publishing Group"
    groupTags = "Publishing;Service Management"
    description = "This group allows users to request publishing services to public."
    # search to see if the group exists. If not, create the group, else use the ID 
    searchResult = community.getGroupIDs(groupNames=groupTitle)
    if len(searchResult) == 0:
        groupId = community.createGroup(title=groupTitle,
                                tags=groupTags,
                                description=description,
                                snippet="",
                                phone="",
                                access=access,
                                sortField="title",
                                sortOrder="asc",
                                isViewOnly=False,
                                isInvitationOnly=False,
                                thumbnail=None)['group']['id']
    else:
        groupId = searchResult[0]
    # Get all the site's users and add them to the group
    users = [user['username'] for user in getAllUsers(portalId=portalId, admin=admin)]
    if len(users) > 0:
        groups.addUsersToGroups(users=",".join(users), groupID=groupId)

So let's review the code.  First we connect to our site.  Next we grab all the objects we will need to work with in order to make the magic happen.  Since the topic is groups, there is a need to work with the community functions as well as some portal functions.  This will give us all the access we need.  After we do all of that, we need to know the group ID, this is found by either creating the group or if it exists, getting the site to return the information to us.  Using the community object, call the getGroupIDs() returns the IDs for a group or groups as a list.  If the list if < 1 then create the group using the createGroup() else use the search result Id to add the users.

To get all the users, I created a function that will go and grab all the users from the portal object.  All you need to pass is the portalId and the administration objects and I detailed list of users will be returned.  Since in this sample we only need username, we can just parse out what we need and move on as shown above.

Hope this have been a helpful post, keep on rocking, and post your questions/comments/enhancements on the ArcREST page: http://www.github.com/Esri/ArcREST

ArcREST Basics - ArcGIS Online and Query()

In this weeks ArcREST basics series, I am going to go into the how to connect to your organization on ArcGIS Online (AGOL) using Python, and perform some basic queries using the manageorg sub-package in ArcREST.

First we start by building off the previous lesson and create a security handler object for AGOL.  If you missed a deeper discussion on how to handle security, please see this post.

One of the most common tasks to perform when working with your site, is to query it to see what content you have.  There are two ways to query a site:

1. With Credentials - this means a token will be appended on the end of the query search, and users can find both public and non-public items if your users has the proper permissions to do so.
2. Without Credentials - this means only find public items shared with everyone.

In the example below, a query is being performed with credentials being given.  This means case #1 will be applied.

from arcrest.security import AGOLTokenSecurityHandler
from arcrest.manageorg import Administration
if __name__ == "__main__":
    username = "username"
    password = "password"
    proxy_port = None
    proxy_url = None    
    securityHandler = AGOLTokenSecurityHandler(username, password,
                                               proxy_url=proxy_url,
                                               proxy_port=proxy_port)
    siteObject = Administration(securityHandler=securityHandler,
                                proxy_url=proxy_url,
                                proxy_port=proxy_port)
    results = siteObject.query(q="< some query string >")

This returns a Python dictionary object as shown below:

{
   "query" : "type:feature class",
   "total" : 12345,
   "start" : 1,
   "num" : 10,
   "nextStart" : 11,
   "results" : [ ...list of items... ]
}

Let us examine the results object.  It's a dictionary with many valuable key/value pairs.  Since this query was performed using the default values, this means that the query will begin with the first item and go to the 10th item (num).  The key nextStart tells you where the start value needs to be if you want to page each result.  So the next time you pass the query in order to get all the results you need to set the start = 11.  Manually this seems quite daunting task, but luckily for us, we have looks.  There are many way to create loops to perform this task, but in this example, a while loop will be used to walk the results and put them in a single list object.

def findContentByDate(admin, q):
    """
       finds items based on a query (q)

       Inputs:
    
          admin - manageorg.Administration object
          q - query string
    """
    start = 1
    count  = 0
    nextStart = 0
    num = 100
    results = []
    while nextStart != -1:
        query = admin.query(q=q,
                        sortOrder="desc",
                        sortField="modified",
                        t=None,
                        start=start + (count * num),
                        num=100)
        results = results + query['results']
        nextStart = query['nextStart']
        count += 1
    return results

Now we have all the items based on a query in a single Python list. This is very helpful in cataloging a site/org or even good for finding publicly shared items.

AGOL has it's own query language much like the google or other search engines.  This documentation can be found here (http://doc.arcgis.com/en/arcgis-online/reference/search.htm).  It is a must read for anyone who wants to query AGOL or Portal effectively.

Though the samples shown are created to work with Portal, then same example can be used to query a Portal site.

If you want to learn more, please visit the ArcREST Github Page.  Help us make it better and post comments, suggestions and improvements in the Issues section.  Or better yet, fork the repo and submit a pull request.

Happy Coding and Enjoy!

ArcREST Basics - Authentication

When starting working with any new package, there is always a learning curve, and I am trying to make ArcREST easy and fun to use.   So here is my first of many ArcREST posts on how to use this package to meet your Esri REST API use cases.

This post will focus on the most basic thing, authentication.  Authentication is the most basic idea to understand when working with ArcGIS Online, ArcGIS Server, or ArcGIS Portal.  It identifies who you are, and what you are allowed to do.  Not all operations require authentication, but it's good to understand the token based security model and how it applies to you ArcGIS stack.

A quick blurb from the ArcGIS help describes what token security does:

ArcGIS Server provides a proprietary token-based authentication mechanism where users can authenticate themselves by providing a token instead of a user name and password. An ArcGIS token is a string of encrypted information that contains the user's name, the token expiration time, and some proprietary information. To obtain a token, a user provides a valid user name and password. ArcGIS Server verifies the supplied credentials and issues a token. The user presents this token whenever accessing a secured resource.

Before ArcREST, I you probably had to write this function out a lot:

import urllib
import urllib2
import httplib
import time
import json
import contextlib

def submit_request(request):
    """ Returns the response from an HTTP request in json format."""
    with contextlib.closing(urllib2.urlopen(request)) as response:
        job_info = json.load(response)
        return job_info

def get_token(portal_url, username, password):
    """ Returns an authentication token for use in ArcGIS Online."""

    # Set the username and password parameters before
    #  getting the token. 
    #
    params = {"username": username,
              "password": password,
              "referer": "http://www.arcgis.com",
              "f": "json"}

    token_url = "{}/generateToken".format(portal_url)
    request = urllib2.Request(token_url, urllib.urlencode(params))
    token_response = submit_request(request)
    if "token" in token_response:
        print("Getting token...")
        token = token_response.get("token")
        return token
    else:
        # Request for token must be made through HTTPS.
        #
        if "error" in token_response:
            error_mess = token_response.get("error", {}).get("message")
            if "This request needs to be made over https." in error_mess:
                token_url = token_url.replace("http://", "https://")
                token = get_token(token_url, username, password)
                return token
            else:
                raise Exception("Portal error: {} ".format(error_mess))

It is lots of code just to gain access.  As a user/developer you have not even begun to work on your actual workflow of what you need.

So there has to be an easier way? 

Well there is!  ArcREST supports three main forms of token based security in the form of classes.

• PortalTokenSecurityHandler - this allows access to ArcGIS Portal Site
• AGOLTokenSecurityHandler - this generates a token for ArcGIS Online
• AGSTokenSecurityHandler - this generates a token for ArcGIS Server Sites

Why should I use this? 

1. allows for cleaner code
2. pass username/password once in your code
3. built in proxy support 
4. handles token expiration automatically

#3 is a biggie, at least in my eyes.  For long running tasks, there is a chance, depending on your expiration time, that your token might fail you because it is too old.  The SecurityHandler classes automatically handle the expiration for you, and regenerate new tokens as needed.

Examples of creating Securityhandler objects:

1. Creating an ArcGIS Server Security Handler

import arcrest
if __name__ == "__main__":
    token_url = "http://mysite.com:6080/arcgis/admin/generateToken"
    username = "username"
    password = "password"
    sh = arcrest.AGSTokenSecurityHandler(username=username,
                                         password=password,
                                         token_url=token_url)

2. Creating an ArcGIS Online Security Handler

import arcrest
if __name__ == "__main__":
    username = "< username >"
    pw = "< password >"
    proxy_url = None
    proxy_port = None
    sh = arcrest.AGOLTokenSecurityHandler(username, password=pw)

3. Creating an ArcGIS for Portal Security Handler

import arcrest
if __name__ == "__main__":
    username = "< username >"
    pw = "< password >"
    tokenUrl = "https://mysite.com/portal/sharing/rest/generateToken"
    org_url = "https://mysite.com/portal/sharing/rest"
    sh = arcrest.PortalTokenSecurityHandler(username=username, 
                                            password=pw, 
                                            org_url=org_url, 
                                            token_url=tokenUrl)

In each example, it shows how to generate the token handlers.  You then can pass the security handlers objects onto other functions like arcrest.manageorg.Administration(), which will allow administrators to perform operations to manage a portal or AGOL site.

Hope this helps!


Please download ArcREST here (http://www.github.com/Esri/ArcREST)
If you use ArcREST, help us out and post comments in the issues sections.  We are always trying to make it better.  If you think you can make it better, fork it and submit a pull request!

ArcREST Update - update your forks!

Today I pushed into the master git repository an update that allows users who use Requests to have ArcREST default to that.  If requests if not present, never fear, the library falls back to the standard urllib modules in the basic python install.

Enjoy!