Every day before I even wake up, I have little "SAS robots" that do work for me. These are SAS batch jobs that gather data from external services and build data marts, generate reports, and send e-mail. One of those SAS jobs gathers Google Analytics data about our SAS blogs at blogs.sas.com.
With SAS 9.4 Maintenance 4, it's finally easy (well, relatively speaking) to connect to complicated APIs like those supported by Google, and to gather information with an unattended batch process. It's made possible by recent enhancements in PROC HTTP and the new JSON library engine in SAS. The PROC HTTP enhancements make it easier to negotiate multi-step authentication schemes like OAuth2. And of course, the JSON engine makes it easier to parse JSON results into SAS data sets. If you scour the Internet and SAS conference papers, you might find examples that use PROC GROOVY or other tricks to call outside of SAS to drive these OAuth2 APIs and parse JSON. The recent enhancements make such tricks unnecessary, and thus provide a cleaner approach with fewer moving parts.
Joseph Henry, a senior software developer at SAS (and primary developer for PROC HTTP), wrote a useful SAS Global Forum paper about PROC HTTP and OAuth2. Joseph definitely understands this better than I do, so I recommend that you read his paper first. Joseph's example uses Google Drive. Come back to this post when you want to see the instructions I've hacked together -- it's what I've got working for Google Analytics.
How to use the Google APIs
There are four main steps to use the Google APIs. Two of these steps need to be performed just once, and don't need to be automated. The other two steps are necessary each time you access a Google API from a program, and they can be scripted. Here are the steps:
- Grant permission and obtain an authorization token for your "app" (a SAS program, in our case). This must be performed in a browser while logged into your Google account.
- Obtain an access token and refresh token. You can accomplish this with a SAS program that you run just once. You then save the refresh token (in a safe place!) for subsequent runs.
- Convert your saved refresh token into an access token. Do this at the start of every SAS job that needs to get Google Analytics data.
- And finally, use the Google Analytics API to get actual data!
There is a lot to learn about how Google APIs work and how to provision your Google account with access to resources like Google Analytics. That's more than I can go into here, so I'm going to assume a few things and skip ahead. I'm going to assume that you already have an API project created, and that you have a "client ID" and "client secret". The Google API documentation is very good on this topic, and there are many Internet resources to help you learn this part of the process.
Also, some Google APIs are free to use, while others cost money. And some are rate-limited -- that is, you can call the APIs only so many times within a given period. Your specific limits might differ depending on the type of accounts you have with Google. If you have a corporate relationship with Google, you might have an admin who has to provision your specific Google account to get access to the APIs. I'm glossing over all of these nuances -- this post is simply about the code.
Step 1. Grant permission and retrieve auth code
Do this step only once per account, per API permission. You perform this step in the browser while logged into your Google account. Enter the following URL, substituting your client-id as indicated. The URL needs to be all on one line, but I've broken it up here for readability.
You will be prompted to allow the "app" access to your Google Analytics data (read only). This is similar to allowing another app to access your Facebook or Twitter profile -- you've probably seen similar prompts during your own Internet citizenship. Permissions are an important component of allowing apps to act on your behalf via REST APIs.
Then, you'll be redirected to a web page with an auth code that you should copy and save. We'll use it in the next step. Setting the redirect_uri properly is very important: redirect_uri=urn:ietf:wg:oauth:2.0:oob. Otherwise the API won't generate a code that you can use in a tool-based app like SAS.
Step 2. Exchange the auth code for an access token
Next, run this PROC HTTP step in SAS with the POST method to exchange that auth code from Step 1 for an access token. It will return a JSON response with a valid Bearer access token. That token expires in 3600 seconds (1 hour). It also returns a refresh_token, which you can exchange again for a new access token after the first one expires. The refresh_token never expires (though it can be revoked via the developer console or API). Thus, you usually need to perform this step just once, unless your token is revoked for some reason.
/* file to store your result */
filename token "c:\temp\token.json";
%let code_given =<code-returned-from-step-1> ;
/* put this all on one line! */
Note: the refresh_token and client-id/secret values should be protected! Anyone who has access to these can get to your Google API data as if they were you. Consider storing them in a file that only you have read access to, and programmatically pull them in when running your SAS program under your host account.
Step 3. Exchange the refresh_token for a valid access token
Typically, you'll include this step just once at the beginning of your SAS job. This takes your saved refresh_token value and asks Google to grant an access token for use in the rest of your program. The Google APIs run very fast -- you should not need to renew the token again within the same job.
/* STEP 3. Do this every time you want to use the GA API */
/* Turn in a refresh-token for a valid access-token */
/* Should be good for 60 minutes */
/* So typically run once at beginning of the job. */
filename rtoken temp;
/* Again, put this all on one line */
/* broken here for readability */
/* Read the access token out of the refresh response */
/* Relies on the JSON libname engine (9.4m4 or later) */
libname rtok json fileref=rtoken;
Step 4. Use the Google Analytics API to gather data
Finally, we're to the point where we can retrieve data from this service! And this is where those new features in PROC HTTP come into play. In SAS 9.4m3, Joseph added support for an inline HEADERS statement, which is perfect for injecting OAuth2 information like "Bearer" token into the HTTP header.
/* Headers statement makes this easy */
I've noticed that a lot of REST API docs use cUrl (command-line URL) as in their examples. In my experience, PROC HTTP can do just about anything that cUrl can do, and these new options make it even easier to make cUrl-based examples work in SAS.
The Google Analytics API is complex on its own, so I suggest that you spend some time in the Google API Explorer to see what types of requests yield what sort of results. Google Analytics allows you to fetch metrics across different dimensions and dates, so the results can come back summarized across the dimensions that you request. Since we're bringing this data into SAS and I probably want to further summarize in my reports, I try to get as much "unsummarized" data as possible, and I avoid aggregations such as "Average views" or "Average time on page" -- as I don't want to risk calculating new summaries based on these.
I've included my program for retrieving the page views, total time on page, entrances and exits at the daily level. This is granular enough for me to create meaningful reports all of our blog authors. The program is a SAS macro that issues one API call per day in the range specified.
/* Metrics and dimensions are defined in the Google Analytics doc */
/* Experiment in the developer console for the right mix */
/* Your scenario might be different and would require a different */
/* type of query */
/* The GA API will "number" the return elements as */
/* element1, element2, element3 and so on */
/* In my example, path and title will be 1 and 2 */
%let dimensions= %sysfunc(urlencode(%str(ga:pagePath,ga:pageTitle)));
/* then pageviews, uniquepageviews, timeonpage will be 3, 4, 5, etc. */
%let metrics= %sysfunc(urlencode(%str(ga:pageviews,ga:uniquePageviews,ga:timeOnPage,ga:entrances,ga:exits)));
/* this ID is the "View ID" for the GA data you want to access */
%let id= %sysfunc(urlencode(%str(ga:<your-view-ID>)));
%do workdate = &enddate %to &startdate %by -1;
filename ga_resp temp;
/* again, put this url= value ALL on a single line! */
/* Love this JSON libname engine! */
libname garesp json fileref=ga_resp;
data ga.ga_daily%sysfunc(compress(&urldate.,'-')) (drop=element:);
drop ordinal_root ordinal_rows;
length date 8 url $ 300 title $ 250
views 8 unique_views 8 time_on_page 8 entrances 8 exits 8
format date yymmdd10.;
/* Corerce the elements into data variables */
/* Basic on expected sequence */
url = element1;
title = element2;
views = input(element3, 5.);
unique_views = input(element4, 6.);
entrances = input(element6, 6.);
exits = input(element7, 6.);
/* Assemble the daily files into one data set */
When it's all finally working, SAS pulls in data that looks like this:
Re-entry and disclaimers
This has been a pretty deep post about Google APIs and how to make them work from SAS programs. If you have experience with the Google APIs already, then I'm optimistic that this article is enough for you to get things working in SAS. If you've never used OAuth2 or any of the Google APIs, then this post might not be quite enough. Don't forget to read Joseph's paper about OAuth2 and PROC HTTP. You might also like his paper about using RESTful APIs.
Please leave a comment if you have questions or if you think that I left something out. I'll do my best to correct and clarify.
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