Last week I showed how you could use the WebService() function in Excel 2013 to bring location data into Excel 2013. Since this is a topic I have a particular interest in, this week I’ll show you how to do the same thing all over again but in Data Explorer.

First of all, a simple example. In that previous post I used the Google Distance Matrix API to calculate the distance between two points; for example the following call shows how long it would take me to drive from my home to Buckingham Palace to see the Queen (52 minutes in case you’re wondering):
http://maps.googleapis.com/maps/api/distancematrix/xml?origins=HP66HF&destinations=SW1A1AA&mode=driving&sensor=false

The following post on the Data Explorer forum from James Terwilliger gives some helpful tips on how to consume web services from within Data Explorer:
http://social.msdn.microsoft.com/Forums/en-US/dataexplorer/thread/069b50e3-ab9e-4ee4-99a9-23440fcfc768

…but it’s not altogether straightforward. For example if you paste the link above into the From Web data source, you do get something returned but it’s extremely hard to find any useful data. Instead, I found the following steps worked:

• First, hit From Web and enter something in the URL box:
  
• This gives you a new web query, but you want to discard any auto-generated code in the first step. Instead, paste the following expression:

  = Xml.Document(
  Web.Contents(“http://maps.googleapis.com/maps/api/distancematrix/xml”
  , [Query = [ origins= "HP66HF", destinations = "SW1A1AA", mode = "driving", sensor = "false" ] ]))

  

  This uses Web.Contents() to call the web service (as described in that forums reply) with the appropriate parameters. Xml.Document() is then used to interpret the response as an XML document.

• With this done, it’s quite easy to navigate through the XML by clicking on the Table links in each step to find the useful data:
  
• And finally hit Done to surface it the worksheet:
  

Some thoughts at this point: I don’t like the way the DE formula language is case-sensitive, and I suspect in the long run it will have to be either hidden or replaced with VBA or Excel formula language/DAX if it’s going to be used even by Excel power users. It is very, very powerful though, and luckily the UI is good enough to mean that 99% of users will never need to write DE formula language anyway.

The next question: I’ve hard-coded my origins and destinations in this example, but how can I read these values from the worksheet without my users having to open Data Explorer and edit the query? Tune in for Part 2 to find out!

Chris Webb’s BI Blog

Don’t you hate it when you get ready to blog about something cool, and then someone comes along and beats you to it? That’s what’s just happened to me – Matt Masson just wrote an excellent blog post on how to do address lookup against a web service here:
http://www.mattmasson.com/2013/03/dynamic-lookups-with-data-explorer/
That’s what I was going to write about in part 2 of this series. I have to say he did a better job than I would have done though, and shows off several cool tricks I hadn’t seen before…

Ah well, so it goes – and anyway there are a few things I was going to say that are still worth saying. If you remember, in Part 1 I showed how to call the Google Distance Matrix API from Data Explorer, but I hard-coded the start and end points in the expression I used. How can you get the start and end points directly from Excel? Well it turns out that Data Explorer can read values direct from Excel tables.

To start with, you need to create some Excel tables to hold the values you want to use. I created two Excel tables called Origin and Destination to hold the two values I needed:

I can then take the value from the first row in the sole column of each table (which are again called Origin and Destination, as you can see) by using

Excel.CurrentWorkbook(){[Name="Origin"]}[Content]{0}[Origin]

and

Excel.CurrentWorkbook(){[Name="Destination"]}[Content]{0}[Destination]

Here’s the full source expression with the hard-coded values replaced:

=
Xml.Document(
Web.Contents(
“http://maps.googleapis.com/maps/api/distancematrix/xml”
, [Query = [
origins= Excel.CurrentWorkbook(){[Name="Origin"]}[Content]{0}[Origin]
, destinations = Excel.CurrentWorkbook(){[Name="Destination"]}[Content]{0}[Destination]
, mode = “driving”, sensor = “false” ] ]))

Now, you can enter any address in the Origin and Destination tables, click Refresh on the Query as shown in the screenshot below:

And the query will be rerun with the new parameters. Note that it might also be a good idea to URL encode any text that you enter in these tables, using the EncodeURL() Excel function; I haven’t done so here because I’m using UK postcodes, which don’t need URL encoding, as my origins and destinations to make things simple.

It’s also possible to use the results of one query inside another query. Data Explorer allows you to use an Excel table as the source for a query:

And selecting the Destination Excel table as a source gives the following expression:

= Excel.CurrentWorkbook(){[Name="Destination"]}[Content]

The easy way to use any value from an existing query as the starting point for a new query is to right-click on a cell and select Add As New Query:

Doing this creates a new query with the value you clicked on a source:

Here’s the expression for the only step in the newly-created query:

= Destination{0}[Destination]

Even if this new query isn’t any use on its own, the expression shown here can be used in other queries. Here’s the original web service call adapted to use two other queries as its source:

= Xml.Document(
Web.Contents(
“http://maps.googleapis.com/maps/api/distancematrix/xml”
, [Query = [
origins= Origin{0}[Origin]
, destinations = Destination{0}[Destination]
, mode = “driving”, sensor = “false” ] ]))

However, as Matt shows in his post, this only works if Fast Combine is enabled, otherwise you’ll see an error message.

You can download the sample workbook for this post here.

Chris Webb’s BI Blog