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Displaying Help For A Power Query Function

with one comment

Matt Masson and Theresa Palmer gave an excellent presentation on Power Query and M for the PASS DW/BI Virtual Chapter a few days ago (hopefully it will be on their YouTube channel soon). One thing that they showed which I hadn’t seen before was that you can display help for a function in M’s built in library simply by typing its name in the formula bar.

Take, for example, the Text.Replace() function. With a new blank query, if you create a step with the following definition:

= Text.Replace

You will see help and examples as shown below:

image

By doing this you are creating a step that returns the function itself – note that this is not the same as invoking the function, although it does mean you can invoke the function in a subsequent step. If you do decide to use the function you just need to click Invoke and a dialog will appear to prompt you for the values to pass to the function:

image

Clicking OK will show the output of the function:

image

Here’s the full M code for the query for those of you who are curious:

let

    Source = Text.Replace,

    InvokedSource = Source("the cat sat on the mat", "cat", "dog")

in

    InvokedSource

A very useful tip! Unfortunately you can’t specify help text for your own functions yet, although Matt did say it was something they wanted to do.

Written by Chris Webb

May 1, 2014 at 9:30 am

Posted in Power Query

One Response

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  1. Verty Nice!

    Mike Alexander

    May 1, 2014 at 7:46 pm


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