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markslosberg
Level: Powered On

Can more than one argument be passed to a Flow from PowerApps?  If so, of course, how?

So I am plowing along, pretty successfully using what I learned in in this post  (https://powerapps.microsoft.com/en-us/blog/return-an-array-from-flow-to-powerapps-response-method/) to call an SQL stored procedure from a Flow and then call that Flow in turn from a PowerApp but I have encountered a roadblock and am not coming up with the right strategy to solve it.  Here is a step-by-step of where I am and I would be extremely appreciative of any direction someone could point me in.   I have been browsing those sites to answer the question ("Can I pass more than one argument from a PowerApp to a Flow that needs four).  While I have seen some similar posts (https://powerusers.microsoft.com/t5/Building-Power-Apps/PowerApp-Button-pass-2-seperate-parameters-t...), nothing that directly addresses this problem, which I suspect others are encountering from the variety of different posted questions.

 

I have created a SQL Server stored procedure that takes 4 string arguments that works successfully.

ALTER PROCEDURE [dbo].[FlexQueryProductInventory]
       @Salesperson varchar(50) = '',
       @Crop varchar(50) = '',
       @Variety varchar(50) = '',
       @WarehouseName varchar(50) = ''
AS
BEGIN
      SET NOCOUNT ON;
      SELECT [Company Number]
      ,[Company Name]
      ,[Bus Unit]
      ,[Bus Unit Desc]
      ,[LOCATION]
      ,[Item Nbr Short]
      ,[Item Number]
      ,[Item Desc01]
      ,[Item Desc02]
      ,[Unit of Measure]
     ,[Qty On Hand]
      ,[Qty In Transit]
      ,[Qty On PO]
      ,[Qty Commit]
      ,[Qty On Backorder]
      ,[Qty Available]
  FROM [BI_Mart].[dbo].[RT_Product_Inventory]
  WHERE
       [LOCATION] LIKE '%' + @Salesperson + '%' AND
       [Item Desc02] LIKE '%' + @Crop + '%' AND
       [Item Desc01] LIKE '%' + @Variety + '%' AND
       [Bus Unit Desc] LIKE '%' + @WarehouseName + '%'
  ORDER BY [LOCATION], [Item Desc02], [Item Desc01], [Bus Unit]
END

I have created a Flow to execute this.  I have not gotten this to execute completely correctly yet in test mode since it is only prompting me for a single variable instead of four.  If I enter a string during a test, it placed that into each variable and while it ran successfully, it didn’t return any rows (because of course the search criteria didn’t result in any matches).  I then created a simpler stored procedure with a single WHERE test that did test out successfully (which is where I got the JSON payload to feed to the Response step to generate the schema).  So I have not successfully executed this Flow with proper strings being fed to each of the four variables  which was perhaps a foreshadowing of the problem I am encountering.  I have fiddled around a little with the configuration of the Initialize Variable step but to no avail so far.

Flow with multiple parameter variables.pngFlow with multiple parameter variables

 

I then went into my PowerApps and started to configure the Button to call the Flow and there is where I have encountered the block. Notice the Invalid number of arguments: received 4, expected 1 error message.  This seemed eerily similar to my inability to test my Flow with more than one string entry (one for each variable).

 

(the screen shots are showing up in line so I have attached them as files to the bottom)

PowerApps calling Flow Error Message.png

 

Now we get to my question.  Can more than one argument be passed to a Flow from PowerApps?  If so, of course, how?  I am beginning to believe based on reading the posts that I might have to pass a concatenated CSV string to the Flow in one argument. Then I will have to make the Flow parse the single input string and populate each of the four variables, perhaps with the Split function which I don’t know how to do yet so I need to better understand that process too (as I suspect that will also be useful in the future).  But I am wondering if perhaps there is a different way to write the Flow from scratch to accept more than the one argument.  This seems like it should be straightforward but as we know very little is straightforward in PowerApps and Flow😉.

 

For just a little more context, here is the whole PowerApps app where I will populate the Data Table in the middle with the results of this stored procedure based on the search parameters passed and the lower Gallery with the results of the second stored procedure which fortunately only requires one variable to be passed after an item is selected from the Data Table.

OverallPowerAppsScreen.jpg

 
1 ACCEPTED SOLUTION

Accepted Solutions
markslosberg
Level: Powered On

Re: Can more than one argument be passed to a Flow from PowerApps?  If so, of course, how?

I finally solved this little mystery and the short answer is "Yes, you can pass more than one argument to a Flow from PowerApps but it doesn't seem to be documented anywhere".  Here is the short description:

 

I was on the right track in that you just put in an Initialize Variable step for each argument (variable) you want to pass and make certain that you select "Ask in PowerApps" from the Dynamics Content for each Value when prompted.  This is where it gets a little squirrely because while the "Ask in PowerApps" comes up initially in the Dynamic Content box on the first variable, it "disappears" for some reason in subsequent Initialize Variable steps.  It is there but hidden for some reason and you need to either query for it with an "Ask" or just hit the show more button.  When you do that, all is good and things work more or less as one might expect.

 

Now here are all of the "gotchas" that made this difficult to solve and generated an enormous amount of frustration.

This argument passing issue was really, really annoying because it pointed up

  1. the continued lack of documentation and inability to find a quick answer to what design pattern and syntax to use for something so straightforward that many people likely will need somewhere along the line.  All of the references come from people trying to solve their specific problem (like passing and parsing multiple email addresses) rather than the more general question of passing multiple arguments. There is a great white paper out there on standards and guidelines that has helped me a lot but it really needs to be expanded to include lots of really standard design patterns out there like this one (as well as clear documentation on how to use certain functions like split()).
  2. real deficiencies in the Power Automate and PowerApp  Studios and again a lack of a basic documentation including known issues. 
    1. In Power Automate, initialized variables are not taking on the names of steps in the Dynamics Content window that are renamed (or the variables that are being set) so it is completely impossible, after doing the renaming to real steps, to tell which step the data is being requested for during Test runs of the Flow
    2. Even worse, when I deleted Flow steps because I had bolluxed up the syntax so badly I wanted to start fresh on them, the “deleted” Initialized value remained somewhere in the Power Automate cache and I couldn’t find any documentation on how to clear them (I tried everything I could think of).  In addition, they continued to accumulate as you add and delete steps so the test went from prompting me for just one variable (out of the 4 I was looking for) to prompting me for 5 and then 9 and then 10, 11, 12 as I deleted steps to try to get back to a good starting point before re-adding them.  In addition, as I said earlier in this post, the “Ask from PowerApp” Dynamic Content showed up nicely for the first Initialize Variable step but then for unknown reasons went invisible on subsequent Initialize Variable steps.  It was there and I just had to hit “show more” or query for it but I only found it because I stumbled on it out of sheer frustration rather than having it clearly documented somewhere. 
      1. BTW, it turns out that happened to be my initial mistake.  Because I couldn’t find that option in the Dynamics Content window, I had tried something else when I initialized variables 2-4 the first time around and since I hadn’t used “Ask in PowerApps” on them then, guess what, it wasn’t asking for them😉.
    3. Finally, out of sheer desperation because I couldn’t clear out the old detritus variables, I had to completely start over with a fresh Flow from scratch determined not to make any mistakes now that I knew about this little variable caching issue.  Now, as a musician, I know that it was good for me to get the practice doing it over and over but as a person who actually wants a product to work in a reasonable manner and get to bed on time, that was definitely not what happened last night😉
  3. Then, just to top it all off, late in the evening, after I solved the Flow issue and just wanted to connect it up to my PowerApp to test, I discovered a major problem in the PowerApps Studio trying to invoke the Flow.  When I used the Action>Power Automate button, it repeatedly, completely erased and then garbled what I had entered into the function line initially (the ClearCollect function template).  Then when I redid I added the ClearCollect function back in, it deleted the Power Automate call.  I had to piece the function line text together with a series of “cuts and pastes” from Notepad (I mean like 5, I was ready to put my fist through the screen before I got it all assembled).  While I had gotten a little used to this type of strange Studio behavior 3 years ago, I was really not expecting this kind of thing to still be in the product now.  I really thought I was going crazy there for a few minutes until I stepped through it very, very slowly watching every single keystroke to see when it broke.

So as Willie the Shake would say "all's well that ends well".  And, had I needed to, I now know how I could have used the other strategy to solve the problem by passing a string with multiple values concatenated together as a CSV and then parse them out and assign them to Flow variables using the split() function which I couldn’t do before (and yet again, the documentation on how to do that was fragmented and found all over the place in different blog posts and messages).

 

I will try to come back into the post and add a few screenshots later if I have some time.

 

 

View solution in original post

3 REPLIES 3
Super User
Super User

Re: Can more than one argument be passed to a Flow from PowerApps?  If so, of course, how?

@markslosberg 

Did you try removing the Flow from PowerApps and then re-adding it?

 

---
Please click "Accept as Solution" if my post answered your question so that others may find it more quickly. If you found this post helpful consider giving it a "Thumbs Up."

markslosberg
Level: Powered On

Re: Can more than one argument be passed to a Flow from PowerApps?  If so, of course, how?

I did but not in a very controlled setting.  I really would like to know that I am on the correct structural track to solve this and then go back and execute the changes in carefully scripted setting to ensure that I am not flopping around (a technical term) and wasting a lot of time trying things willy-nilly.

markslosberg
Level: Powered On

Re: Can more than one argument be passed to a Flow from PowerApps?  If so, of course, how?

I finally solved this little mystery and the short answer is "Yes, you can pass more than one argument to a Flow from PowerApps but it doesn't seem to be documented anywhere".  Here is the short description:

 

I was on the right track in that you just put in an Initialize Variable step for each argument (variable) you want to pass and make certain that you select "Ask in PowerApps" from the Dynamics Content for each Value when prompted.  This is where it gets a little squirrely because while the "Ask in PowerApps" comes up initially in the Dynamic Content box on the first variable, it "disappears" for some reason in subsequent Initialize Variable steps.  It is there but hidden for some reason and you need to either query for it with an "Ask" or just hit the show more button.  When you do that, all is good and things work more or less as one might expect.

 

Now here are all of the "gotchas" that made this difficult to solve and generated an enormous amount of frustration.

This argument passing issue was really, really annoying because it pointed up

  1. the continued lack of documentation and inability to find a quick answer to what design pattern and syntax to use for something so straightforward that many people likely will need somewhere along the line.  All of the references come from people trying to solve their specific problem (like passing and parsing multiple email addresses) rather than the more general question of passing multiple arguments. There is a great white paper out there on standards and guidelines that has helped me a lot but it really needs to be expanded to include lots of really standard design patterns out there like this one (as well as clear documentation on how to use certain functions like split()).
  2. real deficiencies in the Power Automate and PowerApp  Studios and again a lack of a basic documentation including known issues. 
    1. In Power Automate, initialized variables are not taking on the names of steps in the Dynamics Content window that are renamed (or the variables that are being set) so it is completely impossible, after doing the renaming to real steps, to tell which step the data is being requested for during Test runs of the Flow
    2. Even worse, when I deleted Flow steps because I had bolluxed up the syntax so badly I wanted to start fresh on them, the “deleted” Initialized value remained somewhere in the Power Automate cache and I couldn’t find any documentation on how to clear them (I tried everything I could think of).  In addition, they continued to accumulate as you add and delete steps so the test went from prompting me for just one variable (out of the 4 I was looking for) to prompting me for 5 and then 9 and then 10, 11, 12 as I deleted steps to try to get back to a good starting point before re-adding them.  In addition, as I said earlier in this post, the “Ask from PowerApp” Dynamic Content showed up nicely for the first Initialize Variable step but then for unknown reasons went invisible on subsequent Initialize Variable steps.  It was there and I just had to hit “show more” or query for it but I only found it because I stumbled on it out of sheer frustration rather than having it clearly documented somewhere. 
      1. BTW, it turns out that happened to be my initial mistake.  Because I couldn’t find that option in the Dynamics Content window, I had tried something else when I initialized variables 2-4 the first time around and since I hadn’t used “Ask in PowerApps” on them then, guess what, it wasn’t asking for them😉.
    3. Finally, out of sheer desperation because I couldn’t clear out the old detritus variables, I had to completely start over with a fresh Flow from scratch determined not to make any mistakes now that I knew about this little variable caching issue.  Now, as a musician, I know that it was good for me to get the practice doing it over and over but as a person who actually wants a product to work in a reasonable manner and get to bed on time, that was definitely not what happened last night😉
  3. Then, just to top it all off, late in the evening, after I solved the Flow issue and just wanted to connect it up to my PowerApp to test, I discovered a major problem in the PowerApps Studio trying to invoke the Flow.  When I used the Action>Power Automate button, it repeatedly, completely erased and then garbled what I had entered into the function line initially (the ClearCollect function template).  Then when I redid I added the ClearCollect function back in, it deleted the Power Automate call.  I had to piece the function line text together with a series of “cuts and pastes” from Notepad (I mean like 5, I was ready to put my fist through the screen before I got it all assembled).  While I had gotten a little used to this type of strange Studio behavior 3 years ago, I was really not expecting this kind of thing to still be in the product now.  I really thought I was going crazy there for a few minutes until I stepped through it very, very slowly watching every single keystroke to see when it broke.

So as Willie the Shake would say "all's well that ends well".  And, had I needed to, I now know how I could have used the other strategy to solve the problem by passing a string with multiple values concatenated together as a CSV and then parse them out and assign them to Flow variables using the split() function which I couldn’t do before (and yet again, the documentation on how to do that was fragmented and found all over the place in different blog posts and messages).

 

I will try to come back into the post and add a few screenshots later if I have some time.

 

 

View solution in original post

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