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Anonymous's avatar
Anonymous
Not applicable
7 years ago
Solved

Delay web query until condition met from another web query

I use an API that provides a Json response which includes a statusUrl and a downloadUrl. If I immediately hit up the downloadUrl there is usually no data. The statusUrl Json response advises when t...
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  • Nolock's avatar
    Nolock
    7 years ago

    Hi Anonymous,

    I've prepared a template which you can use for solving your problem.

    You have to add your logic for processing JSON responses and modify the WaitForList according your needs.

    let
    // request data
    RequestDataRecord = fnProcessJson(Web.Contents("request data URL")),

    // wait 10x for 5 seconds
    WaitForList = List.Repeat({5}, 10),
        // wait until the response is COMPLETE, but max 50 secs
    WaitForStatus = List.MatchesAny(
            WaitForList,
            each 
                Function.InvokeAfter(
                    () => fnProcessJson(Web.Contents("http://StatusCheckURL")), 
                    #duration(0,0,0,_)
                ) = "COMPLETE"
            ),
    
    // download file if WaitForStatus was successful        
    DownloadFile =
        if WaitForStatus then
            fnProcessJson(Web.Contents("download data URL"))
        else
            null
in
    DownloadFile
Nolock's avatar
Nolock
Resident Rockstar
7 years ago

Hi Anonymous,

do you mean this function? 

() => fnProcessJson(Web.Contents("http://StatusCheckURL"))

The result should be the status (i.e. COMPLETE, INPROGRESS, FAILED, ...) and its datatype is text because I compare it with the string "COMPLETE" on the next line.

But you can modify the code in a form which fulfils all your expectations. It is just a template how it could work.

Anonymous's avatar
Anonymous
Not applicable
7 years ago
Yep, that's the function. So.. I created the function, the output is text "COMPLETE" .
I'm not sure what odds going wrong, I still get the "null" output.
  • Nolock's avatar
    Nolock
    Resident Rockstar
    7 years ago

    Hi Anonymous,

    a simplified version that waits just for one second and then returns "xxx". Maybe it helps.

    let
    // wait 10x for 5 seconds
    WaitForList = List.Repeat({1}, 10),
    WaitForStatus = List.MatchesAny(
            WaitForList,
            each 
                Function.InvokeAfter(
                    () => "COMPLETE", 
                    #duration(0,0,0,_)
                ) = "COMPLETE"
            ),
            
    DownloadFile =
        if WaitForStatus then
            "xxx"
        else
            null
in
    DownloadFile