How to convert CDT list into List of Varient

Considering that a!forEach() can act on any list type (including list of CDT), i'm not sure why you would want to do this - can you explain a bit more about your use case?

1.      In my process model I have a process variable of type 

you can also suggest some other ways or shortcut to make it done

my initial feedback is that you're misusing "fv!item[1]" (etc).  Each "fv!item" will be a single instance of your CDT but your square-bracket index calls make Appian want to treat "fv!item" like an array -- which it isn't.  So you'll need to fix that before this expression will work, regardless of the data type.

How can we parse 2-D array then? . In my case the variable contains:

[id=, name=pfizer, perCost=100, quantity=2, totalCost=200],[id=, name=cipla, perCost=120, quantity=2, totalCost=240],[id=, name=beta, perCost=90, quantity=1, totalCost=90],[id=, name=pathlabs, perCost=88, quantity=4, totalCost=352],[id=, name=nlabs, perCost=30, quantity=3, totalCost=90],[id=, name=cx100, perCost=230, quantity=2, totalCost=460],[id=, name=, perCost=, quantity=, totalCost=1432]

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I have load this data from excel with method below and it is working fine:

      a!localVariables(
         local!excelFile:readexcelsheet(
         excelDocument:ri!docId,
         sheetNumber:0,
         startRow:5
      ).result,
      local!excelinArray:a!flatten(local!excelFile),
      local!finalOut:a!forEach(
         items: local!excelinArray.values,
         expression:'type!{urn:com:appian:types:mb}MB_Medicine__Cost_Data_fromExcel'(
         name: fv!item[1],
         perCost: fv!item[2],
         quantity: fv!item[3],
         totalCost: fv!item[4]
      )
     ),
     local!finalOut

)

-------------------------------------------------

the problem comes after this when i want to change some values

How can we parse 2-D array then? . In my case the variable contains:

[id=, name=pfizer, perCost=100, quantity=2, totalCost=200],[id=, name=cipla, perCost=120, quantity=2, totalCost=240],[id=, name=beta, perCost=90, quantity=1, totalCost=90],[id=, name=pathlabs, perCost=88, quantity=4, totalCost=352],[id=, name=nlabs, perCost=30, quantity=3, totalCost=90],[id=, name=cx100, perCost=230, quantity=2, totalCost=460],[id=, name=, perCost=, quantity=, totalCost=1432]

----------------------------------------------------------------------------------------------------------

I have load this data from excel with method below and it is working fine:

      a!localVariables(
         local!excelFile:readexcelsheet(
         excelDocument:ri!docId,
         sheetNumber:0,
         startRow:5
      ).result,
      local!excelinArray:a!flatten(local!excelFile),
      local!finalOut:a!forEach(
         items: local!excelinArray.values,
         expression:'type!{urn:com:appian:types:mb}MB_Medicine__Cost_Data_fromExcel'(
         name: fv!item[1],
         perCost: fv!item[2],
         quantity: fv!item[3],
         totalCost: fv!item[4]
      )
     ),
     local!finalOut

)

-------------------------------------------------

the problem comes after this when i want to change some values

BTW, it's 20x easier to read code snippets if you use a Code Box (Insert --> Insert Code), as this preserves indentation and uses a monospace font and (if you select "Java" from the type dropdown) gives a little bit of syntactic highlighting.  (I have no idea why "Appian SAIL" or something similar still isn't an option there.)

akshays0003 said:

I have load this data from excel with method below and it is working fine:

I don't really know why this would be working at all - the square bracket indexes would not work at all as far as I know, unless they accidentally refer to the correct dot properties by position in this context, which I didn't know was possible (and even if it is seemingly working, I would NEVER recommend coding it this way).

I have checked it. It was working only when I use my CDT type in expression in foreach.

I have also tried one more thing when I don't use type! in expression. It just simply returns Type:List of variant and not storing any data in the process variable. fails the process earlier than before

So, I left with no other option instead of using type! in expression and brackets with fv!item

Here is probably our missing piece - your Excel data is coming in not as typed data, but rather an array of arrays of type text.  This is why "fv!item[3]", and similar, is giving you a working result.

Given this, your original code appears like it might not be as far off-base as I'd assumed.  What particular error message do you get when you try to execute the expression rule as originally written?

Also: can you confirm which Appian version you're currently using?

You are correct it is array of arrays of type text.from excel.

My Appian Verison is 20.3

I think I need to use something other than a! update as mentioned by u previously.

"   Note: if you're not yet in 21.2, a!update() will not be available but you can simply use updateDictionary() which is available in a plug-in.  "

What is the exact error you're getting when you run the code you posted originally?

What happens when you run the attached expression instead?  For temporary debugging I've swapped out the "read from excel" text list results with an array of JSON strings (Appian refuses to recreate a "array of text string arrays" otherwise by any other method I know of).  But other than the JSON conversion it should be analogous to your version.  The following worked for me (though I did have to swap out the type! call and just wrap the results in a plain dictionary) --

a!localVariables(
  local!dataInput: {
    a!toJson({ "pfizer", "100", "2", "200" }),
    a!toJson({ "cipla", "120", "3", "250" })
  },
  
  local!finalUpdate: a!forEach(
    items: local!dataInput,
    expression: a!localVariables(
      local!checking: "cipla",
      local!testItem:  a!fromJson(fv!item),
      
      'type!{urn:com:appian:types:mb}MB_Medicine__Cost_Data_fromExcel'(
        name: if(local!testItem[1] = local!checking, "ciplex", local!testItem[1]),
        perCost: local!testItem[2],
        quantity: local!testItem[3],
        totalCost: local!testItem[4]
      )
    )
  ),
  local!finalUpdate
)

If you're calling the expression rule on the CDT coming from the process variable, it will no longer be giving you the "array of text arrays" like in the original example, and therefore the code won't work for the reasons I mentioned in my original reply.  You're mixing up 2 pieces of functionality that work in 2 separate ways.