iterate over a map key

RE: iterate over a map key

Mike Schmitt — Thu, 29 Aug 2024 14:29:40 GMT

remember that a!keys() grabs all keys (as a text array) in a particular dictionary, which you can grab into a local variable and then iterate over. As Stefan pointed out, you can't push new values into the existing map, but if (as your post implies) you only need to check which keys contain a certain value, then this should work fine. It should work similarly to Tim's suggested code except you wouldn't need to hardcode your key values in the "local!definedKeys" variable, you'd just use a!keys() there pointed to your map variable.

RE: iterate over a map key

Stefan Helzle — Thu, 29 Aug 2024 10:02:40 GMT

No. As variables in Appian are immutable, you cannot update anything during iterations. But using some of the set functions, you can easily do this.

RE: iterate over a map key

David Jimenez — Thu, 29 Aug 2024 09:23:20 GMT

If you always have the same keys...

local!key1: index(local!map, "key1"),
local!key2: index(local!map, "key2"),
local!key3: index(local!map, "key3"),

local!int1: union(intersection(local!key1, local!key2),intersection(local!key1, local!key2)),
local!int2: union(intersection(local!key1, local!key3),intersection(local!key1, local!key3)),
local!int3: union(intersection(local!key2, local!key3),intersection(local!key2, local!key3)),

local!int1 & "//" & local!int2 & "//" & local!int3

RE: iterate over a map key

Tim — Thu, 29 Aug 2024 08:23:03 GMT

If you define an array of your key names you can iterate over them with a nested a!forEach(). Example below, you can do what you want with the test and return value on the inner loop.

a!localVariables(
  local!map: {
    a!map(
      label: "Map 1",
      key1: "A",
      key2: "C",
      key3: "C"
    ),
    a!map(
      label: "Map 2",
      key1: "C",
      key2: "A",
      key3: "B"
    ),
    a!map(
      label: "Map 3",
      key1: "C",
      key2: "B",
      key3: "C"
    )
  },
  local!definedKeys: { "key1", "key2", "key3" },
  a!forEach(
    items: local!map,
    expression: a!localVariables(
      local!innerMap: fv!item,
      a!forEach(
        items: local!definedKeys,
        expression: if(
          local!innerMap[fv!item] ="C",
          fv!item,
          {}
        )
      )
    )
  )
)