Forum Discussion
Navigator window not displaying function input parameters. Custom Connector for Power BI
Hi,
I am trying to create a custom connector for Power BI. I have followed the documentation on how to set up
a Navigation Table. The table will navigate to three different functions.
I have set up the code accordingly. However, the UI for the function inputs is not generated in the Navigator window. Rather I am seeing this:
I see the UI just fine in the Power Query Editor. Here is my implementation of some test code:
[DataSource.Kind="PQExtension1", Publish="PQExtension1.Publish"]
shared PQExtension1.Contents = () as table =>
let
objects = #table(
{"Name", "Key", "Data", "ItemKind", "ItemName", "IsLeaf"},{
{"Item1", "item1", PQExtension1.GetSeries, "Function", "Function", true}
}),
NavTable = Table.ToNavigationTable(objects, {"Key"}, "Name", "Data", "ItemKind", "ItemName", "IsLeaf")
in
NavTable;
[DataSource.Kind = "PQExtension1"]
shared PQExtension1.GetSeries = () => Value.ReplaceType(HelloWorldImpl, HelloWorldType)
HelloWorldType = type function (
message as (type text meta [
Documentation.FieldCaption = "Message",
Documentation.FieldDescription = "Text to display",
Documentation.SampleValues = {"Hello world", "Hola mundo"}
]),
optional count as (type number meta [
Documentation.FieldCaption = "Count",
Documentation.FieldDescription = "Number of times to repeat the message",
Documentation.AllowedValues = { 1, 2, 3 }
]))
as table meta [
Documentation.Name = "Hello - Name",
Documentation.LongDescription = "Hello - Long Description",
Documentation.Examples = {[
Description = "Returns a table with 'Hello world' repeated 2 times",
Code = "HelloWorldWithDocs.Contents(""Hello world"", 2)",
Result = "#table({""Column1""}, {{""Hello world""}, {""Hello world""}})"
],[
Description = "Another example, new message, new count!",
Code = "HelloWorldWithDocs.Contents(""Goodbye"", 1)",
Result = "#table({""Column1""}, {{""Goodbye""}})"
]}
];
HelloWorldImpl = (message as text, optional count as number) as table =>
let
_count = if (count <> null) then count else 5,
listOfMessages = List.Repeat({message}, _count),
table = Table.FromList(listOfMessages, Splitter.SplitByNothing())
in
table;
I appreciate any help on this. I have seen similar posts here in the Power BI forum but clear solutions have not been given.
So I found a solution from the PowerBI REST API connector project. Basically you need a special implementation of the Table.ToNavigationTable function. It seems that you need to delete the "Preview.DelayColumn = itemNameColumn" from Table.ToNavigationTable .
This implementation of the navigation table works:
Table.ForceToNavigationTable = ( table as table, keyColumns as list, nameColumn as text, dataColumn as text, itemKindColumn as text, itemNameColumn as text, isLeafColumn as text ) as table => let tableType = Value.Type(table), newTableType = Type.AddTableKey(tableType, keyColumns, true) meta [ NavigationTable.NameColumn = nameColumn, NavigationTable.DataColumn = dataColumn, NavigationTable.ItemKindColumn = itemKindColumn, NavigationTable.IsLeafColumn = isLeafColumn ], navigationTable = Value.ReplaceType(table, newTableType) in navigationTable;The only problem I have now is that the documentation is not shown in the Navigator window:
In the Power Query Editor it looks like this:
7 Replies
So I found a solution from the PowerBI REST API connector project. Basically you need a special implementation of the Table.ToNavigationTable function. It seems that you need to delete the "Preview.DelayColumn = itemNameColumn" from Table.ToNavigationTable .
This implementation of the navigation table works:
Table.ForceToNavigationTable = ( table as table, keyColumns as list, nameColumn as text, dataColumn as text, itemKindColumn as text, itemNameColumn as text, isLeafColumn as text ) as table => let tableType = Value.Type(table), newTableType = Type.AddTableKey(tableType, keyColumns, true) meta [ NavigationTable.NameColumn = nameColumn, NavigationTable.DataColumn = dataColumn, NavigationTable.ItemKindColumn = itemKindColumn, NavigationTable.IsLeafColumn = isLeafColumn ], navigationTable = Value.ReplaceType(table, newTableType) in navigationTable;The only problem I have now is that the documentation is not shown in the Navigator window:
In the Power Query Editor it looks like this:
Hi, I have a similar problem.
My function has a record type parameter like this
but in the navigation table it looks like this
Hi Anonymous ,
Please refer the following links to get it:
Handling navigation for Power Query connectors | Microsoft Docs
shared NavigationTable.Simple = () => let objects = #table( {"Name", "Key", "Data", "ItemKind", "ItemName", "IsLeaf"},{ {"Item1", "item1", #table({"Column1"}, {{"Item1"}}), "Table", "Table", true}, {"Item2", "item2", #table({"Column1"}, {{"Item2"}}), "Table", "Table", true}, {"Item3", "item3", FunctionCallThatReturnsATable(), "Table", "Table", true}, {"MyFunction", "myfunction", AnotherFunction.Contents, "Function", "Function", true} }), NavTable = Table.ToNavigationTable(objects, {"Key"}, "Name", "Data", "ItemKind", "ItemName", "IsLeaf") in NavTable; shared FunctionCallThatReturnsATable = () => #table({"DynamicColumn"}, {{"Dynamic Value"}});Custom Connector and Navigation Tables
GetRows = () => if (state <> null) then state else let list = listFunction(), withName = Table.FromRecords(list, {"Name", "ItemKind", "Parameters"}, MissingField.UseNull), withData = Table.AddColumn(withName, "Data", each dataFunction([Name], [Parameters])), withItemName = Table.AddColumn(withData, "ItemName", each if [Parameters] = null or Record.FieldCount([Parameters]) = 0 then "Table" else null), withoutParameters = Table.RemoveColumns(withItemName, {"Parameters"}), withIsLeaf = Table.AddColumn(withoutParameters, "IsLeaf", each isLeaf), navTable = Table.ToNavigationTable(withIsLeaf, {"Name"}, "Name", "Data", "ItemKind", "ItemName", "IsLeaf") in navTableBest Regards
Hi,
The examples you have given are with functions that does not implement parameters. I have implemented the NavigationTable function from Handling navigation for Power Query connectors | Microsoft Docs. For instance, if I add a parameter to FunctionCallThatReturnATable then I get the same "No Paramters Specified"-Window in the Navigator. Why does the Preview window not allow me to generate the function UI. In the Power Query editor it works just fine.shared NavigationTable.Simple = () => let objects = #table( {"Name", "Key", "Data", "ItemKind", "ItemName", "IsLeaf"},{ {"Item1", "item1", #table({"Column1"}, {{"Item1"}}), "Table", "Table", true}, {"Item2", "item2", #table({"Column1"}, {{"Item2"}}), "Table", "Table", true}, {"Item3", "item3", (t as text) => FunctionCallThatReturnsATable(t), "Table", "Table", true}, {"MyFunction", "myfunction", AnotherFunction.Contents, "Function", "Function", true} }), NavTable = Table.ToNavigationTable(objects, {"Key"}, "Name", "Data", "ItemKind", "ItemName", "IsLeaf") in NavTable; shared FunctionCallThatReturnsATable = (t as text) => #table({"DynamicColumn"}, {{t}});
