What determines the column order of a table data view mapping?

[absmiths]

In my capabilities.json, I have data roles defined like this:

"dataRoles": [
	{"displayName": "Measured Depth", "name": "measuredDepth", "kind": "Grouping"},
	{"displayName": "Is Planned", "name": "isPlanned", "kind": "Grouping"},
	{"displayName": "Is Actual", "name": "isActual", "kind": "Grouping"},
	{"displayName": "Depth Above", "name": "depthAbove", "kind": "Grouping"},
	{"displayName": "Planned TVD", "name": "plannedTrueVerticalDepth", "kind": "Grouping"},
	{"displayName": "Depth Below", "name": "depthBelow", "kind": "Grouping"},
	{"displayName": "Actual TVD", "name": "actualTrueVerticalDepth", "kind": "Grouping"},
	{"displayName": "Dog Leg Severity", "name": "dogLegSeverity", "kind": "Grouping"}
]

And my data view mapping looks like this:

"dataViewMappings": [{
	"table": {"rows": { "select": [
		{"for": {"in": "measuredDepth"}},
		{"for": {"in": "isPlanned"}},
		{"for": {"in": "isActual"}},
		{"for": {"in": "depthAbove"}},
		{"for": {"in": "plannedTrueVerticalDepth"}},
		{"for": {"in": "depthBelow"}},
		{"for": {"in": "actualTrueVerticalDepth"}},
		{"for": {"in": "dogLegSeverity"}}
	]}}
}]

And yet, when I look at my row data in the javascript debugger, the columns do not come in that order (abbreviated):

{
	"0": {"roles": {"isActual": true}},
	"1": {"roles": {"isPlanned": true}},
	"2": {"roles": {"depthAbove": true}},
	"3": {"roles": {"plannedTrueVerticalDepth": true}},
	"4": {"roles": {"depthBelow": true}},
	"5": {"roles": {"actualTrueVerticalDepth": true}},
	"6": {"roles": {"dogLegSeverity": true}},
	"7": {"roles": {"measuredDepth": true}}
}

Is this normal, or did I set something up wrong?  Do I need to scan the columns and dynamically locate my data points on each refresh?  I sort of thought the data view mapping would handle that.

[v-viig · Accepted solution]

Columns order depend on how you fill data-fields of your custom visual.

Custom visual must use roles property to detemine what column is.

Ignat Vilesov,

Software Engineer

Microsoft Power BI Custom Visuals

pbicvsupport@microsoft.com

[Anonymous]

@v-viig Can you give an example of how to use the 'roles' property to determine column? 

[dm-p]

Hi @Anonymous,

We've recently discussed this here, and this helped out the person making the post. See if this works for you and we can discuss further as necessary.

Good luck!

Daniel

[Anonymous]

@dm-p 

Thanks for the link.   I am using a table this time. e.g. dataView.table...what's the syntax to get the corresponding columns if it is table?  Thanks.

---

@dm-p wrote:

Hi @Anonymous,

We've recently discussed this here, and this helped out the person making the post. See if this works for you and we can discuss further as necessary.

Good luck!

Daniel

---

[dm-p]

Hi @Anonymous,

That post specifically deals with the dataView.table mapping, so not sure how much else I can provide without more targeted info. Might be better handling in a separate post that defines the issue more fully.

Failing that, I recently posted this on my website to walk through the mapping a bit further - not sure if it breaks it down more for you?

Regards,

Daniel

[Anonymous]

@dm-p 

Ah Yes.  Sorry I was reading a wrong post.  Got it now!  Thanks!  Your function is brilliant!

[absmiths]

Okay - not the answer I hoped for - but at least confirms my suspicion.  Perhaps this would be a good feature request since parsing column data and matching by name to the configured values will be a common activity (I would suspect).

[v-viig]

We'll consider this idea but it's pretty easy to implement by enumerating columns and checking role name.

Ignat Vilesov,

Software Engineer

Microsoft Power BI Custom Visuals

pbicvsupport@microsoft.com