Vega tree layout error

[Ashvin_Bhutekar]

what is the reason behind this error "Infinite extent for field "depth": [Infinity, -Infinity]" in vega tree layout?

[rcowart (Rob Cowart)]

It happens when the query returned no data.

[Ashvin_Bhutekar]

I am new to vega! I want to create a tree layout from dynamically created documents. chat is the name of my Index pattern. botId, siteUrl , userid are fields in my index pattern. After writing below code I am getting "Infinite extent for field "depth" this error.
Please suggest me changes

{
"$schema": "https://vega.github.io/schema/vega/v5.json",
"description": "An example of Cartesian layouts for a node-link diagram of hierarchical data.",
"width": 600,
"height": 600,
"padding": 5,
"signals": [
{

  "name": "labels",
  "value": true,
  "bind": {
    "input": "checkbox"
  }
},
{
  "name": "layout",
  "value": "tidy",
  "bind": {
    "input": "radio",
    "options": [
      "tidy",
      "cluster"
    ]
  }
},
{
  "name": "links",
  "value": "diagonal",
  "bind": {
    "input": "select",
    "options": [
      "line",
      "curve",
      "diagonal",
      "orthogonal"
    ]
  }
},
{
  "name": "separation",
  "value": false,
  "bind": {
    "input": "checkbox"
  }
}

],
"data": [
{
"name" :"table"
"url": {
"%context%": true,
"%timefield%": "createdAt",
"index": "chat*",
"body": {
"aggs": {
"time_buckets": {
"date_histogram": {
"field": "chat*",
"interval": {"%autointerval%": true},
"extended_bounds": {
"min": {"%timefilter%": "min"},
"max": {"%timefilter%": "max"}
},
"min_doc_count": 0
}
}
},
"size": 0
} }
"format": {"property": "hits.hits"
} ,
"transform": [
{
"type": "fold",
"fields": [
"_source.botId",
"userId",
"siteUrl",
"nextSiteUrl"
]
},
{
"type": "formula",
"as": "id",
"expr": "datum.key == '_source.botId' ? datum._source.botId : datum.key == 'userId' ? join([datum.botId,datum.userId],'-') : datum.key == 'siteUrl' ? join([datum.botId, datum.userId, datum.siteurl],'-') : datum.key == 'nextSiteUrl' ? join([datum.botId, datum.userId, datum.siteUrl, datum.nextSiteUrl],'-') : null"
},
{
"type": "formula",
"as": "parent",
"expr": "datum.key == 'botId' ? null : datum.key == 'userId' ? datum.botId : datum.key == 'siteUrl' ? join([datum.botId, datum.userId],'-') : datum.key == 'nextSiteUrl' ? join([datum.botId, datum.userId, datum.siteUrl],'-') : null"
},
{
"type": "filter",
"expr": "isDefined(datum.value)"
},
{
"type": "aggregate",
"groupby": [
"id",
"parent"
]
},
{
"type": "formula",
"as": "label",
"expr": "peek(split(datum.id,'-'))"
}
]
},
{
"name": "tree",
"source": "table",
"transform": [
{
"type": "stratify",
"key": "id",
"parentKey": "parent"
},
{
"type": "tree",
"method": {
"signal": "layout"
},
"size": [
{
"signal": "height"
},
{
"signal": "width - 100"
}
],
"separation": {
"signal": "separation"
},
"as": [
"y",
"x",
"depth",
"children"
]
}
]
},
{
"name": "links",
"source": "tree",
"transform": [
{
"type": "treelinks"
},
{
"type": "linkpath",
"orient": "horizontal",
"shape": {
"signal": "links"
}
}
]
}
],
"scales": [
{
"name": "color",
"type": "linear",
"range": {
"scheme": "magma"
},
"domain": {
"data": "tree",
"field": "depth"
},
"zero": true
}
],
"marks": [
{
"type": "path",
"from": {
"data": "links"
},
"encode": {
"update": {
"path": {
"field": "path"
},
"stroke": {
"value": "#ccc"
}
}
}
},
{
"type": "symbol",
"from": {
"data": "tree"
},
"encode": {
"enter": {
"size": {
"value": 100
},
"stroke": {
"value": "#fff"
}
},
"update": {
"x": {
"field": "x"
},
"y": {
"field": "y"
},
"fill": {
"scale": "color",
"field": "depth"
}
}
}
},
{
"type": "text",
"from": {
"data": "tree"
},
"encode": {
"enter": {
"text": {
"field": "label"
},
"fontSize": {
"value": 9
},
"baseline": {
"value": "middle"
}
},
"update": {
"x": {
"field": "x"
},
"y": {
"field": "y"
},
"dx": {
"signal": "datum.children ? -7 : 7"
},
"align": {
"signal": "datum.children ? 'right' : 'left'"
},
"opacity": {
"signal": "labels ? 1 : 0"
}
}
}
}
]
}