Using Dynamic variables in aggregate query from Vega (in Kibana) to ElasticSearch - elasticsearch

Question

We have a report that fetches data from elasticsearch and displays them as buckets. We want to show a band, customers and profit amount for each band. The idea is that we should give a band size parameter and then Vega should create 5 buckets for that when querying the data. If I mention the band size to be 50, then vega will pass this on in the query and create buckets 0-50, 51 to 100, 101 to 150, 151 to 200 and 200+. I am really struggling with this a lot and can not make it work. I am pasting the vega script here that works with hard coded values but when it comes to doing it through signals, I have not reached any clue at all. I would like to use the value from signal to define to band parameter. Please help.
{
"$schema":"https://vega.github.io/schema/vega/v4.json",
"data":[
{
"name":"SalesData",
"url":{
"index":"orderaggregates",
"body":{
"size":0,
"aggs":{
"bands":{
"range":{
"field":"total_sales",
"ranges":[
{
"from":0,
"to":50
},
{
"from":50.01,
"to":100
},
{
"from":100.01,
"to":150
},
{
"from":150.01,
"to":200
},
{
"from":200.01
}
]
},
"aggs":{
"total_sales":{
"sum":{
"field":"total_sales"
}
},
"customers":{
"cardinality":{
"field":"user_id"
}
},
"confirmed_orders":{
"sum":{
"field":"confirmedorders"
}
},
"cost_total":{
"sum":{
"field":"cost_total"
}
},
"shipping_collected":{
"sum":{
"field":"freightcollected"
}
},
"shipping_paid":{
"sum":{
"field":"freight_paid"
}
}
}
}
}
}
},
"format":{
"property":"aggregations.bands.buckets"
},
"transform":[
{
"type":"project",
"fields":[
"key",
"doc_count",
"customers.value",
"cost_total.value",
"total_sales.value"
],
"as":[
"range",
"orders",
"customers",
"costs",
"sales"
]
},
{
"type":"identifier",
"as":"id"
},
{
"type":"formula",
"as":"y",
"expr":"datum.id * 30"
},
{
"type":"formula",
"as":"orders",
"expr":"format(datum.orders,',.0f')"
},
{
"type":"formula",
"as":"customers",
"expr":"format(datum.customers,',.0f')"
},
{
"type":"formula",
"as":"costs",
"expr":"format(datum.costs,'$,.0f')"
},
{
"type":"formula",
"as":"sales",
"expr":"format(datum.sales,'$,.0f')"
}
]
}
],
"signals":[
{
"name":"Group",
"value":40,
"bind":{
"input":"range",
"min":10,
"max":100,
"step":10
}
},
{
"name":"GroupSize",
"update":"Group/2"
}
],
"marks":[
{
"from":{
"data":"SalesData"
},
"type":"text",
"encode":{
"enter":{
"fill":{
"value":"#000"
},
"text":{
"field":"range"
},
"x":{
"value":50
},
"y":{
"field":"y"
}
},
"update":{
"opacity":{
"value":1
},
"fontSize":{
"signal":"GroupSize"
}
},
"hover":{
"opacity":{
"value":0.5
}
}
}
},
{
"from":{
"data":"SalesData"
},
"type":"text",
"encode":{
"enter":{
"fill":{
"value":"#000"
},
"text":{
"field":"customers"
},
"x":{
"value":250
},
"y":{
"field":"y"
}
},
"update":{
"opacity":{
"value":1
},
"fontSize":{
"signal":"GroupSize"
}
},
"hover":{
"opacity":{
"value":0.5
}
}
}
},
{
"from":{
"data":"SalesData"
},
"type":"text",
"encode":{
"enter":{
"fill":{
"value":"#000"
},
"text":{
"field":"orders"
},
"x":{
"value":350
},
"y":{
"field":"y"
}
},
"update":{
"opacity":{
"value":1
},
"fontSize":{
"signal":"GroupSize"
}
},
"hover":{
"opacity":{
"value":0.5
}
}
}
},
{
"from":{
"data":"SalesData"
},
"type":"text",
"encode":{
"enter":{
"fill":{
"value":"#000"
},
"text":{
"field":"sales"
},
"x":{
"value":450
},
"y":{
"field":"y"
}
},
"update":{
"opacity":{
"value":1
},
"fontSize":{
"signal":"GroupSize"
}
},
"hover":{
"opacity":{
"value":0.5
}
}
}
}
]
}

Answer 1

You have to change the structure. Move the task which is done in your query to data's transform section where you can use the signals:
Query all relevant data
Transform your data with usage of your signal "Group" to the bins (e.g. calculate "extend" and "bin" transforms similar to this: http://blog.wafrat.com/building-a-log-scaled-histogram-of-aaves-loans-in-vega/)