JSON Sharepoint Calculated Columns

Question

First time coding with JSON and need a little help...... I am attempting to make a calculated column with conditional formatting. So far i can get it to work but only partially. What i want is to have all cells default to green when empty (basic code), but change color based on the value.....

Basic Code Works

{
    "$schema": "https://developer.microsoft.com/json-schemas/sp/column-formatting.schema.json",
    "elmType": "div",
    "style": {
        "color": "#ffffff",
        "padding-left": "10px",
        "background-color": "#0000ff"
    },
    "children": [{
            "elmType": "span",
            "txtContent": "$ ",
            "style": {
                "display": "inline-block",
                "padding": "0 1px"
            }
        },
        {
            "elmType": "span",
            "txtContent": "[$cSDP_x0020_Hardware_x0020_Varian]",
            "attributes": {
                "class": ""
            }
        }
    ]
}

But when i add an if statement the conditions work but the empty cells do not turn green.....

{
    "$schema": "https://developer.microsoft.com/json-schemas/sp/column-formatting.schema.json",
    "elmType": "div",
    "style": {
        "color": "#000000",
        "padding-left": "10px",
            "background-color": "= if(@currentField < 0 ,'#CB4335',  if(@currentField < ([$cSDP_x0020_Hardware_x0020_Budget] * 0.15) ,'#FFC7CE', if(@currentField < ([$cSDP_x0020_Hardware_x0020_Budget] * 0.3),'#FFEB9C', '#dff6dd'))"
    },


    "children": [{
            "elmType": "span",
            "txtContent": "$ ",
            "style": {
                "display": "inline-block",
                "padding": "0 1px"
            }
        },
        {
            "elmType": "span",
            "style": {
                "overflow": "hidden",
                "text-overflow": "ellipsis",
                "padding": "0 3px"
            },
            "txtContent": "[$cSDP_x0020_Hardware_x0020_Varian]",
            "attributes": {
                "class": ""
            }

        }
    ]

}

The column/field the formula is evaluating is a calculated number field and I am wondering if that has anything to do with it? I have played around with simple calculations as well and can not seem to even evaluate a value as "0", null, or '' in the if statement.

I have been at this for a few days trying different ways to get it to work and feel i must be missing something simple in the code? I really hope this isn't a stupid SharePoint limitation situation.....

Thanks for your help!

Screenshot #3

Answer 1

Replace the current IF condition in the Background attribute with the below one:

=  if((@currentField == 0) || (@currentField.length == 0),'#dff6dd',if(@currentField < 0 ,'#CB4335',if((@currentField <= ([$cSDP_x0020_Hardware_x0020_Budget] * 0.15)) && (@currentField > 0),'#FFC7CE',if((@currentField <= ([$cSDP_x0020_Hardware_x0020_Budget] * 0.3)) && (@currentField > 0),'#FFEB9C',''))))

Output

As you can see, the empty cell has been highlighted with white green background as you need!

Check also, JSON SharePoint Date Column Formatting in SharePoint 2019 and SharePoint Online