Column Formatting using JSON (Sharepoint Online)

Question

I'm trying to inject some life into an old Sharepoint site (classic) by creating a new Progress Bar based on a %Complete field.

The new JSON template code provided by Microsoft doesnt seem to want to work on a Classic site, so any help with getting it or something similar to work is greatly appreciated.

I'm applying it to my field %Complete which is just a number field (it's populate via a workflow)

Current Code:

{
   "elmType":"div",
   "children":[
      {
         "elmType":"span",
         "txtContent":{
            "operator":"+",
            "operands":[
               {
                  "operator":"*",
                  "operands":[
                     "@currentField",
                     100
                  ]
               },
               " %"
            ]
         },
         "style":{
            "background-color":{
               "operator":"?",
               "operands":[
                  {
                     "operator":"<=",
                     "operands":[
                        "@currentField",
                        0.33
                     ]
                  },
                  "#ffa500",
                  {
                     "operator":"?",
                     "operands":[
                        {
                           "operator":"<=",
                           "operands":[
                              "@currentField",
                              0.66
                           ]
                        },
                        "#ffff00",
                        "#00ff00"
                     ]
                  }
               ]
            },
            "width":{
               "operator":"+",
               "operands":[
                  {
                     "operator":"*",
                     "operands":[
                        "@currentField",
                        100
                     ]
                  },
                  "%"
               ]
            },
            "text-align":"center"
         }
      }
   ]
}

Answer 1

As I understand it, using JSON for column formating only works on Modern sites. I spent a long time trying to get progress bars on Classic sites working with CSR and gave up. I'm sure someone who knows more will be along in a bit. Meantime here is a link to some more info on trying to make it work.