Course Registration

{
  "$schema": "https://developer.microsoft.com/json-schemas/sp/v2/column-formatting.schema.json",
  "elmType": "div",
  "style": {
    "flex-directon": "row",
    "justify-content": "left",
    "align-items": "center",
    "flex-wrap": "nowrap"
  },
  "children": [
    {
      "elmType": "div",
      "style": {
        "display": "=if(indexOf([$PeopleWhoRegistered.email], @me) == -1 && length([$PeopleWhoRegistered]) != [$NumberOfPlaces] && @now <= [$RegistrationEndDate], '','none')",
        "flex-directon": "row",
        "justify-content": "left",
        "align-items": "center",
        "flex-wrap": "wrap"
      },
      "children": [
        {
          "elmType": "button",
          "customRowAction": {
            "action": "setValue",
            "actionInput": {
              "PeopleWhoRegistered": "=appendTo([$PeopleWhoRegistered], @me)"
            }
          },
          "attributes": {
            "class": "ms-fontColor-themePrimary ms-fontColor-themeDarker--hover",
            "title": "Register"
          },
          "style": {
            "border": "none",
            "background-color": "transparent",
            "cursor": "pointer",
            "display": "flex",
            "flex-directon": "row",
            "justify-content": "left",
            "align-items": "center",
            "flex-wrap": "wrap"
          },
          "children": [
            {
              "elmType": "span",
              "attributes": {
                "iconName": "AddTo"
              },
              "style": {
                "padding": "0px"
              }
            }
          ]
        }
      ]
    },
    {
      "elmType": "div",
      "style": {
        "display": "=if(indexOf([$PeopleWhoRegistered.email], @me) > -1 && @now <= [$RegistrationEndDate], '','none')",
        "flex-directon": "row",
        "justify-content": "left",
        "align-items": "center",
        "flex-wrap": "wrap"
      },
      "children": [
        {
          "elmType": "button",
          "customRowAction": {
            "action": "setValue",
            "actionInput": {
              "PeopleWhoRegistered": "=removeFrom([$PeopleWhoRegistered], @me)"
            }
          },
          "attributes": {
            "class": "ms-fontColor-themePrimary ms-fontColor-themeDarker--hover",
            "title": "Unregister"
          },
          "style": {
            "border": "none",
            "background-color": "transparent",
            "cursor": "pointer",
            "display": "flex",
            "flex-directon": "row",
            "justify-content": "left",
            "align-items": "center",
            "flex-wrap": "wrap"
          },
          "children": [
            {
              "elmType": "span",
              "attributes": {
                "iconName": "Blocked12"
              },
              "style": {
                "padding": "0px"
              }
            }
          ]
        }
      ]
    },
    {
      "elmType": "div",
      "children": [
        {
          "elmType": "span",
          "txtContent": "Registered",
          "style": {
            "display": "=if([$RegistrationEndDate] > @now && indexOf([$PeopleWhoRegistered.email], @me) > -1, '','none')",
            "padding-left": "5px",
            "word-break": "keep-all"
          }
        }
      ]
    },
    {
      "elmType": "div",
      "children": [
        {
          "elmType": "span",
          "txtContent": "Course is full",
          "style": {
            "display": "=if([$RegistrationEndDate] > @now && length([$PeopleWhoRegistered]) >= [$NumberOfPlaces], '','none')",
            "padding-left": "5px",
            "word-break": "keep-all"
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      ]
    },
    {
      "elmType": "div",
      "children": [
        {
          "elmType": "span",
          "txtContent": "Registration has ended",
          "style": {
            "display": "=if([$RegistrationEndDate] > @now, 'none','inherit')",
            "padding-left": "5px",
            "word-break": "keep-all"
          }
        }
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  ]
}