QGIS/resources/function_help/json/is_selected

{
  "name": "is_selected",
  "type": "function",
  "groups": ["Record and Attributes"],
  "description": "Returns True if a feature is selected. Can be used with zero, one or two arguments, see below for details.",
  "variants": [{
    "variant": "No parameters",
    "variant_description": "If called with no parameters, the function will return true if the current feature in the current layer is selected.",
    "arguments": [],
    "examples": [{
      "expression": "is_selected()",
      "returns": "True if the current feature in the current layer is selected."
    }]
  }, {
    "variant": "One 'feature' parameter",
    "variant_description": "If called with a 'feature' parameter only, the function returns true if the specified feature from the current layer is selected.",
    "arguments": [{
      "arg": "feature",
      "description": "The feature which should be checked for selection."
    }],
    "examples": [{
      "expression": "is_selected(@atlas_feature)",
      "returns": "True if the current atlas feature is selected."
    }, {
      "expression": "is_selected(get_feature('streets', 'name', 'Main St.')))",
      "returns": "True if the unique named \"Main St.\" feature on the active \"streets\" layer is selected."
    }, {
      "expression": "is_selected(get_feature_by_id('streets', 1))",
      "returns": "True if the feature with the id 1 on the active \"streets\" layer is selected."
    }]
  }, {
    "variant": "Two parameters",
    "variant_description": "If the function is called with both a layer and a feature, it will return true if the specified feature from the specified layer is selected.",
    "arguments": [{
      "arg": "layer",
      "description": "The layer (its ID or name) on which the selection will be checked."
    }, {
      "arg": "feature",
      "description": "The feature which should be checked for selection."
    }],
    "examples": [{
      "expression": "is_selected( 'streets', get_feature('streets', 'name', \"street_name\"))",
      "returns": "True if the current building's street is selected (assuming the building layer has a field named 'street_name' and the 'streets' layer has a field called 'name' with unique values)."
    }, {
      "expression": "is_selected( 'streets', get_feature_by_id('streets', 1))",
      "returns": "True if the feature with the id 1 on the \"streets\" layer is selected."
    }]
  }],
  "tags": ["selected", "arguments", "details"]
}