Examples

Examples in Examples.json file below demonstrate logical operators described in Value is Null or Undefined Check Operators

Note

The following JSON files are referenced in JsonQL expressions in Examples.json in example below:

• Data.json

• Companies.json

{
  "Operator_is_null": {
    "Comment_Operator_is_null_1": "(invalid.path is null) evaluates to false. For invalid path check use 'is undefined' operator",
    "Operator_is_null_1": "$value(invalid.path is null == false)",
    "Operator_is_null_2": "$value(NullValue is null)",
    "Operator_is_null_3": "$value(Int1 is null == false)",
    "Operator_is_null_5": "$value(Companies.Select(c => c.Employees).First() is null == false)",

    "Comment_Operator_is_null_6_1": "Even though the query below results in no employee being selected. The value is not null",
    "Comment_Operator_is_null_6_2": "'is null' succeeds if there is JsonPath with null value.",
    "Comment_Operator_is_null_6_3": "'Use 'is undefined' instead to check if query resulted in any value",
    "Operator_is_null_6": "$value(Companies.Select(c => c.Employees).First(e => e.Age > 200) is null == false)"
  },
  "Operator_is_not_null": {
    "Comment_Operator_is_not_null_1": "(invalid.path is not null) evaluates to true.",
    "Operator_is_not_null_1": "$value(invalid.path is not null)",
    "Operator_is_not_null_2": "$value(NullValue is not null == false)",
    "Operator_is_not_null_3": "$value(Int1 is not null)",
    "Operator_is_not_null_5": "$value(Companies.Select(c => c.Employees).First() is not null)",
    "Operator_is_not_null_6": "$value(Companies.Select(c => c.Employees).First(e => e.Age > 200) is not null)"
  },
  "Operator_is_undefined": {
    "Comment_Operator_is_undefined_1": "(invalid.path is undefined) evaluates to true.",
    "Operator_is_undefined_1": "$value(invalid.path is undefined)",
    "Operator_is_undefined_2": "$value(NullValue is undefined == false)",
    "Operator_is_undefined_3": "$value(Int1 is undefined == true)",
    "Operator_is_undefined_5": "$value(Companies.Select(c => c.Employees).First() is undefined == false)",
    "Operator_is_undefined_6": "$value(Companies.Select(c => c.Employees).First(e => e.Age > 200) is undefined)"
  },
  "Operator_is_ not_undefined": {
    "Comment_Operator_is_not_undefined_1": "(invalid.path is not undefined) evaluates to false.",
    "Operator_is_not_undefined_1": "$value(invalid.path is not undefined == false)",
    "Operator_is_not_undefined_2": "$value(NullValue is not undefined)",
    "Operator_is_not_undefined_3": "$value(Double1 is not undefined)",
    "Operator_is_not_undefined_5": "$value(Companies.Select(c => c.Employees).First() is not undefined)",
    "Operator_is_not_undefined_6": "$value(Companies.Select(c => c.Employees).First(e => e.Age > 200) is not undefined == false)"
  }
}

The result (i.e., an instance of JsonQL.Compilation.ICompilationResult) is serialized to a Result.json file below.

Note

For brevity, the serialized result includes only serialized evaluated Examples.json and does not include parent JSON files in JsonQL.Compilation.ICompilationResult.CompiledJsonFiles

Click to expand the result in instance of JsonQL.Compilation.ICompilationResult serialized into Result.json

{
  "CompiledJsonFiles":[
    {
      "TextIdentifier": "Examples",
      "CompiledParsedValue":
      {
        "Operator_is_null": {
          "Comment_Operator_is_null_1":  "(invalid.path is null) evaluates to false. For invalid path check use 'is undefined' operator",
          "Operator_is_null_1":  true,
          "Operator_is_null_2":  true,
          "Operator_is_null_3":  true,
          "Operator_is_null_5":  true,
          "Comment_Operator_is_null_6_1":  "Even though the query below results in no employee being selected. The value is not null",
          "Comment_Operator_is_null_6_2":  "'is null' succeeds if there is JsonPath with null value.",
          "Comment_Operator_is_null_6_3":  "'Use 'is undefined' instead to check if query resulted in any value",
          "Operator_is_null_6":  true
        },
        "Operator_is_not_null": {
          "Comment_Operator_is_not_null_1":  "(invalid.path is not null) evaluates to true.",
          "Operator_is_not_null_1":  true,
          "Operator_is_not_null_2":  true,
          "Operator_is_not_null_3":  true,
          "Operator_is_not_null_5":  true,
          "Operator_is_not_null_6":  true
        },
        "Operator_is_undefined": {
          "Comment_Operator_is_undefined_1":  "(invalid.path is undefined) evaluates to true.",
          "Operator_is_undefined_1":  true,
          "Operator_is_undefined_2":  true,
          "Operator_is_undefined_3":  true,
          "Operator_is_undefined_5":  true,
          "Operator_is_undefined_6":  true
        },
        "Operator_is_ not_undefined": {
          "Comment_Operator_is_not_undefined_1":  "(invalid.path is not undefined) evaluates to false.",
          "Operator_is_not_undefined_1":  true,
          "Operator_is_not_undefined_2":  true,
          "Operator_is_not_undefined_3":  true,
          "Operator_is_not_undefined_5":  true,
          "Operator_is_not_undefined_6":  true
        }
      }
    }
  ],
  "CompilationErrors":
  {
    "$type": "System.Collections.Generic.List`1[[JsonQL.Compilation.ICompilationErrorItem, JsonQL]], System.Private.CoreLib",
    "$values": []
  }
}

The code snippet shows how the JSON file Examples.json was parsed using JsonQL.Compilation.IJsonCompiler

// Set the value of jsonCompiler to an instance of JsonQL.Compilation.IJsonCompiler here.
// The value of JsonQL.Compilation.JsonCompiler is normally created by Dependency Injection container
// and it is normally configured as a singleton.
JsonQL.Compilation.IJsonCompiler jsonCompiler = null!;

var sharedExamplesFolderPath = new []
{
    "DocFiles", "MutatingJsonFiles", "Examples"
};

var dataJsonTextData = new JsonTextData("Data", this.LoadExampleJsonFile("Data.json"));

var companiesJsonTextData = new JsonTextData("Companies",
    LoadJsonFileHelpers.LoadJsonFile("Companies.json", sharedExamplesFolderPath), dataJsonTextData);

var result = jsonCompiler.Compile(new JsonTextData("Examples",
    this.LoadExampleJsonFile("Examples.json"), companiesJsonTextData));