String Interpolation ‘$’

• The string interpolation function ‘$’ allows injecting one or more JsonQL expressions inside a string JsonValue using a format of type “$([Json QL Expression as a parameter])”.

• JsonQL evaluates all the occurrences of “$()” in JSON string value, and replaces them with evaluated expressions.

• The JsonQL expressions used in ‘$’ function should evaluate to a string (e.g., string, numeric, date/time or boolean values).

Example

Note

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

Example.json below demonstrates using string interpolation function $.

{
  "TestArray": [ 1, 3, 7, 9, 11, 13 ],

  "Comment1": "We can have multiple occurrences of '$' functions in",
  "Comment2": "JSON, values below. Using one in each to make lines shorter",
  "Example1": "Sum(TestArray): $(Sum(TestArray.Where(x => x > 3)))",
  "Example2": "Average salary: $(Average(Companies.Select(c => c.Employees.Select(e => e.Salary))))."
}

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 Example.json and does not include parent JSON files in JsonQL.Compilation.ICompilationResult.CompiledJsonFiles

{
  "CompiledJsonFiles":[
    {
      "TextIdentifier": "Example",
      "CompiledParsedValue":
      {
        "TestArray": [
          1,
          3,
          7,
          9,
          11,
          13
        ],
        "Comment1":  "We can have multiple occurrences of '$' functions in",
        "Comment2":  "JSON, values below. Using one in each to make lines shorter",
        "Example1":  "Sum(TestArray): 40",
        "Example2":  "Average salary: 102356.75."
      }
    }
  ],
  "CompilationErrors":
  {
    "$type": "System.Collections.Generic.List`1[[JsonQL.Compilation.ICompilationErrorItem, JsonQL]], System.Private.CoreLib",
    "$values": []
  }
}

The code snippet shows how the JSON file Example.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 companiesJsonTextData = new JsonTextData("Companies",
    LoadJsonFileHelpers.LoadJsonFile("Companies.json", sharedExamplesFolderPath));

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