IComparisonExpressionEvaluator

IComparisonExpressionEvaluator interface

Cuando se implementa, permite anular la evaluación de expresiones de comparación predeterminadas para elFieldIf yFieldCompare campos.

public interface IComparisonExpressionEvaluator

Métodos

NombreDescripción
Evaluate(Field, ComparisonExpression)Evalúa la expresión de comparación.

Ejemplos

Muestra cómo implementar la evaluación personalizada para los campos SI y COMPARAR.

public void ConditionEvaluationExtensionPoint(string fieldCode, sbyte comparisonResult, string comparisonError,
    string expectedResult)
{
    const string left = "\"left expression\"";
    const string @operator = "<>";
    const string right = "\"right expression\"";

    DocumentBuilder builder = new DocumentBuilder();

    // Códigos de campo que utilizamos en este ejemplo:
    // 1. " SI {0} {1} {2} \"argumento verdadero\" \"argumento falso\" ".
    // 2. " COMPARAR {0} {1} {2} ".
    Field field = builder.InsertField(string.Format(fieldCode, left, @operator, right), null);

    // Si "comparisonResult" no está definido, creamos "ComparisonEvaluationResult" con una cadena, en lugar de un valor booleano.
    ComparisonEvaluationResult result = comparisonResult != -1
        ? new ComparisonEvaluationResult(comparisonResult == 1)
        : comparisonError != null ? new ComparisonEvaluationResult(comparisonError) : null;

    ComparisonExpressionEvaluator evaluator = new ComparisonExpressionEvaluator(result);
    builder.Document.FieldOptions.ComparisonExpressionEvaluator = evaluator;

    builder.Document.UpdateFields();

    Assert.AreEqual(expectedResult, field.Result);
    evaluator.AssertInvocationsCount(1).AssertInvocationArguments(0, left, @operator, right);
}

/// <summary>
/// Evaluación de expresiones de comparación para FieldIf y FieldCompare.
/// </summary>
private class ComparisonExpressionEvaluator : IComparisonExpressionEvaluator
{
    public ComparisonExpressionEvaluator(ComparisonEvaluationResult result)
    {
        mResult = result;
        if (mResult != null)
        {
            Console.WriteLine(mResult.ErrorMessage);
            Console.WriteLine(mResult.Result);
        }
    }

    public ComparisonEvaluationResult Evaluate(Field field, ComparisonExpression expression)
    {
        mInvocations.Add(new[]
        {
            expression.LeftExpression,
            expression.ComparisonOperator,
            expression.RightExpression
        });

        return mResult;
    }

    public ComparisonExpressionEvaluator AssertInvocationsCount(int expected)
    {
        Assert.AreEqual(expected, mInvocations.Count);
        return this;
    }

    public ComparisonExpressionEvaluator AssertInvocationArguments(
        int invocationIndex,
        string expectedLeftExpression,
        string expectedComparisonOperator,
        string expectedRightExpression)
    {
        string[] arguments = mInvocations[invocationIndex];

        Assert.AreEqual(expectedLeftExpression, arguments[0]);
        Assert.AreEqual(expectedComparisonOperator, arguments[1]);
        Assert.AreEqual(expectedRightExpression, arguments[2]);

        return this;
    }

    private readonly ComparisonEvaluationResult mResult;
    private readonly List<string[]> mInvocations = new List<string[]>();
}

Ver también

IBibliographyStylesProvider Interface IFieldDatabaseProvider Interface