ValidateAsNumberFunction.java :  » GWT » itemscript » org » itemscript » schema » Java Open Source

package org.itemscript.schema;

import java.util.List;

import org.itemscript.core.JsonSystem;
import org.itemscript.core.Params;
import org.itemscript.core.exceptions.ItemscriptError;
import org.itemscript.core.values.JsonObject;
import org.itemscript.core.values.JsonValue;
import org.itemscript.template.Template;
import org.itemscript.template.TemplateExec;
import org.itemscript.template.expression.Expression;
import org.itemscript.template.expression.Function;
import org.itemscript.template.expression.FunctionBase;
import org.itemscript.template.expression.FunctionFactory;
import org.itemscript.template.expression.FunctionFoundry;

/**
 * Represents a more specific validate Function used to parse user input that is provided in a String
 * into a Number. Only used to validate values against the Number or Integer Types.
 * 
 * @author Eileen Bai
 */
public class ValidateAsNumberFunction extends FunctionBase {
  
  /**
   * Adds the "validateAsNumber" function into the FunctionFoundry.
   * Therefore ensuring that this function is only intialized when it is needed.
   */
  public static void init() {
    FunctionFoundry.put("validateAsNumber", new FunctionFactory() {
      //@Override
      public Function create(JsonSystem system, List<Expression> args) {
        return new ValidateAsNumberFunction(system, args);
      }
    });
  }
  
  Schema schema;
  
  /**
   * Constructs a new ValidateAsNumberFunction.
   * 
   * @param system
   * @param args - the arguments provided to "validateAsNumber."
   */
    public ValidateAsNumberFunction(JsonSystem system, List<Expression> args) {
        super(system, args);
        schema = new Schema(system);
    }

    //@Override
    public JsonValue execute(TemplateExec templateExec, JsonValue context, JsonValue value) {
    if (value == null) {
      return Template.setErrorMessage(onError(ItemscriptError.internalError(this,
          "execute.validateAsNumber.value.was.null",
            value + "")));
    }
    else if (!(value.isString() || value.isNumber())) {
      throw ItemscriptError.internalError(this,
          "execute.validateAsNumber.value.was.not.a.string.or.number", value + "");
    }
    else if (args().size() != 1) {
      throw ItemscriptError.internalError(this,
          "execute.validateAsNumber.only.one.arg.allowed");
    }
    else {
      JsonValue typeValue = args().get(0).interpret(templateExec, context);
      Type type;
      try {
        type = schema.resolve(typeValue);
      } catch (ItemscriptError e) {
        return Template.setErrorMessage(onError(e));
      }
      if (!(type.isNumber() || type.isInteger())) {
        throw ItemscriptError.internalError(this,
            "execute.validateAsNumber.type.was.not.number.or.integer", value+"");
      }
      if (value.isString()) {
        double val;
        try {
          val = Double.parseDouble(value.stringValue());
        } catch (NumberFormatException e) {
          return Template.setErrorMessage(onError(
            ItemscriptError.internalError(this,
              "execute.validateAsNumber.value.asNumber.could.not.be.parsed.into.double",
                value+""))
                .p("value", value+""));
        }
        value = system().createNumber(val);
      }
      try {
        schema.validate(type, value);
        return onSuccess();
      } catch (ItemscriptError e) {
        return Template.setErrorMessage(onError(e));
      }
    }
    }
    
  private JsonObject onError(Throwable e) {
    JsonObject errorObject = system().createObject();
    errorObject.put("valid", false);
    Params params = (Params) ((ItemscriptError) e).params();
    errorObject.put("specified", params.get("specified"));
    errorObject.put("input", params.get("input"));
    errorObject.put("value", params.get("value"));
    errorObject.put("key", params.get("key"));
    if (e instanceof ItemscriptError) {
      errorObject.put("errorMessage", ((ItemscriptError) e).key());
    }
    return errorObject;
  }

  private JsonObject onSuccess() {
    JsonObject successObject = system().createObject();
    successObject.put("valid", true);
    successObject.put("message", "validated successfully");
    return successObject;
  }
}