pip-services3-commons-node
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Portable abstractions and patterns for Pip.Services in Node.js
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JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
/** @module reflect */
/** @hidden */
var _ = require('lodash');
/**
* Helper class to perform property introspection and dynamic reading and writing.
*
* This class has symmetric implementation across all languages supported
* by Pip.Services toolkit and used to support dynamic data processing.
*
* Because all languages have different casing and case sensitivity rules,
* this PropertyReflector treats all property names as case insensitive.
*
* ### Example ###
*
* let myObj = new MyObject();
*
* let properties = PropertyReflector.getPropertyNames();
* PropertyReflector.hasProperty(myObj, "myProperty");
* let value = PropertyReflector.getProperty(myObj, "myProperty");
* PropertyReflector.setProperty(myObj, "myProperty", 123);
*/
var PropertyReflector = /** @class */ (function () {
function PropertyReflector() {
}
PropertyReflector.matchField = function (fieldName, fieldValue, expectedName) {
if (_.isFunction(fieldValue))
return false;
if (_.startsWith(fieldName, '_'))
return false;
if (expectedName == null)
return true;
return fieldName.toLowerCase() == expectedName;
};
/**
* Checks if object has a property with specified name..
*
* @param obj an object to introspect.
* @param name a name of the property to check.
* @returns true if the object has the property and false if it doesn't.
*/
PropertyReflector.hasProperty = function (obj, name) {
if (obj == null)
throw new Error("Object cannot be null");
if (name == null)
throw new Error("Property name cannot be null");
name = name.toLowerCase();
for (var field in obj) {
var fieldValue = obj[field];
if (PropertyReflector.matchField(field, fieldValue, name))
return true;
}
return false;
};
/**
* Gets value of object property specified by its name.
*
* @param obj an object to read property from.
* @param name a name of the property to get.
* @returns the property value or null if property doesn't exist or introspection failed.
*/
PropertyReflector.getProperty = function (obj, name) {
if (obj == null)
throw new Error("Object cannot be null");
if (name == null)
throw new Error("Property name cannot be null");
name = name.toLowerCase();
for (var field in obj) {
var fieldValue = obj[field];
try {
if (PropertyReflector.matchField(field, fieldValue, name))
return fieldValue;
}
catch (ex) {
// Ignore exceptions
}
}
return null;
};
/**
* Gets names of all properties implemented in specified object.
*
* @param obj an objec to introspect.
* @returns a list with property names.
*/
PropertyReflector.getPropertyNames = function (obj) {
var properties = [];
for (var field in obj) {
var fieldValue = obj[field];
if (PropertyReflector.matchField(field, fieldValue, null))
properties.push(field);
}
return properties;
};
/**
* Get values of all properties in specified object
* and returns them as a map.
*
* @param obj an object to get properties from.
* @returns a map, containing the names of the object's properties and their values.
*/
PropertyReflector.getProperties = function (obj) {
var map = {};
for (var field in obj) {
var fieldValue = obj[field];
try {
if (PropertyReflector.matchField(field, fieldValue, null))
map[field] = fieldValue;
}
catch (ex) {
// Ignore exception
}
}
return map;
};
/**
* Sets value of object property specified by its name.
*
* If the property does not exist or introspection fails
* this method doesn't do anything and doesn't any throw errors.
*
* @param obj an object to write property to.
* @param name a name of the property to set.
* @param value a new value for the property to set.
*/
PropertyReflector.setProperty = function (obj, name, value) {
if (obj == null)
throw new Error("Object cannot be null");
if (name == null)
throw new Error("Property name cannot be null");
var expectedName = name.toLowerCase();
for (var field in obj) {
var fieldValue = obj[field];
try {
if (PropertyReflector.matchField(field, fieldValue, expectedName)) {
obj[field] = value;
return;
}
}
catch (ex) {
// Ignore exception
}
}
// If no existing properties found set it directly
obj[name] = value;
};
/**
* Sets values of some (all) object properties.
*
* If some properties do not exist or introspection fails
* they are just silently skipped and no errors thrown.
*
* @param obj an object to write properties to.
* @param values a map, containing property names and their values.
*
* @see [[setProperty]]
*/
PropertyReflector.setProperties = function (obj, values) {
if (values == null)
return;
for (var field in values) {
var fieldValue = values[field];
PropertyReflector.setProperty(obj, field, fieldValue);
}
};
return PropertyReflector;
}());
exports.PropertyReflector = PropertyReflector;
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