OnTopic-Library/OnTopic/TopicFactory.cs at master · OnTopicCMS/OnTopic-Library · GitHub

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/*==============================================================================================================================

| Author Ignia, LLC

| Client Ignia, LLC

| Project Topics Library

\=============================================================================================================================*/

using System.Text.RegularExpressions;

using OnTopic.Collections.Specialized;

using OnTopic.Lookup;

using OnTopic.Metadata;

namespace OnTopic {

/*============================================================================================================================

| CLASS: TOPIC FACTORY

\---------------------------------------------------------------------------------------------------------------------------*/

/// <summary>

/// A static class for centralizing logic for creating strongly-typed <see cref="Topic"/> instances based on their content

/// type.

/// </summary>

public static class TopicFactory {

/*==========================================================================================================================

| PROPERTY: TYPE LOOKUP SERVICE

\-------------------------------------------------------------------------------------------------------------------------*/

/// <summary>

/// Establishes static variables for the <see cref="TopicFactory"/>.

/// </summary>

public static ITypeLookupService TypeLookupService { get; set; } = new DynamicTopicLookupService();

/*==========================================================================================================================

| METHOD: CREATE

\-------------------------------------------------------------------------------------------------------------------------*/

/// <summary>

/// Factory method for creating new strongly-typed instances of the topics class, assuming a strongly-typed subclass is

/// available. Used for cases where a <see cref="Topic"/> is being deserialized from an existing instance, as indicated

/// by the <paramref name="id"/> parameter.

/// </summary>

/// <remarks>

/// When the <paramref name="id"/> parameter is set the <see cref="TrackedRecord{T}.IsDirty"/> property is set to

/// <c>false</c> on <see cref="Topic.Key"/> as well as on <see cref="Topic.ContentType"/>, since it is assumed these are

/// being set to the same values currently used in the persistence store.

/// </remarks>

/// <param name="key">A string representing the key for the new topic instance.</param>

/// <param name="contentType">A string representing the key of the target content type.</param>

/// <param name="parent">Optional topic to set as the new topic's parent.</param>

/// <param name="id">The unique identifier assigned by the data store for an existing topic.</param>

/// <exception cref="ArgumentException">

/// Thrown when the class representing the content type is found, but doesn't derive from <see cref="Topic"/>.

/// </exception>

/// <returns>A strongly-typed instance of the <see cref="Topic"/> class based on the target content type.</returns>

public static Topic Create(string key, string contentType, Topic? parent = null, int id = -1) {

/*------------------------------------------------------------------------------------------------------------------------

| Validate input

\-----------------------------------------------------------------------------------------------------------------------*/

Contract.Requires<ArgumentNullException>(!String.IsNullOrWhiteSpace(key), nameof(key));

Contract.Requires<ArgumentNullException>(!String.IsNullOrWhiteSpace(contentType), nameof(contentType));

ValidateKey(key);

ValidateKey(contentType);

/*------------------------------------------------------------------------------------------------------------------------

| Determine target type

\-----------------------------------------------------------------------------------------------------------------------*/

var targetType = TypeLookupService.Lookup(contentType);

//Fallback to generic AttributeDescriptor if the specific attribute descriptor cannot be found

if (targetType is null && contentType.EndsWith("AttributeDescriptor", StringComparison.OrdinalIgnoreCase)) {

targetType = typeof(AttributeDescriptor);

}

if (targetType is null) {

targetType = typeof(Topic);

}

/*------------------------------------------------------------------------------------------------------------------------

| Identify the appropriate topic

\---------------------------------------------------------------------------------------------------------------------*/

return (Topic)Activator.CreateInstance(targetType, key, contentType, parent, id)!;

}

/// <inheritdoc cref="Create(String, String, Topic?, Int32)"/>

[ExcludeFromCodeCoverage]

[Obsolete("The 'id' parameter has been moved to the end of the parameter list.", true)]

public static Topic Create(string key, string contentType, int id, Topic? parent) =>

throw new NotImplementedException();

/// <inheritdoc cref="Create(String, String, Topic?, Int32)"/>

public static Topic Create(string key, string contentType, int id) =>

Create(key, contentType, null, id);

/*==========================================================================================================================

| METHOD: VALIDATE KEY

\-------------------------------------------------------------------------------------------------------------------------*/

/// <summary>

/// Validates the format of a key used for an individual topic.

/// </summary>

/// <remarks>

/// Topic keys may be exposed as, for example, virtual routes and, thus, should not contain spaces, slashes, question

/// marks or other symbols reserved for URLs. This method is marked static so that it can also be used by the static Code

/// Contract Checker.

/// </remarks>

/// <param name="topicKey">The topic key that should be validated.</param>

/// <param name="isOptional">Allows the topicKey to be optional (i.e., a null reference).</param>

public static void ValidateKey(string? topicKey, bool isOptional = false) {

Contract.Requires<InvalidKeyException>(isOptional || !String.IsNullOrEmpty(topicKey));

Contract.Requires<InvalidKeyException>(

String.IsNullOrEmpty(topicKey) || Regex.IsMatch(topicKey, @"^[a-zA-Z0-9\.\-_]+$"),

"Key names should only contain letters, numbers, hyphens, periods, and/or underscores."

);

}

} //Class

} //Namespace

OnTopic-Library/OnTopic/TopicFactory.cs at master · OnTopicCMS/OnTopic-Library · GitHub

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