Publish a New Article

The current user (as identified by an injected authorisation class) can create and persist a new Prolog::Core::Article.

To use this, instantiate a new Prolog::UseCases::PublishNewArticle class, passing a :repository and an :authoriser as parameters to the initialiser, and then call the instance's #call method, passing in a Hash or equivalent containing the necessary/desired attributes.

The :authoriser passed to #initialize must respond to

1. the :guest? message, returning true or false; and
2. the :current_user message, returning a string with the current logged-in user name (or a null equivalent such as "Guest User" when no user is logged in).

The :repository passed to #initialize must respond to the :save message, accepting a Prolog::Core::Article instance as a parameter and returning the passed-in parameter on success. (The failure semantics for #save have not yet been defined).

The Hash of parameters passed into #call are as follows:

Key	Required?	Description of value
:title	Yes	A trimmed string (see Note 1) containing the title of the new Article
:author_name	Yes	A trimmed string containing the user name of the Member creating the new Article
:current_user	Yes	A string containing the user name of the Member presently logged in, or a null equivalent such as "Guest User" when no user is logged in.
:body	See Note 2	If specified, a string containing the body text of the new Article
:image_url	See Note 2	If specified, a string containing a valid URL for an image to be associated with the Article
:keywords	No	An array of strings to be used as keywords for the new Article

Notes

Note 1: A "trimmed string" is a string which

• is not empty;
• is not completely blank (containing only spaces or other similar whitespace);
• has no leading or trailing whitespace;
• has no more than one space between words in its text.

Note 2: A valid Article must have valid :body text, a valid :image_url, or both. For a :body to be valid, it must be a non-zero-length, non-blank string. A valid :image_url attribute is an http- or https-protocol URL that is valid in form (whether the image is actually retrievable is not checked).