• Feb 16, 2017

During the run-up to Connect next week, I turned my gaze back to my indefinite-term project of reforming this blog in Darwino.

When last I left it publicly, I had set up replication between a copy of the database and a Darwino app. After that post, I did a bit of tinkering in the direction of building a (J)Ruby on Rails front-end for it, next to the "j2ee" project. That side effort may bear fruit in time (as I recall, I got the embedded web app serving default pages, but didn't implement any blog-specific logic), but for now I decided to go for the "just get something running" route.

For that, the most expedient route was to write an Angular app using Darwino's stock document REST APIs. The (now unavailable) Bootstrap theme I use here came packaged with an Angular 1.x example and the Darwino demo apps are largely Angular 1.x as well, so most of the work was adapting what was there.

Unrelated to the front end, there was one change I realized I needed to make. In a fit of "psh, it's an XPages app; I don't need that old crap!", I structured the comments in the blog such that they're related to their post via a "PostID" field with the post UNID, not as actual response documents. While that would work just fine in the new form, this is a good opportunity to clean up the data a bit. Since I haven't (at least not yet) implemented a specific method in the DSL to say "this field is the real parent ID", I modified the Darwino adapter script to set the parent ID on outgoing data after normal conversion:

form('Comment') {
	field 'CommentID'
	field 'PostID'
	field '$$Creator', flags:[NAMES, MULTIPLE]
	field 'AuthorName'
	field 'AuthorEmailAddress'
	field 'AuthorURL'
	field 'Remote_Addr'
	field 'HTTP_User_Agent'
	field 'HTTP_Referer'
	field 'Posted', type:DATETIME
	field 'Body', type:RICHTEXT
  
	// Set the parent ID from the "PostID" field
  	events postConvertDominoToDarwino: { jsonHolder ->
      	jsonHolder.jsonObject.put("_parentid", jsonHolder.jsonObject.get("postid"))
  	}
}

The jsonHolder is a process object that contains the converted JSON to be sent to Darwino as well as a collection of the document's attachments and inline images. So, by setting the special "_parentid" field before the result is sent to the destination database, that value is used as the parent ID reference in the Darwino DB.

The other non-Angular addition I made was to add Gravatar support. This is an area where I'm currently doing it via a one-off utility class in the XPages app that spits out Gravatar images in an EL-compatible way. However, Darwino has a more idiomatic route: its built-in user directory/authentication system is extensible in a couple of ways, and one of those ways is to layer additional data providers on top of the primary directory.

For development purposes, my "directory" is just a static list of users specified in the darwino-beans.xml file, while it will presumably eventually point to my Domino server via LDAP to maintain consistent access. The basic static user bean looks like this:

<bean type="darwino/userdir" name="static" class="com.darwino.config.user.UserDirStatic" alias="demo,default">
	<property name="allowUnknownUsers">true</property>
	<list name="providers">
		<bean class="com.darwino.social.gravatar.GravatarUserProvider">
			<property name="imageSize">128</property>
		</bean>
	</list>
	<list name="users">
		<bean class=".User">
			<property name="dn">cn=Jesse,o=darwino</property>
			<property name="cn">Jesse</property>
			<property name="uid">jesse</property>
			<property name="email">jesse@darwino.com</property>
			<property name="password">secrets!</property>
			<list name="roles">
				<value>admin</value>
			</list>
			<list name="groups">
				<value>darwino</value>
			</list>
		</bean>
	</list>
</bean>

(please don't tell anyone my super-secret password)

The full syntax for Darwino beans is its own subject, but this instantiates a directory using the UserDirStatic class with a couple names - the "default" at the end means it'll be picked up by the stock configuration of a new app. The users are specified as instances of a nested class User with LDAP-like properties.

Separate from the specifics of the static user list, though, are the first two child elements: one tells the app that this directory should be consulted further even when a user doesn't exist in it, and the second instantiates a Gravatar user provider (which is in Darwino core). This user provider in turn tries to determine the user's email address - if the address is provided by the underlying directory, it uses that; otherwise, it tries the DN. These fallback behaviors come into play with comments: those users definitely wouldn't exist in the directory, but they DO have the email addresses entered during posting.

With this configuration in place, I can make image references like this:

<img src="$darwino-social/users/users/cn%3Djesse%2Co%3Ddarwino/content/photo" />

That runs through Darwino's stock social service to provide whatever image it can find from the provider - which in this case is a proxied-in Gravatar image.

So all that leaves now is the implementation of the front end. However, since this post is long enough and the code is currently an embarrassing mess, I'm going to punt on that for now and save it for later.

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