Decision trees will be a plugin which allows a user to create one or more branched (dendritic) decision trees from the WordPress admin area. A decision tree will consist of two or more nodes which each explain a question or item which requires a decision. Each node will have a number of one way paths from it to other nodes, I am referring to these as "answers".

This diagram from Wikipedia illustrates the kind of decision trees this plugin will handle. Note the simple branching structure, and that all nodes only link to their own child nodes, and there is no "doubling back" or "linking across". I hope this will keep a good level of simplicity, and help users to maintain a coherent mental model of each tree.

The plugin will register a CPT called "Decision Trees".

Editing

Required elements of a node:

• A title
• At least one answer

Initially we will just require multiple choice answers, which could be implemented as an array of links (most probably), or an array of radio buttons (I'm not sure why Smart Answers implements the selection mechanism as a form, it seems less crawlable… but perhaps they're not bothered). I'd like to have it so that the selection mechanism for the answers can be extended using another plugin.

Here's a mockup showing how I think of the selection meta box with just the basic multiple choice answers available:

In the model above, when you add an answer you are simultaneously adding a new child node and defining the answer text. If no title is provided, the answer text should be used for the title; however it should be possible for the text of the answer leading to a node to be separate from the title of that node.

I think re-parenting nodes will not be necessary.

Here's mockup showing how the selection meta box might work with some additional selection mechanisms enabled:

As an admin user, it would be useful to be able to navigate an entire decision tree while it is in draft, before it's published. This would require filtering permalinks to make them preview compatible.

It would be useful to be able to publish an entire decision tree in one action, rather than having to set the post_status on each node in turn.

Display

The answer links (or other selection mechanism) should be appended using the_content filter, and should have lots of lovely classes and IDs for CSS.

If no answer text has been provided, then the title of the child nodes should be used.

There should be no archive view for the Decision Trees CPT.

Currently you cannot delete an individual answer from the editing screen. We need to decide on the desired behaviour.

When you delete an answer, should it also delete the answer node? If so, should this be recursive so all its answers and nodes are deleted too?

cc simonwheatley

When you remove a node, it triggers a PHP error:

NOTICE: TRYING TO GET PROPERTY OF NON-OBJECT IN /WP-CONTENT/PLUGINS/DECISION-TREES-MASTER/DECISION-TREES.PHP ON LINE 690

Thank you,

Sorry for my obvious ignorance.
I want to style the output pages different than the default.
In wordpress I can use the custom css in customizer to add code to all or some pages.
For example, if I want to make certain text bold or a different font or justification or color.
But I don't know the names of the objects?
If someone would write a couple styling examples and list the names of the containers or objects? then less technical users could style the output. Like me =)

Hi,
Can we link the same node for 2 differents trees ?
Thank you

Just installed the plugin and when adding an answer to a node got a fatal error: Call to undefined function get_called_class() in /kunden/399092_47441/webseiten/wordpress/wp-content/plugins/decision-trees-master/class-answers-simple.php on line 25

Any ideas how to solve that?

Thanks in advance

Chris

...also, duplicates are being created in the visualize area, not linked to previous answer.

This plugin needs a 3.6 style icon. Possibly worth waiting to see how the icons pan out. /cc @imsimond

TODO: Write this up.

This seems to be the only plugin which works right out of the box. Thank you guys!
I read the other issues regarding deleting answers. But what if i want to add a new answer in between an existent tree? do i have to delete the other following answer first and start from that new answer now? whats the best way?

kind regards
nic

Add some area of the screen which shows the display of the answer which led to the current node, so that it's possible to see the context of how you arrived where you are.