1. 1 Information Management DIG 3563 – Lecture 8 Content Management Systems: Plugins for Wordpress J. Michael Moshell University of Central Florida Original image* by Moshell et al. Imagery is fromWikimedia except where marked with *.

2. -2 - About Wordpress Modules Plugins There are LOTS of them Their quality varies widely - Maturity (length of service; number of users) - Continuing support - Experience of the builder How to find out? Read the posting and forums!

3. -3 - Some Random Plugin Visits Petfinder Listing Relies on the Petfinder.com API (So you don’t have to build your own back-end). Petfinder.com can host an entire animal-welfare website. Petfinder Listing allows YOUR site to get data from a Petfinder.com – hosted website.

4. -4 - Gpawisconsin.org

5. -5 - Some Random Plugin Visits Buddypress Actually a COLLECTION of plugins to support social networking http://wordpress.org/extend/plugins/buddypress/ Example: http://helloecoliving.com/community/

6. -6 - How is it built? See Source!

7. -7 - How is it built? See Source!

8. -8 - Examples: BuddyMobile “Mobile BuddyPress theme optimized for... iPhone, iPod touch. Will also work on Android & some Blackberry devices.” For BuddyPress 1.5 only.

9. -9 - Examples: BuddyPress Media “Production grade” social media hosting “Drag and Drop” photos, audio, video between Facebook, Flickr, YouTube... ecommerce capabilities 2.7 million users, 16,000 sites.

10. -10 - Beer Ratings Requires a RateBeer API Key Better not say too much about this one; somebody might do it for a term project and we've had TOO MANY like this!

11. -11 - WP Survey and Quiz Tool Promising topic; many people need this Maintenance via GitHub BUT: Daunting feedback.

12. -12 - SS Quiz Downloads: 5,319 Apparently a Russian product I decide to get it and try it.

13. -13 - SS Quiz Downloads: 5,319 Apparently a Russian product I decide to get it and try it. 1) Download and unzip 2) Move into wordpress/wp-content/plugins 3) In the Plugin menu, activate

14. -14 - SS Quiz Downloads: 5,319 Apparently a Russian product I decide to get it and try it. 1) Download and unzip 2) Move into wordpress/wp-content/plugins 3) In the Plugin menu, activate 4) A new row appears in the Dashboard

15. -15 - SS Quiz “To insert quiz into page, use short code [ssquiz id=‘#’]. So I create a page and call it ‘Mikwiz’, insert [ssquiz id=‘1’]. Quiz appeared. I took it.

16. -16 - SS Quiz: Control Panel

17. -17 - SS Quiz: Control Panel Issues: (1) Why were questions 3, 4 radio buttons? while 1,2,5 were textboxes? (2) Is the data stored anywhere? Answers: Exploring, I found:

18. -18 - SS Quiz: Scores Stores the number of correct answers; no details

19. -19 - SS Quiz: Template Augmented HTML, with %TITLE% etc.

20. -20 - SS Quiz: Template How do I set “Title” and other variables? Experimenting with the user interface, I observe the phrase “Let’s start the quiz “%TITLE%”! On the quiz page, I see:

21. -21 - SS Quiz: Template Likewise, I observe:

22. -22 - SS Quiz: Template SO I conclude that these “variables” correspond to built-in features of the SS Quiz Plugin: TITLE DESCRIPTION QUESTIONS (number of questions entered)

23. -23 - SS Quiz: Template And likewise, PERCENT TOTAL

24. -24 - SS Quiz: We Played a bit Experiment with creation of a Quiz and the use of the Question Editor

25. -25 - SS Quiz: We Play a bit Experiment with creation of a Quiz and the use of the Question Editor Identify one or more shortcomings of the Plugin:

26. -26 - SS Quiz: We Play a bit Experiment with creation of a Quiz and the use of the Question Editor Identify one or more shortcomings of the Plugin: no UNDO. I delete a question, it’s gone no actual answer storage. I can’t diagnose...

27. -27 - Time to Build our Own Plugin. I seek a Tutorial. http://codex.wordpress.org/Writing_a_Plugin I start a log (word document) to remember what I do.

28. -28 - Step 1: Trivially modify existing code Hello Dolly Go to Plugins menu, activate the plugin. Small lines of text appear in upper right corner of the Admin screen.

29. -29 - Step 1: Trivially modify existing code Understand the Header Comment It’s NOT ignored by the system. It’s essential!

30. -30 - Step 1: Trivially modify existing code Make a copy of hello.php, call it hello2.php Look at plugins menu again. Wierd, huh?

31. -31 - Step 1: Trivially modify existing code Modify hello2 just enough to recognize it. Change its name to dolly2 change text to refer to ‘Herman’ Note and fix the add_action( ) function. KEY QUESTION: WHAT ARE ‘actions’?

32. -32 - Step 1: Trivially modify existing code Learn about ‘actions’. http://codex.wordpress.org/Plugin_API/Action_Refe rence NOTE: You are not required to program in this course. But you are required to understand key concepts, and action is one of those.

33. -33 - Step 1: Trivially modify existing code An Action in Wordpress is called an event in other languages. As Wordpress runs, it will check its action lists for functions that should be called, at various times. Each plugin can add functions to those lists.

34. -34 -

35. -35 -...and many more...

36. -36 - Step 1: Trivially modify existing code There's a plugin that looks "Suspiciously" like a Hello-World (starter kit) example

37. -37 - Step 1: Trivially modify existing code The action in this “Hello Dolly” story is called admin_notices. 'admin_notices', which apparently has to do with the top row of the admin screen.

38. -38 - Step 1: Trivially modify existing code So, I add my OWN action to see what happens.

39. -39 - Step 1: Trivially modify existing code So, I add my OWN action to see what happens. I edited hello.php as above. And the result...

40. -40 - Step 2: Make something more interesting I wanted to put something into the main data area, where PAGES appear. It took me an hour of exploring to discover an example. Cut to the chase... here’s what I found.

41. -41 - Step 2: Make something more interesting I wanted to put something into the main data area, where PAGES appear. It took me an hour of exploring to discover an example. Cut to the chase... here’s what I found.

42. -42 - Step 2: Make something more interesting Example: A ‘filter’ to replace all the “ ” tags in a page with ‘ ’ tags. How was that done? With REGULAR EXPRESSIONS!

43. -43 - Step 2: Make something more interesting I wanted to actually inject some copy into a page. So I added an operator to replace a tag ‘JMMtrigger’ with the text.

44. -44 - Step 2: Make something more interesting

45. -45 - And I had to find an Action to use. The example code showed me this: A ‘filter’ is an action that will take in the content of a page, do stuff to it, and then send it on to the screen. So this filter will add the JMMexchange stuff.

46. -46 - JMMexchange will do two things: 1) Replace H1 with H3 tags, and 2) replace the word JMMtrigger with the data provided by my function.

47. -47 - Then I needed a page to contain the stuff. Edit-view:

48. -48 - Then I needed a page to contain the stuff. HTML-view

49. -49 - AND the result on my front page.

50. -50 - Things to understand about Plugin-making: 1)Making Plugins requires PHP skills 2)What is an Action 3)What is a Filter 4)What is the relationship between the code in the Plugin, and the text of a page? How is the plugin’s activity triggered? How can it modify the text of a page?

51. -51 - Things to understand about Plugins: 1) Their quality and complexity varies WIDELY 2) They seldom do exactly what you want 3)You can modify ‘em, but keep a clean copy. AND the MORAL: Invest the effort to find a module* that actually does what you need (or, as close as possible.) (*: Plugin, in Wordpress-speak!)