Title: Plugin guidance wanted
Last modified: August 18, 2016

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# Plugin guidance wanted

 *  [cptdondo](https://wordpress.org/support/users/cptdondo/)
 * (@cptdondo)
 * [21 years ago](https://wordpress.org/support/topic/plugin-guidance-wanted/)
 * I’m in the process of writing my very first plugin for WP. You can see a rough
   example at [http://www.seiner.com/blog/Travels/](http://www.seiner.com/blog/Travels/)
   with the ‘Image Test Post’. It pops up a window to show a larger image, along
   with some other functionality. Mostly, it provides a way to show a thumbnail,
   a snapshot (640×480 in my case) and the full resolution (~2000×1000 px) for download.
   I threw in the email and the print buttons just to learn javascript…
 * I would like to add previous / next buttons. The way I read the docs, I can either
   use an action or a filter. An action would modify the post before it went into
   the database, whereas a filter modifies the post on the fly as it is sent to 
   the client. Do I have that right?
 * Which is the preferred method? If I use action on save_post, I would need to 
   read in the entire text of the post, parse out the images, and rewrite the href
   tags to include the appropriate tags for previous and next images. The advantage
   of this is that the post is only modified once, but it mucks about with the original
   post, which I am not entirely comfortable with…. Also, I have to recognize tags
   that I’ve already modified….
 * OTOH, a filter would be executed every time the post is requested, so CPU usage
   would be high…. But it leaves the original post untouched.
 * So…. Any guidance? Any other suggestions? I have not found any other image viewer
   plugins that implement prev/next buttons. Anything I am missing? It seems that
   a filter would be easier to implement, if less efficient…
 * Thanks,
 * –Yan

The topic ‘Plugin guidance wanted’ is closed to new replies.

 * 0 replies
 * 1 participant
 * Last reply from: [cptdondo](https://wordpress.org/support/users/cptdondo/)
 * Last activity: [21 years ago](https://wordpress.org/support/topic/plugin-guidance-wanted/)
 * Status: not resolved

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