set title to be filename stripping characters

Thanks for the positive feedback and for your question. As you found in the earlier topic you referenced, MLA has a number of “data sources” you can use to compose new values for fields like the Title. However, to “clean up” the values or to make more complex changes requires a bit of PHP code, easily placed in your theme’s functions.php file or a small custom plugin. In fact, similar requests have come before. This earlier topic is very close to yours:

Quick question on replacing string(s) in image metadata

Another topic describes a very small custom plugin that creates Title values containing an active link based on an IPTC value:

EXIF/Template Value editing

The code in the second example is somewhat smaller than the first. For your specific application, it can be even simpler. Here is the complete source code of a custom plugin for your application:

<?php
/**
 * Replaces the Title by a cleaned up version of the file name.
 *
 * @package MLA File Name Mapping Hooks Example
 * @version 1.00
 */

/*
Plugin Name: MLA File Name Mapping Hooks Example
Plugin URI: https://fairtradejudaica.org/media-library-assistant-a-wordpress-plugin/
Description: Replace Title with hyperlink, for Jeff Dean.
Author: David Lingren
Version: 1.01
Author URI: https://fairtradejudaica.org/our-story/staff/

Copyright 2014 - 2016 David Lingren

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You can get a copy of the GNU General Public License by writing to the
	Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110, USA
*/

/**
 * Class MLA File Name Mapping Hooks Example hooks one of the filters provided by the IPTC/EXIF and Custom Field mapping features
 *
 * Call it anything you want, but give it an unlikely and hopefully unique name. Hiding enerything
 * else inside a class means this is the only name you have to worry about.
 *
 * @package MLA File Name Mapping Hooks Example
 * @since 1.00
 */
class MLAFileNameMappingHooksExample {
	/**
	 * Initialization function, similar to __construct()
	 *
	 * Installs filters and actions that handle the MLA hooks for uploading and mapping.
	 *
	 * @since 1.00
	 *
	 * @return	void
	 */
	public static function initialize() {
		/*
		 * The filters are only useful in the admin section; exit if in the "front-end" posts/pages.
		 */
		if ( ! is_admin() )
			return;

		/*
		 * add_filter parameters:
		 * $tag - name of the hook you're filtering; defined by [mla_gallery]
		 * $function_to_add - function to be called when [mla_gallery] applies the filter
		 * $priority - default 10; lower runs earlier, higher runs later
		 * $accepted_args - number of arguments your function accepts
		 * Comment out the filters you don't need; save them for future use
		 */
		add_filter( 'mla_mapping_updates', 'MLAFileNameMappingHooksExample::mla_mapping_updates_filter', 10, 5 );
	}

	/**
	 * MLA Mapping Updates Filter
	 *
	 * This filter is called AFTER all mapping rules are applied.
	 * You can add, change or remove updates for the attachment's
	 * standard fields, taxonomies and/or custom fields.
	 *
	 * @since 1.00
	 *
	 * @param	array	updates for the attachment's standard fields, taxonomies and/or custom fields
	 * @param	integer post ID to be evaluated
	 * @param	string 	category/scope to evaluate against: custom_field_mapping or single_attachment_mapping
	 * @param	array 	mapping rules
	 * @param	array 	attachment_metadata, default NULL
	 *
	 * @return	array	updated attachment's updates
	 */
	public static function mla_mapping_updates_filter( $updates, $post_id, $category, $settings, $attachment_metadata ) {
		/*
		 * We are only concerned with Standard Field mapping
		 */
		if ( ! in_array( $category, array( 'iptc_exif_mapping', 'iptc_exif_standard_mapping' ) ) ) {
			return $updates;
		}

		/*
		 * If $updates[ 'post_title' ] is set, some mapping rule
		 * has been set up, so we respect the result. If not,
		 * use whatever the current Title value is.
		 */
		if ( isset( $updates[ 'post_title' ] ) ) {
			$old_value = $updates[ 'post_title' ];
		} else {
			$post = get_post( $post_id );
			$old_value = $post->post_title;
		}

		/*
		 * Derive the new Title from the file name (without the extension).
		 * You can use MLAOptions::mla_get_data_source() to get anything available.
		 */
		$my_setting = array(
			'data_source' => 'template',
			'meta_name' => '([+name_only+])',
			'option' => 'raw'
		);
		$name_only = trim( MLAOptions::mla_get_data_source( $post_id, 'single_attachment_mapping', $my_setting, NULL ) );

		if ( ! empty( $name_only ) ) {
			$new_title = str_replace( array( '-', '_' ), ' ', $name_only );
			if ( $old_value != $new_title ) {
				$updates[ 'post_title' ] = $new_title;
			}
		}

		return $updates;
	} // mla_mapping_updates_filter
} //MLAFileNameMappingHooksExample

/*
 * Install the filters at an early opportunity
 */
add_action('init', 'MLAFileNameMappingHooksExample::initialize');
?>

If you put the above code in a file called, for example, mla-file-name-mapping-hooks-example.php, install the file in your pluging directory and activate it, you can re-map your existing items and apply the cleanup to new items as well.

I am marking this topic resolved, but please update it if you have problems or further questions regarding the above solution. Thanks for your interest in the plugin.

Wow, thanks for your great reply David!

according to your topic link I came up with this as I do not want an extra plugin if not really neccesary:

function mla_mapping_updates_filter( $updates, $post_id, $category, $settings, $attachment_metadata ) {
    /*
   * If $updates[ 'post_title' ] is set, some mapping rule
   * has been set up, so we respect the result. If not,
   * use whatever the current Title value is.
   */
  if ( isset( $updates[ 'post_title' ] ) ) {
      $old_value = $updates[ 'post_title' ];
  } else {
      $post = get_post( $post_id );
      $old_value = $post->post_title;
  }

  /*
   * Clean up the Title value. If the cleanup has changed the value,
   * put the new value in the $updates array.
   */
  $new_title = str_replace( array( '-', '_', '.' ), ' ', $old_value );
  if ( $old_value != $new_title ) {
      $updates[ 'post_title' ] = $new_title;
  }

  // Only replace ALT Text if Image Metadata is present
  $old_value = get_metadata( 'post', $post_id, '_wp_attachment_metadata', true );
  if ( ! empty( $old_value ) ) {
      // Find the current ALT Text value
      if ( isset( $updates[ 'image_alt' ] ) ) {
          $old_value = $updates[ 'image_alt' ];
      } else {
          $old_value = get_metadata( 'post', $post_id, '_wp_attachment_image_alt', true );
      }

      // Replace the ALT Text value with the clean Title
      if ( $old_value != $new_title ) {
          $updates[ 'image_alt' ] = $new_title;
      }
  }

  return $updates;
}

I put in in my functions.php
it’s not working unfortunately, do you know why?
I have set Title, ALT Text and Caption to template:([+file_name+]) with priority EXIF.

obviously Im missing something but I have no clue yet.

another question, what exactly do you mean by // Only replace ALT Text if Image Metadata is present, does that mean it only replaces the ALT if it is populated?

To be clear< I would like Title, ALT and Caption all replaced with the cleaned up filename when mapping.

Thanks David!

Thanks for your update with the additional information and the adapted code. Here are some updates and a new version of the code that should be helpful.

First, with this code you don’t have to set up mapping rules for your Title, ALT Text and Caption fields. That’s why I used mla_get_data_source in my example to get the file name (without the extension). I’ve put that back in the code below.

Second, the Caption value is stored in the post_excerpt database field. I have added code to update that value.

Third, WordPress stores the ALT Text value in a different way, in the postmeta table as if it was a custom field. WordPress does not store a value at all for non-image types like PDF documents. That’s why the code tests for “image metadata” and only stores an ALT Text value if the test succeeds.

Finally, the mla_mapping_updates_filter function will not be called at all unless you register it with WordPress. You need to find a place in your functions.php file to run this statement:

add_filter( 'mla_mapping_updates', 'mla_mapping_updates_filter', 10, 5 );

In the example plugin, registration is done in the initialize function, and there is a bit of code at the bottom of the plugin that runs the initialize function as WordPress loads the plugin:

/*
 * Install the filters at an early opportunity
 */
add_action('init', 'MLAFileNameMappingHooksExample::initialize');

Your functions.php file may already have code similar to this. If not, you will have to add the initialize function and the add_action code that activates it. Be sure to change initialize to something unique like mla_initialize_filter and then change the add_action parameter to match it.

Let me know if that makes sense, or if you still have problems/questions. Here is the updated code:

function mla_mapping_updates_filter( $updates, $post_id, $category, $settings, $attachment_metadata ) {
  /*
   * Derive the new Title from the file name (without the extension).
   * Clean up the file name for use in the Title, Caption and ALT Text fields.
   */
  $my_setting = array(
    'data_source' => 'template',
    'meta_name' => '([+name_only+])',
    'option' => 'raw'
  );
  $name_only = trim( MLAOptions::mla_get_data_source( $post_id, 'single_attachment_mapping', $my_setting, NULL ) );
  $new_value = str_replace( array( '-', '_', '.' ), ' ', $name_only );

  /*
   * If $updates[ 'post_title' ], etc. is set, some mapping rule has been set up, so we respect the result.
   * If not, use whatever the current value is.
   */
  if ( isset( $updates[ 'post_title' ] ) ) {
      $old_title = $updates[ 'post_title' ];
  } else {
      $post = get_post( $post_id );
      $old_title = $post->post_title;
  }

  /*
   * If the cleanup has changed the value,
   * put the new value in the $updates array.
   */
  if ( $old_title != $new_value ) {
      $updates[ 'post_title' ] = $new_value;
  }

  if ( isset( $updates[ 'post_excerpt' ] ) ) {
      $old_caption = $updates[ 'post_excerpt' ];
  } else {
      $post = get_post( $post_id );
      $old_caption = $post->post_excerpt;
  }

  if ( $old_caption != $new_value ) {
      $updates[ 'post_excerpt' ] = $new_value;
  }

  // Only replace ALT Text if Image Metadata is present
  $old_metadata = get_metadata( 'post', $post_id, '_wp_attachment_metadata', true );
  if ( ! empty( $old_metadata ) ) {
      // Find the current ALT Text value
      if ( isset( $updates[ 'image_alt' ] ) ) {
          $old_alt = $updates[ 'image_alt' ];
      } else {
          $old_alt = get_metadata( 'post', $post_id, '_wp_attachment_image_alt', true );
      }

      // Replace the ALT Text value with the clean file name
      if ( $old_alt != $new_value ) {
          $updates[ 'image_alt' ] = $new_value;
      }
  }

  return $updates;
}

Thanks for the extensive answer David! really appreciate it.

I lost you at the last part with the initialize part.
I now have:
add_filter( 'mla_mapping_updates', 'mla_mapping_updates_filter', 10, 5 );
with next:
add_action('init', 'mla_mapping_updates_filter'); (this is possibly wrong, but I thought this is the way to connect it to the function.

and the function you posted in your last reply underneath it:

function mla_mapping_updates_filter( $updates, $post_id, $category, $settings, $attachment_metadata ) {
//left this part out for overview reasons
}

all in the functions.php
is this correct?

Thanks for taking the time to try and follow the instructions in my last post. The initialization process makes sense if you’re a PHP programmer, but it’s hard to describe and follow on its own.

After some further thought I realize that a better approach is to copy the entire PHP class from the example plugin along with the add_action code that follows it. If you just add this code to your functions.php file, replacing your previous version, it should work for you:

class MLAFileNameMappingHooksExample {
    public static function initialize() {
        /*
         * The filters are only useful in the admin section; exit if in the "front-end" posts/pages.
         */
        if ( ! is_admin() )
            return;

        add_filter( 'mla_mapping_updates', 'MLAFileNameMappingHooksExample::mla_mapping_updates_filter', 10, 5 );
    }

    /**
     * MLA Mapping Updates Filter
     *
     * This filter is called AFTER all mapping rules are applied.
     * You can add, change or remove updates for the attachment's
     * standard fields, taxonomies and/or custom fields.
     *
     * @since 1.00
     *
     * @param    array    updates for the attachment's standard fields, taxonomies and/or custom fields
     * @param    integer post ID to be evaluated
     * @param    string     category/scope to evaluate against: custom_field_mapping or single_attachment_mapping
     * @param    array     mapping rules
     * @param    array     attachment_metadata, default NULL
     *
     * @return    array    updated attachment's updates
     */
    public static function mla_mapping_updates_filter( $updates, $post_id, $category, $settings, $attachment_metadata ) {
        /*
         * Derive the new Title from the file name (without the extension).
         * Clean up the file name for use in the Title, Caption and ALT Text fields.
         */
        $my_setting = array(
            'data_source' => 'template',
            'meta_name' => '([+name_only+])',
            'option' => 'raw'
        );
        $name_only = trim( MLAOptions::mla_get_data_source( $post_id, 'single_attachment_mapping', $my_setting, NULL ) );
        $new_value = str_replace( array( '-', '_', '.' ), ' ', $name_only );

        /*
         * If $updates[ 'post_title' ], etc. is set, some mapping rule has been set up, so we respect the result.
         * If not, use whatever the current value is.
         */
        if ( isset( $updates[ 'post_title' ] ) ) {
            $old_title = $updates[ 'post_title' ];
        } else {
            $post = get_post( $post_id );
            $old_title = $post->post_title;
        }

        /*
         * If the cleanup has changed the value,
         * put the new value in the $updates array.
         */
        if ( $old_title != $new_value ) {
            $updates[ 'post_title' ] = $new_value;
        }

        if ( isset( $updates[ 'post_excerpt' ] ) ) {
            $old_caption = $updates[ 'post_excerpt' ];
        } else {
            $post = get_post( $post_id );
            $old_caption = $post->post_excerpt;
        }

        if ( $old_caption != $new_value ) {
            $updates[ 'post_excerpt' ] = $new_value;
        }

        // Only replace ALT Text if Image Metadata is present
        $old_metadata = get_metadata( 'post', $post_id, '_wp_attachment_metadata', true );
        if ( ! empty( $old_metadata ) ) {
            // Find the current ALT Text value
            if ( isset( $updates[ 'image_alt' ] ) ) {
                $old_alt = $updates[ 'image_alt' ];
            } else {
                $old_alt = get_metadata( 'post', $post_id, '_wp_attachment_image_alt', true );
            }

            // Replace the ALT Text value with the clean file name
            if ( $old_alt != $new_value ) {
                $updates[ 'image_alt' ] = $new_value;
            }
        }

        return $updates;
    } // mla_mapping_updates_filter
} //MLAFileNameMappingHooksExample

/*
 * Install the filters at an early opportunity
 */
add_action('init', 'MLAFileNameMappingHooksExample::initialize');

The add_action statement at the end sets up a call to the initialize function, which in turn calls the add_filter function at an appropriate time. Putting all the code inside a PHP Class lets you use function names like initialize without the risk of overwriting someone else’s code.

Thanks for sticking with this evolving topic.

You sir, are awesome!
It’s awesome how much effort a plugin author can put into helping the users.
this is working, I will donate to you David! thanks!
Can I donate to you personally?

Thanks for your update with the good news, and for your donation offer. Positive feedback, reviews and donations to our Fair Trade work are great motivators to keep working on the plugin and supporting its users. Fair Trade Judaica is a very personal (just my spouse and I) effort and working on the FTJ web site gave me the original idea for MLA.