Remove fields on media uploader for custom page type – not working for “From Computer” or “From Url” tabs?

Version 1

Deals with filtering based on Post ID

*From Computer* tab

we need to retrieve the $attachment_parent_id:

add_filter('attachment_fields_to_edit', 'wpse_53600_remove_media_upload_fields', 10000, 2);
function wpse_53600_remove_media_upload_fields( $form_fields, $post ) {
    $our_page_id = 4;
    $post_id = !empty( $_GET['post_id'] ) ? (int) $_GET['post_id'] : 0;
    $attachment_parent_id = !empty($post->post_parent) ? $post->post_parent : 0;

    if( $post_id == $our_page_id || $attachment_parent_id == $our_page_id ){
        // Please, check VERSION 2 for full code
    }
    return $form_fields;
}

*From URL* tab

looks like another approach is necessary:

add_filter('type_url_form_media', 'wpse_53600_remove_from_url_fields', 10, 1);
function wpse_53600_remove_from_url_fields($html) {
    $our_page_id = 4;
    $post_id = !empty( $_GET['post_id'] ) ? (int) $_GET['post_id'] : 0;

    if( $post_id != $our_page_id)
        return $html;

    // Used to hide the unwanted table rows
    $display_none="style="display:none"";

    $html="";// Please, check VERSION 2 for full code

    return $html;
}



Version 2

Deals with filtering based on Post Type
/*
 * Remove extra fields from Media Upload tabs based on the Post Type
 * In this example, it is a CPT named 'movie', but it could be 'post' or 'page'
 *
 * http://wordpress.stackexchange.com/q/53600/12615
 */

add_filter('type_url_form_media', 'wpse_53600_remove_from_url_fields', 10, 1);
add_filter('attachment_fields_to_edit', 'wpse_53600_remove_media_upload_fields', 10000, 2);

/* FILTERS THE 'FROM COMPUTER' TAB */
function wpse_53600_remove_from_url_fields($html) {

    $post_id = !empty( $_GET['post_id'] ) ? (int) $_GET['post_id'] : 0;
    $post_type = get_post_type($post_id);

    if( 'movie' != $post_type)
        return $html;

    // Used to hide the unwanted table rows
    $display_none="style="display:none"";

    $html = <<<HTML
     <p class="media-types">
        <label><input type="radio" name="media_type" value="image" id="image-only" checked='checked' /> Image</label> &nbsp; &nbsp; <label><input type="radio" name="media_type" value="generic" id="not-image" /> Audio, Video, or Other File</label>
    </p> 
    <table class="describe ">
        <tbody> 
            <tr> <th valign="top" scope="row" class="label" style="width:130px;"> <span class="alignleft"><label for="src">URL</label></span> <span class="alignright"><abbr id="status_img" title="required" class="required">*</abbr></span> </th> <td class="field"><input id="src" name="src" value="" type="text" aria-required="true" onblur="addExtImage.getImageData()" /></td> </tr>
            <tr> <th valign="top" scope="row" class="label"> <span class="alignleft"><label for="title">Title</label></span> <span class="alignright"><abbr title="required" class="required">*</abbr></span> </th> <td class="field"><input id="title" name="title" value="" type="text" aria-required="true" /></td> </tr>
            <tr class="not-image" {$display_none}><td></td><td><p class="help">Link text, e.g. &#8220;Ransom Demands (PDF)&#8221;</p></td></tr>
            <tr class="image-only" {$display_none}> <th valign="top" scope="row" class="label"> <span class="alignleft"><label for="alt">Alternate Text</label></span> </th> <td class="field"><input id="alt" name="alt" value="" type="text" aria-required="true" /> <p class="help">Alt text for the image, e.g. &#8220;The Mona Lisa&#8221;</p></td> </tr>
            <tr class="image-only" {$display_none}> <th valign="top" scope="row" class="label"> <span class="alignleft"><label for="caption">Image Caption</label></span> </th> <td class="field"><input id="caption" name="caption" value="" type="text" /></td> </tr>
            <tr class="align image-only" {$display_none}> <th valign="top" scope="row" class="label"><p><label for="align">Alignment</label></p></th> <td class="field"> <input name="align" id="align-none" value="none" onclick="addExtImage.align='align'+this.value" type="radio" checked="checked" /> <label for="align-none" class="align image-align-none-label">None</label> <input name="align" id="align-left" value="left" onclick="addExtImage.align='align'+this.value" type="radio" /> <label for="align-left" class="align image-align-left-label">Left</label> <input name="align" id="align-center" value="center" onclick="addExtImage.align='align'+this.value" type="radio" /> <label for="align-center" class="align image-align-center-label">Center</label> <input name="align" id="align-right" value="right" onclick="addExtImage.align='align'+this.value" type="radio" /> <label for="align-right" class="align image-align-right-label">Right</label> </td> </tr>
            <tr class="image-only" {$display_none}> <th valign="top" scope="row" class="label"> <span class="alignleft"><label for="url">Link Image To:</label></span> </th> <td class="field"><input id="url" name="url" value="" type="text" /><br /> <button type="button" class="button" value="" onclick="document.forms[0].url.value=null">None</button> <button type="button" class="button" value="" onclick="document.forms[0].url.value=document.forms[0].src.value">Link to image</button> <p class="help">Enter a link URL or click above for presets.</p></td> </tr>
            <tr class="image-only"> <td></td> <td> <input type="button" class="button" id="go_button" style="color:#bbb;" onclick="addExtImage.insert()" value="Insert into Post" /> </td> </tr>
            <tr class="not-image"> <td></td> <td> <input type="submit" name="insertonlybutton" id="insertonlybutton" class="button" value="Insert into Post" /> </td> </tr>
        </tbody>
    </table>
HTML;

    return $html;
}

/* FILTERS THE REST OF THE TABS */
function wpse_53600_remove_media_upload_fields( $form_fields, $post ) {

    $post_id = !empty( $_GET['post_id'] ) ? (int) $_GET['post_id'] : 0;
    $post_type = get_post_type($post_id);

    $attachment_parent_id = !empty($post->post_parent) ? $post->post_parent : 0;
    $attachment_post_type = get_post_type($attachment_parent_id);

    /* 
     * This conditional will also filter the attachments in the Library tab that fall under the 'movie' CPT
     * Use the following to filter the Library tab: 
     *
     * $library_tab = ( isset($_GET['tab']) && 'library' == $_GET['tab']) ? true : false;
     *
     */ 
    if( 'movie' == $post_type || 'movie' == $attachment_post_type ){
        // remove unnecessary fields
        unset( $form_fields['image-size'] );
        unset( $form_fields['post_excerpt'] );
        unset( $form_fields['post_content'] );
        unset( $form_fields['url'] );
        unset( $form_fields['image_url'] );
        unset( $form_fields['align'] );
    }

    return $form_fields;
}