Question

I’d like to embed an image or a div tag with a fixed width in the admin panel in order to set a minimum width. Something like this,

<div style="width:1000px; height:0px; border:0px;"></div>

I could not find a proper hook for it. This page http://codex.wordpress.org/Plugin_API/Action_Reference lists available hooks and I tried some of them including wp_before_admin_bar_render, wp_after_admin_bar_render. But it is too late to embed an image because #wpcontent is already loaded and rendered. I also tried admin_head but it is too early to embed an image; the width does not take any effect. I need to put the image before the div element of #wpcontent. I guess it’s after rendering the menu on the left.

Is it possible?

Specifying a width for #wpcontent directly in the stylesheet wasn’t successful in different WordPress versions. So I’m looking for alternatives. Thanks for your info.

Answer 1

It seems the problem was not the timing of when it is inserted but the style of the div tag. Since the purpose of this is to create a minimum width in the admin panel, the border:0px does not create a solid element. Therefore, the browser seems to ignore it.

Inserting this worked.

<div id="min-width" style="width:1000px; height:0px; border:1px; border-style:solid; border-color: rgba(0,0,0,0);"></div>

This is the sample plugin which demonstrates how to do it.

<?php
    /* Plugin Name: Sample Embed Image for Admin Page Width  */

    add_action('plugins_loaded', create_function('', 
        '$o = new AdminPageClass_EmbedImage("Sample Embed Image in Admin Panel"
                , "Sample Embed Image in Admin Panel"
                , "manage_options"
                , "sample_embed_image_in_admin_panel");
        '));

    class AdminPageClass_EmbedImage {

        function __construct($title, $menuname, $privilege, $pageslug) {
            $this->title = $title;
            $this->menuname = $menuname;
            $this->privilege = $privilege;
            $this->pageslug = $pageslug;
            add_action('admin_menu', array(&$this, 'admin_menu'));  
            add_action('wp_before_admin_bar_render', array(&$this, 'embed_image')); // inserts it between #wpcontent and #wpadminbar
            // add_action('in_admin_header', array(&$this, 'embed_image')); // inserts it between #wpadminbar and #wp-body which is after #wpcontent
            // add_action('network_admin_notices', array(&$this, 'embed_image')); // no insertion
            // add_action('user_admin_notices', array(&$this, 'embed_image')); // no insertion
            // add_action('admin_notices', array(&$this, 'embed_image')); // inserts it after #screen-meta inside #wpbody-content which is inside #wp-content
            // add_action('all_admin_notices', array(&$this, 'embed_image')); // same as 'admin_notices'
        }
        function admin_menu() {
            add_options_page($this->title, $this->menuname, $this->privilege, $this->pageslug, array(&$this, 'admin_page'));
        }
        function embed_image() {
            ?>
            <div id="min-width" style="width:1000px; height:0px; border:1px; border-style:solid; border-color: rgba(0,0,0,0);"></div>
            <?
        }
        function admin_page() {
            // $this->embed_image();
            ?>
            <div class="wrap">
                <h1>Hi there</h1>
                <?php // $this->embed_image(); ?>
                <p>Hello World!</p>
            </div>
            <?php
        }
    }