WordPress has a function called wp_is_mobile. It does very simple User Agent checking, which isn’t very reliable. There are a lot of user agents out there and they can easily be falsified. There is no guarantee that a browser representing itself as some user agent actually is that user agent. You can do more complicated … Read more
wp_is_mobile() does not really solve your problem completely. To be honest here, there is no logic in WordPress to achieve what you want First of all, wp_is_mobile() only checks for mobile devices. Tablets are excluded from this Window sizes are determined on browser side, not server side, so there are no way for php to … Read more
The only directory a theme or a plugin should write to is the uploads directory. That is the only directory with guaranteed write access (besides the server’s temporary directory). Anything else is wrong and might not work. There is no practical difference between both, except one: the upload directory may be on another (sub) domain … Read more
add_image_size does change the actual size of the image file. What I hava tried: function odevice_image_sizes() { add_image_size( ‘iphone-size’, 300, 100, true );//OF course the dimensions are not correct… add_image_size( ‘tablet-size’, 600, 300, true ); } function show_odevice_at_img_select($sizes) { $sizes[‘iphone-size’] = __( ‘Image size for iphone’ ); $sizes[‘tablet-size’] = __( ‘image size for tablet’ ); … Read more
I haven’t tested your code, but I recently spent a few hours hacking something together to solve the same issue — making background images set via the WordPress customizer load responsively. Feel free to use / modify the code below to your needs, and send any questions my way. I’m not a PHP expert by … Read more
I completed the task with fitvids.js by using the plugin FitVids for WordPress. Chris Coyier describes the integration with WordPress in his screencast Integrating FitVids.js into WordPress (on YouTube). My custom field name is video_url. I used the following code in my template: <?php if (!((get_post_meta($post->ID, ‘video_url’, TRUE))==”)) { echo wp_oembed_get( get_post_meta($post->ID, “video_url”, true) ); … Read more
The width=100% parameter is not valid in the video shortcode. It must be a number, in pixels, or omitted entirely. If it is omitted, then the code will use the $content_width global from the theme to define the width of the containing DIV. For more info on Content Width, see here: http://codex.wordpress.org/Content_Width
Following our exchange in the comments I’ve reread your question and have a pretty straightforward answer: It looks like it’s working fine. You are worried about the sizes attribute in your second example, but it’s the srcset attribute that you should look at and it is showing all of your image sizes: <img src=”http://xxx.dev/wp-content/uploads/Delft_IMG_6275-e1453192498922.jpg” class=”attachment-full … Read more
You shouldn’t. srcset is used for when you want to optimise the quality for different devices by serving different sizes of the same image. If you want to serve different crops, you should be using the picture element instead. For example, if the intention of your image sizes is to serve a ‘small’ version to … Read more
The answer is to use WP’s responsive images, customising the sizes attribute to suit your use case. Reading between the lines, I’m assuming here that you are using a responsive design approach to show the different layouts at different widths. The easiest way is to start by making yourself a replacement template tag function for … Read more