/**
* Render markup for an image tag in smarty
*
* The {img} smarty function is the recommended way to load images in templates from asset or public directories.
* In addition to automatically resolving URLs, it can also handle server-side resizing and a few other nifty features.
*
* #### Image Types & Animations
*
* As of Core 3.3.0, image types are preserved, so if a .jpg is requested, an image/jpeg is returned.
* This changed from the previous behaviour where all images were converted to a PNG.
*
* Supported image types are `.jp[e]g`, `.png`, and `.gif`.
*
* If an animated gif is resized, the server will attempt to preserve the animation on the resized image.
* This is done via imagemagick, (so that library needs to be present on the server in order for this trick to work).
*
* #### SEO Data
*
* As of Core 3.2.0, alt tags are automatically added to every image that does not have the alt attribute explicitly set.
* This alt name is pulled from the filename of the image, with automatic capitalization and '_' => (space) converting.
*
* #### Smarty Parameters
*
* * assign
* * string
* * Set to a string to assign that variable name instead of returning the output.
* * dimensions
* * Provide both width and height in pixels, along with special instructions
* * Structure is "widthxheight" with no spaces between the "x" and the two integers.
* * Special modes available are:
* * Carat "`^`" at the end of the string fits the smallest dimension instead of the largest.
* * Exclamation mark "`!`" at the end forces size regardless of aspect ratio.
* * Greater than "`>`" at the end will only increase image sizes.
* * Less than "`<`" at the end will only decrease image sizes.
* * file
* * \Core\Filestore\File
* * File object passed in to display
* * Either "file" or "src" is required.
* * height
* * int
* * Maximum image height (in pixels).
* * If both width and height are provided, the image will be constrained to both without any distortion.
* * inline
* * int "1" or "0", (default "0")
* * New in Core 4.2.0
* * Request that the resized image be encoded as base64 and inserted inline in the markdown instead of returned as the URL.
* * placeholder
* * string
* * placeholder image if the requested image is blank or not found. Useful for optional fields that should still display something.
* * Current values: "building", "generic", "person", "person-tall", "person-wide", "photo"
* * src
* * string
* * Source filename to display. This can start with "assets" for an asset, or "public" for a public file.
* * Either "file" or "src" is required.
* * width
* * int
* * Maximum image width (in pixels).
* * If both width and height are provided, the image will be constrained to both without any distortion.
*
* Any other parameter is transparently sent to the resulting `<img/>` tag.
*
*
* #### Example Usage
*
* <pre>
* {img src="public/gallery/photo123.png" width="123" height="123" placeholder="photo" alt="My photo 123"}
* </pre>
*
* @param array $params Associative (and/or indexed) array of smarty parameters passed in from the template
* @param Smarty $smarty Parent Smarty template object
*
* @return string
* @throws SmartyException
*/
function smarty_function_img($params, $smarty){
// Key/value array of attributes for the resulting HTML.
$attributes = array();
if(isset($params['file'])){
$f = $params['file'];
if(!$f instanceof \Core\Filestore\File){
throw new SmartyException('{img} tag expects a \Core\Filestore\File object for the "file" parameter.');
}
unset($params['file']);
}
elseif(isset($params['src'])){
$f = \Core\Filestore\Factory::File($params['src']);
unset($params['src']);
}
else{
$f = null;
}
// Some optional parameters, (and their defaults)
$assign = $width = $height = $dimensions = $inline = false;
$placeholder = $previewfile = null;
if(isset($params['assign'])){
$assign = $params['assign'];
unset($params['assign']);
}
if(isset($params['width'])){
$width = $params['width'];
unset($params['width']);
}
if(isset($params['height'])){
$height = $params['height'];
unset($params['height']);
}
if(isset($params['dimensions'])){
$dimensions = $params['dimensions'];
$width = preg_replace('#[^0-9]?([0-9]*)x.*#', '$1', $dimensions);
$height = preg_replace('#.*x([0-9]*)[^0-9]?#', '$1', $dimensions);
unset($params['dimensions']);
}
if(isset($params['placeholder'])){
$placeholder = $params['placeholder'];
unset($params['placeholder']);
}
if(isset($params['inline'])){
$inline = ($params['inline'] == '1');
unset($params['inline']);
}
if($dimensions){
// Passing in dimensions raw will allow the user more control over the size of the images.
$d = $dimensions;
}
else{
// If one is provided but not the other, just make them the same.
if($width && !$height) $height = $width;
if($height && !$width) $width = $height;
$d = ($width && $height) ? $width . 'x' . $height : false;
}
// If the file doesn't exist and a placeholder was provided, use the appropriate placeholder image!
if(!($f && $f->exists() && $f->isImage()) && $placeholder){
// Try that!
$f = \Core\Filestore\Factory::File('assets/images/placeholders/' . $placeholder . '.png');
}
if(!$f){
throw new SmartyException('{img} tag requires either "src", "file", or a "placeholder" parameter.');
}
// Do the rest of the attributes that the user sent in (if there are any)
foreach($params as $k => $v){
$attributes[$k] = $v;
}
if($f instanceof Core\Filestore\Backends\FileRemote){
// Erm... Give the original URL with the dimension requests.
$attributes['src'] = $f->getURL();
if($width) $attributes['width'] = $width;
if($height) $attributes['height'] = $height;
}
else{
// Try to lookup the preview file.
// if it exists, then YAY... I can return that direct resource.
// otherwise, I should check and see if the file is larger than a set filesize.
// if it is, then I want to return a link to a controller to render that file instead of rendering the file from within the {img} tag.
//
// This is useful because any logic contained within this block will halt page execution!
// To improve the perception of performance, that can be offloaded to the browser requesting the <img/> contents.
$previewfile = $d ? $f->getQuickPreviewFile($d) : $f;
if(!$previewfile){
$attributes['src'] = '#';
$attributes['title'] = 'No preview files available!';
}
elseif($inline && $f->getFilesize() < 1048576*4){
// Overwrite the src attribute with the base64 contents.
// This can only happen after the preview file exists!
if(!$previewfile->exists()){
// Since quick ran, ensure that it's actually resized!
$previewfile = $f->getPreviewFile($d);
}
$attributes['src'] = 'data:' . $previewfile->getMimetype() . ';base64,' . base64_encode($previewfile->getContents());
}
elseif(!$previewfile->exists()){
// Ok, it doesn't exist... return a link to the controller to render this file.
$attributes['src'] = \Core\resolve_link('/file/preview') . '?f=' . $f->getFilenameHash() . '&d=' . $d;
}
else{
$attributes['src'] = $previewfile->getURL();
}
}
// All images need alt data!
if(!isset($attributes['alt'])){
$attributes['alt'] = $f->getTitle();
}
// Merge them back together in one string.
$html = '<img';
foreach($attributes as $k => $v) $html .= " $k=\"$v\"";
$html .= '/>';
// If the extended metadata was requested... look that up too!
if(isset($params['includemeta']) && $params['includemeta']){
$metahelper = new \Core\Filestore\FileMetaHelper($f);
$metacontent = $metahelper->getAsHTML();
if($metacontent){
$html = '<div class="image-metadata-wrapper">' . $html . $metacontent . '</div>';
}
}
return $assign ? $smarty->assign($assign, $html) : $html;
}
/**
* Utility to Core-ify a given HTML string.
*
* Will use a tokenizer to scan for <img /> tags and <a /> tags.
*
* @param $html
* @return string
*/
function parse_html($html){
// Counter for the current position of the tokenizer.
$x = 0;
// Set to the position of the current image
$imagestart = null;
// @todo a rel=nofollow tags for external/untrusted links
// This can make use of an external utility to allow the admin to set which links are allowed.
// @todo a tags that are absolutely resolved or have a core prefix such as core:///about-us or what not.
while($x < strlen($html)){
// Replace images with the optimized version.
if(substr($html, $x, 4) == '<img'){
$imagestart = $x;
$x+= 3;
continue;
}
$fullimagetag = null;
if($imagestart !== null && $html{$x} == '>'){
// This will equal the full image HTML tag, ie: <img src="blah"/>...
$fullimagetag = substr($html, $imagestart, $x-$imagestart+1);
}
elseif($imagestart !== null && substr($html, $x, 2) == '/>'){
// This will equal the full image HTML tag, ie: <img src="blah"/>...
$fullimagetag = substr($html, $imagestart, $x-$imagestart+2);
}
if($imagestart !== null && $fullimagetag){
// Convert it to a DOM element so I can process it.
$simple = new \SimpleXMLElement($fullimagetag);
$attributes = array();
foreach($simple->attributes() as $k => $v){
$attributes[$k] = (string)$v;
}
$file = \Core\Filestore\Factory::File($attributes['src']);
// All images need alt tags.
if(!isset($attributes['alt']) || $attributes['alt'] == ''){
// Since this is usually only used to render content and the images contained therein,
// and tinymce auto-adds a blank alt="" attribute,
// I can safely add the alt based on the file's rendered title.
$attributes['alt'] = $file->getTitle();
}
if(isset($attributes['width']) || isset($attributes['height'])){
if(isset($attributes['width']) && isset($attributes['height'])){
$dimension = $attributes['width'] . 'x' . $attributes['height'] . '!';
unset($attributes['width'], $attributes['height']);
}
elseif(isset($attributes['width'])){
$dimension = $attributes['width'];
unset($attributes['width']);
}
else{
$dimension = $attributes['height'];
unset($attributes['height']);
}
$attributes['src'] = $file->getPreviewURL($dimension);
}
// And rebuild.
$img = '<img';
foreach($attributes as $k => $v){
$img .= ' ' . $k . '="' . str_replace('"', '"', $v) . '"';
}
$img .= '/>';
$metahelper = new \Core\Filestore\FileMetaHelper($file);
$metacontent = $metahelper->getAsHTML();
if($metacontent){
$img = '<div class="image-metadata-wrapper">' . $img . $metacontent . '</div>';
}
// Figure out the offset for X. I'll need to modify this after I merge it in.
$x += strlen($img) - strlen($fullimagetag);
// Split this string back in.
$html = substr_replace($html, $img, $imagestart, strlen($fullimagetag));
// Reset...
$imagestart = null;
}
$x++;
}
//var_dump($html);
return $html;
}
