這篇文章主要介紹了使用PHP+JavaScript將HTML元素轉(zhuǎn)換為圖片的實例分享,文后結(jié)果的截圖只能體現(xiàn)出替換的字體,也不能說將靜態(tài)頁面轉(zhuǎn)為圖片可以加快加載,只是這種做法比較interesting XD需要的朋友可以參考下
1，準備要素
1）替換字體的js文件
js代碼：
function com_stewartspeak_replacement() {
/*
Dynamic Heading Generator
By Stewart Rosenberger
http://www.stewartspeak.com/headings/
This script searches through a web page for specific or general elements
and replaces them with dynamically generated images, in conjunction with
a server-side script.
*/
replaceSelector("h1","dynatext/heading.php",true);//前兩個參數(shù)需要修改
var testURL = "dynatext/loading.gif" ;//修改為對應的圖片路徑
var doNotPrintImages = false;
var printerCSS = "replacement-print.css";
var hideFlicker = false;
var hideFlickerCSS = "replacement-screen.css";
var hideFlickerTimeout = 100;//這里可以做相應的修改
/* ---------------------------------------------------------------------------
For basic usage, you should not need to edit anything below this comment.
If you need to further customize this script's abilities, make sure
you're familiar with Javascript. And grab a soda or something.
*/
var items;
var imageLoaded = false;
var documentLoaded = false;
function replaceSelector(selector,url,wordwrap)
{
if(typeof items == "undefined")
items = new Array();
items[items.length] = {selector: selector, url: url, wordwrap: wordwrap};
}
if(hideFlicker)
{
document.write('<link id="hide-flicker" rel="stylesheet" media="screen" href="' + hideFlickerCSS + '" />');
window.flickerCheck = function()
{
if(!imageLoaded)
setStyleSheetState('hide-flicker',false);
};
setTimeout('window.flickerCheck();',hideFlickerTimeout)
}
if(doNotPrintImages)
document.write('<link id="print-text" rel="stylesheet" media="print" href="' + printerCSS + '" />');
var test = new Image();
test.onload = function() { imageLoaded = true; if(documentLoaded) replacement(); };
test.src = testURL + "?date=" + (new Date()).getTime();
addLoadHandler(function(){ documentLoaded = true; if(imageLoaded) replacement(); });
function documentLoad()
{
documentLoaded = true;
if(imageLoaded)
replacement();
}
function replacement()
{
for(var i=0;i<items.length;i++)
{
var elements = getElementsBySelector(items[i].selector);
if(elements.length > 0) for(var j=0;j<elements.length;j++)
{
if(!elements[j])
continue ;
var text = extractText(elements[j]);
while(elements[j].hasChildNodes())
elements[j].removeChild(elements[j].firstChild);
var tokens = items[i].wordwrap ? text.split(' ') : [text] ;
for(var k=0;k<tokens.length;k++)
{
var url = items[i].url + "?text="+escape(tokens[k]+' ')+"&selector="+escape(items[i].selector);
var image = document.createElement("img");
image.className = "replacement";
image.alt = tokens[k] ;
image.src = url;
elements[j].appendChild(image);
}
if(doNotPrintImages)
{
var span = document.createElement("span");
span.style.display = 'none';
span.className = "print-text";
span.appendChild(document.createTextNode(text));
elements[j].appendChild(span);
}
}
}
if(hideFlicker)
setStyleSheetState('hide-flicker',false);
}
function addLoadHandler(handler)
{
if(window.addEventListener)
{
window.addEventListener("load",handler,false);
}
else if(window.attachEvent)
{
window.attachEvent("onload",handler);
}
else if(window.onload)
{
var oldHandler = window.onload;
window.onload = function piggyback()
{
oldHandler();
handler();
};
}
else
{
window.onload = handler;
}
}
function setStyleSheetState(id,enabled)
{
var sheet = document.getElementById(id);
if(sheet)
sheet.disabled = (!enabled);
}
function extractText(element)
{
if(typeof element == "string")
return element;
else if(typeof element == "undefined")
return element;
else if(element.innerText)
return element.innerText;
var text = "";
var kids = element.childNodes;
for(var i=0;i<kids.length;i++)
{
if(kids[i].nodeType == 1)
text += extractText(kids[i]);
else if(kids[i].nodeType == 3)
text += kids[i].nodeValue;
}
return text;
}
/*
Finds elements on page that match a given CSS selector rule. Some
complicated rules are not compatible.
Based on Simon Willison's excellent "getElementsBySelector" function.
Original code (with comments and description):
http://simon.incutio.com/archive/2003/03/25/getElementsBySelector
*/
function getElementsBySelector(selector)
{
var tokens = selector.split(' ');
var currentContext = new Array(document);
for(var i=0;i<tokens.length;i++)
{
token = tokens[i].replace(/^\s+/,'').replace(/\s+$/,'');
if(token.indexOf('#') > -1)
{
var bits = token.split('#');
var tagName = bits[0];
var id = bits[1];
var element = document.getElementById(id);
if(tagName && element.nodeName.toLowerCase() != tagName)
return new Array();
currentContext = new Array(element);
continue;
}
if(token.indexOf('.') > -1)
{
var bits = token.split('.');
var tagName = bits[0];
var className = bits[1];
if(!tagName)
tagName = '*';
var found = new Array;
var foundCount = 0;
for(var h=0;h<currentContext.length;h++)
{
var elements;
if(tagName == '*')
elements = currentContext[h].all ? currentContext[h].all : currentContext[h].getElementsByTagName('*');
else
elements = currentContext[h].getElementsByTagName(tagName);
for(var j=0;j<elements.length;j++)
found[foundCount++] = elements[j];
}
currentContext = new Array;
var currentContextIndex = 0;
for(var k=0;k<found.length;k++)
{
if(found[k].className && found[k].className.match(new RegExp('\\b'+className+'\\b')))
currentContext[currentContextIndex++] = found[k];
}
continue;
}
if(token.match(/^(\w*)\[(\w+)([=~\|\^\$\*]?)=?"?([^\]"]*)"?\]$/))
{
var tagName = RegExp.$1;
var attrName = RegExp.$2;
var attrOperator = RegExp.$3;
var attrValue = RegExp.$4;
if(!tagName)
tagName = '*';
var found = new Array;
var foundCount = 0;
for(var h=0;h<currentContext.length;h++)
{
var elements;
if(tagName == '*')
elements = currentContext[h].all ? currentContext[h].all : currentContext[h].getElementsByTagName('*');
else
elements = currentContext[h].getElementsByTagName(tagName);
for(var j=0;j<elements.length;j++)
found[foundCount++] = elements[j];
}
currentContext = new Array;
var currentContextIndex = 0;
var checkFunction;
switch(attrOperator)
{
case '=':
checkFunction = function(e) { return (e.getAttribute(attrName) == attrValue); };
break;
case '~':
checkFunction = function(e) { return (e.getAttribute(attrName).match(new RegExp('\\b'+attrValue+'\\b'))); };
break;
case '|':
checkFunction = function(e) { return (e.getAttribute(attrName).match(new RegExp('^'+attrValue+'-?'))); };
break;
case '^':
checkFunction = function(e) { return (e.getAttribute(attrName).indexOf(attrValue) == 0); };
break;
case '$':
checkFunction = function(e) { return (e.getAttribute(attrName).lastIndexOf(attrValue) == e.getAttribute(attrName).length - attrValue.length); };
break;
case '*':
checkFunction = function(e) { return (e.getAttribute(attrName).indexOf(attrValue) > -1); };
break;
default :
checkFunction = function(e) { return e.getAttribute(attrName); };
}
currentContext = new Array;
var currentContextIndex = 0;
for(var k=0;k<found.length;k++)
{
if(checkFunction(found[k]))
currentContext[currentContextIndex++] = found[k];
}
continue;
}
tagName = token;
var found = new Array;
var foundCount = 0;
for(var h=0;h<currentContext.length;h++)
{
var elements = currentContext[h].getElementsByTagName(tagName);
for(var j=0;j<elements.length; j++)
found[foundCount++] = elements[j];
}
currentContext = found;
}
return currentContext;
}
}// end of scope, execute code
if(document.createElement && document.getElementsByTagName && !navigator.userAgent.match(/opera\/?6/i))
com_stewartspeak_replacement();
2）生成圖片的php文件
<?php
/*
Dynamic Heading Generator
By Stewart Rosenberger
http://www.stewartspeak.com/headings/
This script generates PNG images of text, written in
the font/size that you specify. These PNG images are passed
back to the browser. Optionally, they can be cached for later use.
If a cached image is found, a new image will not be generated,
and the existing copy will be sent to the browser.
Additional documentation on PHP's image handling capabilities can
be found at http://www.php.net/image/
*/
$font_file = 'trebuc.ttf' ;//可以做相應的xiuga
$font_size = 23 ;//可以做相應的修改
$font_color = '#000000' ;
$background_color = '#ffffff' ;
$transparent_background = true ;
$cache_images = true ;
$cache_folder = 'cache' ;
/*
---------------------------------------------------------------------------
For basic usage, you should not need to edit anything below this comment.
If you need to further customize this script's abilities, make sure you
are familiar with PHP and its image handling capabilities.
---------------------------------------------------------------------------
*/
$mime_type = 'image/png' ;
$extension = '.png' ;
$send_buffer_size = 4096 ;
// check for GD support
if(!function_exists('ImageCreate'))
fatal_error('Error: Server does not support PHP image generation') ;
// clean up text
if(empty($_GET['text']))
fatal_error('Error: No text specified.') ;
$text = $_GET['text'] ;
if(get_magic_quotes_gpc())
$text = stripslashes($text) ;
$text = javascript_to_html($text) ;
// look for cached copy, send if it exists
$hash = md5(basename($font_file) . $font_size . $font_color .
$background_color . $transparent_background . $text) ;
$cache_filename = $cache_folder . '/' . $hash . $extension ;
if($cache_images && ($file = @fopen($cache_filename,'rb')))
{
header('Content-type: ' . $mime_type) ;
while(!feof($file))
print(($buffer = fread($file,$send_buffer_size))) ;
fclose($file) ;
exit ;
}
// check font availability
$font_found = is_readable($font_file) ;
if(!$font_found)
{
fatal_error('Error: The server is missing the specified font.') ;
}
// create image
$background_rgb = hex_to_rgb($background_color) ;
$font_rgb = hex_to_rgb($font_color) ;
$dip = get_dip($font_file,$font_size) ;
$box = @ImageTTFBBox($font_size,0,$font_file,$text) ;
$image = @ImageCreate(abs($box[2]-$box[0]),abs($box[5]-$dip)) ;
if(!$image || !$box)
{
fatal_error('Error: The server could not create this heading image.') ;
}
// allocate colors and draw text
$background_color = @ImageColorAllocate($image,$background_rgb['red'],
$background_rgb['green'],$background_rgb['blue']) ;
$font_color = ImageColorAllocate($image,$font_rgb['red'],
$font_rgb['green'],$font_rgb['blue']) ;
ImageTTFText($image,$font_size,0,-$box[0],abs($box[5]-$box[3])-$box[1],
$font_color,$font_file,$text) ;
// set transparency
if($transparent_background)
ImageColorTransparent($image,$background_color) ;
header('Content-type: ' . $mime_type) ;
ImagePNG($image) ;
// save copy of image for cache
if($cache_images)
{
@ImagePNG($image,$cache_filename) ;
}
ImageDestroy($image) ;
exit ;
/*
try to determine the "dip" (pixels dropped below baseline) of this
font for this size.
*/
function get_dip($font,$size)
{
$test_chars = 'abcdefghijklmnopqrstuvwxyz' .
'ABCDEFGHIJKLMNOPQRSTUVWXYZ' .
'1234567890' .
'!@#$%^&*()\'"\\/;.,`~<>[]{}-+_-=' ;
$box = @ImageTTFBBox($size,0,$font,$test_chars) ;
return $box[3] ;
}
/*
attempt to create an image containing the error message given.
if this works, the image is sent to the browser. if not, an error
is logged, and passed back to the browser as a 500 code instead.
*/
function fatal_error($message)
{
// send an image
if(function_exists('ImageCreate'))
{
$width = ImageFontWidth(5) * strlen($message) + 10 ;
$height = ImageFontHeight(5) + 10 ;
if($image = ImageCreate($width,$height))
{
$background = ImageColorAllocate($image,255,255,255) ;
$text_color = ImageColorAllocate($image,0,0,0) ;
ImageString($image,5,5,5,$message,$text_color) ;
header('Content-type: image/png') ;
ImagePNG($image) ;
ImageDestroy($image) ;
exit ;
}
}
// send 500 code
header("HTTP/1.0 500 Internal Server Error") ;
print($message) ;
exit ;
}
/*
decode an HTML hex-code into an array of R,G, and B values.
accepts these formats: (case insensitive) #ffffff, ffffff, #fff, fff
*/
function hex_to_rgb($hex)
{
// remove '#'
if(substr($hex,0,1) == '#')
$hex = substr($hex,1) ;
// expand short form ('fff') color
if(strlen($hex) == 3)
{
$hex = substr($hex,0,1) . substr($hex,0,1) .
substr($hex,1,1) . substr($hex,1,1) .
substr($hex,2,1) . substr($hex,2,1) ;
}
if(strlen($hex) != 6)
fatal_error('Error: Invalid color "'.$hex.'"') ;
// convert
$rgb['red'] = hexdec(substr($hex,0,2)) ;
$rgb['green'] = hexdec(substr($hex,2,2)) ;
$rgb['blue'] = hexdec(substr($hex,4,2)) ;
return $rgb ;
}
/*
convert embedded, javascript unicode characters into embedded HTML
entities. (e.g. '%u2018' => '‘'). returns the converted string.
*/
function javascript_to_html($text)
{
$matches = null ;
preg_match_all('/%u([0-9A-F]{4})/i',$text,$matches) ;
if(!empty($matches)) for($i=0;$i<sizeof($matches[0]);$i++)
$text = str_replace($matches[0][$i],
'&#'.hexdec($matches[1][$i]).';',$text) ;
return $text ;
}
?>
3）需要的字體
這里將需要的自己放在與js和php文件同在的一個目錄下（也可以修改，但是對應文件也要修改）
4）PHP的GD2庫
2，實現(xiàn)的html代碼
<?php
//load the popup utils library
//require_once 'include/popup_utils.inc.php';
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html>
<head>
<title>
Professional Search Engine Optimization with PHP: Table of Contents
</title>
<script type="text/javascript" language="javascript" src="dynatext/replacement.js"></script>
</head>
<body onload="window.resizeTo(800,600);" onresize='setTimeout("window.resizeTo(800,600);", 100)'>
<h1>
Professional Search Engine Optimization with PHP: Table of Contents
</h1>
<?php
//display popup navigation only when visitor comes from a SERP
// display_navigation();
//display_popup_navigation();
?>
<ol>
<li>You: Programmer and Search Engine Marketer</li>
<li>A Primer in Basic SEO</li>
<li>Provocative SE-Friendly URLs</li>
<li>Content Relocation and HTTP Status Codes</li>
<li>Duplicate Content</li>
<li>SE-Friendly HTML and JavaScript</li>
<li>Web Syndication and Social Bookmarking</li>
<li>Black Hat SEO</li>
<li>Sitemaps</li>
<li>Link Bait</li>
<li>IP Cloaking, Geo-Targeting, and IP Delivery</li>
<li>Foreign Language SEO</li>
<li>Coping with Technical Issues</li>
<li>Site Clinic: So You Have a Web Site?</li>
<li>WordPress: Creating a SE-Friendly Weblog?</li>
<li>Introduction to Regular Expression</li>
</ol>
</body>
</html>
3,使用效果前后對比
使用前
使用后
公眾號
事業(yè)單位
當前位置：
公考類
招聘類
各類考試