是否有Delphi标准函数用于转义HTML？ [英] Is there a Delphi standard function for escaping HTML?

问题描述

我有一个报告，应该采取网格控制并生成HTML输出。网格中的一列可以显示多个值，或< Any> 。当它输出到HTML时，当然最终会变为空白。

我可能会写一些例程来使用StringReplace将其转换为 & lt; Any& gt; ，所以它会正确显示这个特定的情况，但是我认为RTL中可能有一个已经被测试，并且是正确的。任何人都知道我在哪里可以找到它？

解决方案

我99％肯定这样的功能不存在于RTL的德尔福2009）。然而，当然，写这样一个功能是微不足道的。

更新

HTTPUtil.HTMLEscape是你正在寻找的：

  function HTMLEscape（const Str：string ）：string; 
  

我不敢在这里发布代码（侵犯版权，大概），但是例程是很简单。它将<，>，&和编码到& lt; ，& / code>，& amp; amp; 和& quot; ，还可以替换字符＃92 ，＃160 ..＃255到十进制代码，例如&＃92; 。

后一步是如果文件是UTF-8，则不必要，也是不合逻辑的，因为较高的特殊字符（如∮）保持原样，而较低的特殊字符（如×）被编码。

更新2

为了回应Stijn Sanders的回答，我做了一个简单的性能测试。

 程序Project1; 
 
 {$ APPTYPE CONSOLE} 
 
使用
 Windows，SysUtils; 
 
 var 
 t1，t2，t3，t4：Int64; 
i：整数; 
 str：string; 
 const 
 N = 100000; 
 
 
函数HTMLEncode（const Data：string）：string; 
 var 
i：Integer; 
 begin 
 
 result：=''; 
 for i：= 1 to length（Data ）do 
 case 
'<'：result：= result +'& lt;';的数据[i] 
'>'：result：= result +'& gt;'; 
'&'：result：= result +'& amp;'; 
'：result：= result +'& quot;'; 
 else 
 result：= result + Data [i]; 
 end; 
 
 end; 
 
 function HTMLEncode2（Data：string）：string; 
 begin 
结果：= 
 StringReplace（
 StringReplace（
 StringReplace（
 StringReplace（
 Data，
'&'，'& amp;'，[rfReplaceAll]），
'<'，'& '，[rfReplaceAll]），
'>'，'& gt;'，[rfReplaceAll]），
''，'& quot;'，[rfReplaceAll]）; 
结束
 
 begin 
 
 QueryPerformanceCounter（t1）; 
 for i：= 0 to N  -  1 do 
 str：= HTMLEncode（'Testing。Is 3 * 4< 3 + 4？你喜欢A& B 
 QueryPerformanceCounter（t2）; 
 
 QueryPerformanceCounter（t3）; 
 for i：= 0 to N  -  1 do 
 str：= HTMLEncode2（'Testing。Is 3 * 4< 3 + 4？你喜欢A& B 
 QueryPerformanceCounter（t4）; 
 
 Writeln（IntToStr（t2-t1））; 
 Writeln（IntToStr（t4-t3））; 
 
 Readln; 
 
 
结束。 
  

输出是

  532031 
 801969 
  

I've got a report that's supposed to take a grid control and produce HTML output. One of the columns in the grid can display any of a number of values, or <Any>. When this gets output to HTML, of course, it ends up blank.

I could probably write up some routine to use StringReplace to turn that into <Any> so it would display this particular case correctly, but I figure there's probably one in the RTL somewhere that's already been tested and does it right. Anyone know where I could find it?

解决方案

I am 99 % sure that such a function does not exist in the RTL (as of Delphi 2009). Of course - however - it is trivial to write such a function.

Update

HTTPUtil.HTMLEscape is what you are looking for:

function HTMLEscape(const Str: string): string;

I don't dare to publish the code here (copyright violation, probably), but the routine is very simple. It encodes "<", ">", "&", and """ to <, >, &, and ". It also replaces characters #92, #160..#255 to decimal codes, e.g. \.

This latter step is unnecessary if the file is UTF-8, and also illogical, because higher special characters, such as ∮ are left as they are, while lower special characters, such as ×, are encoded.

Update 2

In response to the answer by Stijn Sanders, I made a simple performance test.

program Project1;

{$APPTYPE CONSOLE}

uses
  Windows, SysUtils;

var
  t1, t2, t3, t4: Int64;
  i: Integer;
  str: string;
const
  N = 100000;


function HTMLEncode(const Data: string): string;
var
  i: Integer;
begin

  result := '';
  for i := 1 to length(Data) do
    case Data[i] of
      '<': result := result + '&lt;';
      '>': result := result + '&gt;';
      '&': result := result + '&amp;';
      '"': result := result + '&quot;';
    else
      result := result + Data[i];
    end;

end;

function HTMLEncode2(Data: string):string;
begin
  Result:=
    StringReplace(
    StringReplace(
    StringReplace(
    StringReplace(
      Data,
      '&','&amp;',[rfReplaceAll]),
      '<','&lt;',[rfReplaceAll]),
      '>','&gt;',[rfReplaceAll]),
      '"','&quot;',[rfReplaceAll]);
end;

begin

  QueryPerformanceCounter(t1);
  for i := 0 to N - 1 do
    str := HTMLEncode('Testing. Is 3*4<3+4? Do you like "A & B"');
  QueryPerformanceCounter(t2);

  QueryPerformanceCounter(t3);
  for i := 0 to N - 1 do
    str := HTMLEncode2('Testing. Is 3*4<3+4? Do you like "A & B"');
  QueryPerformanceCounter(t4);

  Writeln(IntToStr(t2-t1));
  Writeln(IntToStr(t4-t3));

  Readln;


end.

The output is

532031
801969

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