URL encoding/decoding: what changed

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Title: URL encoding/decoding

New		Line
1	+	Question: I need to pass some arbitrary text as a query string to a URL that will be opened in the default browser via OpenURL. Obviously, the query string will need to be URL-encoded - is there a standard function somewhere for this?
2	+
3	+	Answer-1: You have httpprotocol.HTTPEncode and httpprotocol.HTTPDecode.
4	+
5	+	``` Pascal
6	+	uses
7	+	httpprotocol;
8	+	var
9	+	A, B: string;
10	+	begin
11	+	A := 'http://www.somesite.com/page1.asp?id=65';
12	+	B := HTTPEncode(A);
13	+	A := HTTPDecode(B);
14	+	```
15	+
16	+	Answer-2: Here are ready functions, written by forum member BenJones.
17	+
18	+	``` Pascal
19	+	function EncodeUrl(const url: string): string;
20	+	var
21	+	x: integer;
22	+	sBuff: string;
23	+	const
24	+	SafeMask = ['A'..'Z', '0'..'9', 'a'..'z', '*', '@', '.', '_', '-'];
25	+	begin
26	+	//Init
27	+	sBuff := '';
28	+
29	+	for x := 1 to Length(url) do
30	+	begin
31	+	//Check if we have a safe char
32	+	if url[x] in SafeMask then
33	+	begin
34	+	//Append all other chars
35	+	sBuff := sBuff + url[x];
36	+	end
37	+	else if url[x] = ' ' then
38	+	begin
39	+	//Append space
40	+	sBuff := sBuff + '+';
41	+	end
42	+	else
43	+	begin
44	+	//Convert to hex
45	+	sBuff := sBuff + '%' + IntToHex(Ord(url[x]), 2);
46	+	end;
47	+	end;
48	+
49	+	Result := sBuff;
50	+	end;
51	+
52	+	function DecodeUrl(const url: string): string;
53	+	var
54	+	x: integer;
55	+	ch: string;
56	+	sVal: string;
57	+	Buff: string;
58	+	begin
59	+	//Init
60	+	Buff := '';
61	+	x := 1;
62	+	while x <= Length(url) do
63	+	begin
64	+	//Get single char
65	+	ch := url[x];
66	+
67	+	if ch = '+' then
68	+	begin
69	+	//Append space
70	+	Buff := Buff + ' ';
71	+	end
72	+	else if ch <> '%' then
73	+	begin
74	+	//Append other chars
75	+	Buff := Buff + ch;
76	+	end
77	+	else
78	+	begin
79	+	//Get value
80	+	sVal := Copy(url, x + 1, 2);
81	+	//Convert sval to int then to char
82	+	Buff := Buff + char(StrToInt('$' + sVal));
83	+	//Inc counter by 2
84	+	Inc(x, 2);
85	+	end;
86	+	//Inc counter
87	+	Inc(x);
88	+	end;
89	+	//Return result
90	+	Result := Buff;
91	+	end;
92	+
93	+	procedure TForm1.Button1Click(Sender: TObject);
94	+	var
95	+	A, B: string;
96	+	begin
97	+	A := 'http://www.somesite.com/page1.asp?id=65';
98	+	//Encode url
99	+	B := EncodeUrl(A);
100	+	//Show Encoded url
101	+	ShowMessage(B);
102	+	//Show deoded url
103	+	ShowMessage(DecodeUrl(B));
104	+	end;
105	+	```
106	+
107	+	---
108	+	From the Free Pascal wiki, page "URL encoding/decoding", as it stood on 2021-12-11 after a change by Alextp, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's [[Licensing]] page. If you have concerns about this material, [message the admin](/wiki-contact).

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