Be careful if you're assuming that arg_separator defaults to "&".
For me, with my xampp installation and PHP 5.2.1, this was scary:
[php.ini]
; The separator used in PHP generated URLs to separate arguments.
; Default is "&".
arg_separator.output = "&"
... as it gave me a complete headache debugging something, as I expected the string length to be the length of the string my browser was displaying. I was so certain arg_separator was "&" because I'd never changed my php.ini that it took me seemingly forever to consider looking at the source code.
D'oh.
This may seem irrelevant at first (and I realise my case is an unusual way of stumbling into this issue), but since, if you run htmlspecialchars() over "&", the result will be "&", DON'T expect a one- or two-parameter http_build_query() to return a query you still have to run through htmlspecialchars().
I suggest using the third parameter to retain your sanity.
http_build_query
(PHP 5, PECL pecl_http:0.1.0-0.9.0)
http_build_query — URL エンコードされたクエリ文字列を生成する
説明
string http_build_query ( array $formdata [, string $numeric_prefix [, string $arg_separator]] )与えられた連想配列 (もしくは添字配列) から URL エンコードされたクエリ文字列を生成します。
パラメータ
- formdata
プロパティを含む配列もしくはオブジェクト。
配列の形式は、単純な一次元構造、 もしくは配列の配列 (言い換えると、他の配列を含む配列) となります。
- numeric_prefix
もし数値インデックスが基底となる配列に使用されたり numeric_prefix が指定された場合、 基底となる配列の要素に対する数値インデックスの前にこれが追加されます。
これは、後で PHP や他の CGI アプリケーションによってデータがデコードされる際、 正当な変数名になるよう考慮したものです。
- arg_separator
arg_separator.output が区分のためのセパレータとして使用されます。ただし、 このパラメータが指定されていた場合は それが使用されます。
返り値
URL エンコードされた文字列を返します。
変更履歴
| バージョン | 説明 |
|---|---|
| 5.1.2 | パラメータ arg_separator が追加されました。 |
| 5.1.3 | 角括弧がエスケープされるようになりました。 |
例
例 2498. http_build_query() の簡単な使用法
<?php
$data = array('foo'=>'bar',
'baz'=>'boom',
'cow'=>'milk',
'php'=>'hypertext processor');
echo http_build_query($data); // foo=bar&baz=boom&cow=milk&php=hypertext+processor
echo http_build_query($data, '', '&'); // foo=bar&baz=boom&cow=milk&php=hypertext+processor
?>
例 2499. 数値インデックス要素の場合での http_build_query()
<?php
$data = array('foo', 'bar', 'baz', 'boom', 'cow' => 'milk', 'php' =>'hypertext processor');
echo http_build_query($data) . "\n";
echo http_build_query($data, 'myvar_');
?>
上の例の出力は以下となります。
0=foo&1=bar&2=baz&3=boom&cow=milk&php=hypertext+processor myvar_0=foo&myvar_1=bar&myvar_2=baz&myvar_3=boom&cow=milk&php=hypertext+processor
例 2500. 複雑な配列の場合での http_build_query()
<?php
$data = array('user'=>array('name'=>'Bob Smith',
'age'=>47,
'sex'=>'M',
'dob'=>'5/12/1956'),
'pastimes'=>array('golf', 'opera', 'poker', 'rap'),
'children'=>array('bobby'=>array('age'=>12,
'sex'=>'M'),
'sally'=>array('age'=>8,
'sex'=>'F')),
'CEO');
echo http_build_query($data, 'flags_');
?>
この例は以下を出力します: (可読性のため適宜折り返しています)
user%5Bname%5D=Bob+Smith&user%5Bage%5D=47&user%5Bsex%5D=M& user%5Bdob%5D=5%2F12%2F1956&pastimes%5B0%5D=golf&pastimes%5B1%5D=opera& pastimes%5B2%5D=poker&pastimes%5B3%5D=rap&children%5Bbobby%5D%5Bage%5D=12& children%5Bbobby%5D%5Bsex%5D=M&children%5Bsally%5D%5Bage%5D=8& children%5Bsally%5D%5Bsex%5D=F&flags_0=CEO
注意: 基底の配列内の数値インデックス要素 "CEO" のみ、 接頭辞を受け取ります。pastimes 以下にある他の数値インデックスは、 正当な変数名にするための文字列の接頭辞を要求しません。
例 2501. オブジェクトの場合の http_build_query() の使用
<?php
class myClass {
var $foo;
var $baz;
function myClass() {
$this->foo = 'bar';
$this->baz = 'boom';
}
}
$data = new myClass();
echo http_build_query($data); // foo=bar&baz=boom
?>
参考
| parse_str() |
| parse_url() |
| urlencode() |
| array_walk() |
http_build_query
pinkgothic at gmail dot com
27-Apr-2007 06:24
27-Apr-2007 06:24
mqchen at gmail dot com
04-Feb-2007 06:27
04-Feb-2007 06:27
To flyingmeteor,
Your function is pleasingly adequate, however, when comparing the results from your function with the results from the actual function, it has a minor defect. If one uses a special character (e.g. øæåöä) in a key in the $data array, it is not encoded by your function, but it is by the actual one.
This is easily solved by some minor edits:
<?php
if(!function_exists('http_build_query')) {
function http_build_query($data,$prefix=null,$sep='',$key='') {
$ret = array();
foreach((array)$data as $k => $v) {
$k = urlencode($k);
if(is_int($k) && $prefix != null) {
$k = $prefix.$k;
};
if(!empty($key)) {
$k = $key."[".$k."]";
};
if(is_array($v) || is_object($v)) {
array_push($ret,http_build_query($v,"",$sep,$k));
}
else {
array_push($ret,$k."=".urlencode($v));
};
};
if(empty($sep)) {
$sep = ini_get("arg_separator.output");
};
return implode($sep, $ret);
};
};
?>
Forgive my personal coding standard.
havelka at valka dot cz
22-Dec-2006 08:37
22-Dec-2006 08:37
I think it doesnt :( when processing array let say from MySQL db, where array is list of rows (column - value), it generates the first "row" without indexes (post_subject=xxx&post_detail=yyy) while the other rows are indexed well ( 1[post_subject]=xxx&1[post_details]=yyy )
this causes confusion when the array is read back from this string (because the first line, without index is ignored (put to another variable than rest of the array), also count of this array says n+x (N = amount of rows in the array, X = amount of columns in the first row) which is wrong. The correct way should look like
0[post_subject]=xxx&0[post_detail]=yyy
for the first entry and then to continue with the rest
flyingmeteor at gmail dot com
12-Dec-2006 02:46
12-Dec-2006 02:46
Here is another equivalent function for users that don't have PHP5 yet, it behaves the same way as the PHP5 counterpart and has one extra parameter for added functionality.
<?php
if (!function_exists('http_build_query')) {
function http_build_query($data, $prefix='', $sep='', $key='') {
$ret = array();
foreach ((array)$data as $k => $v) {
if (is_int($k) && $prefix != null) $k = urlencode($prefix . $k);
if (!empty($key)) $k = $key.'['.urlencode($k).']';
if (is_array($v) || is_object($v))
array_push($ret, http_build_query($v, '', $sep, $k));
else array_push($ret, $k.'='.urlencode($v));
}
if (empty($sep)) $sep = ini_get('arg_separator.output');
return implode($sep, $ret);
}}
?>
Colin Guthrie
09-Mar-2006 12:11
09-Mar-2006 12:11
I am concerned about this function's generation of [ and ] in the variable names.
From what I can gather from http://www.faqs.org/rfcs/rfc3986.html (which I believe to be the most recent RFC on the matter), the use of square brackets is illegal here.
To be sure, always use the following:
str_replace(array('[',']'), array('%5B','%5D'), http_build_query($data));
I will also submit a bug, but thought it important to inform users.
Colin Guthrie
08-Mar-2006 11:25
08-Mar-2006 11:25
@ xangelusx
You said that "It is actually illegal to set arg_separator.output to & ("and amp ;") as every character is considered a seperator according to the documentation."
I don't think this is correct. arg_separator.input maybe, but not the output. How can PHP encode my URLs (that is what this setting is used for, e.g. on URL rewriting etc.) with more than one separator? It doesn't make sence for that variable.
I have personally used & as a separate for output for years in order to create valid XHTML output via PHP.
I long ago wrote a function to do this for me, but depending on where I use the output, I sometimes want & and sometimes just a plain old & (think putting the value in a href="" versus using it in a Location: header). Unfortunatly, I can see no way to deprecate my function just yet, as this built in function is lacking that distinction (an optional argument would be perfect IMO)
Ilya Rudenko
10-Jan-2006 04:57
10-Jan-2006 04:57
Params with null value do not present in result string.
<?
$arr = array('test' => null, 'test2' => 1);
echo http_build_query($arr);
?>
will produce:
test2=1
vlad_mustafin at ukr dot net
05-Oct-2005 09:03
05-Oct-2005 09:03
Dear anonymous, i think that your example is incorrect in some places (or at least is not flexible) and shortly only in names of variables (as $c, $k, etc.) and some spaces and line foldings :), i can explain:
1. I think that next part of code is not wanted here:
<?if (!is_array($a)) return false;?>
because you have (array)$a in foreach! It is possible but not obligatory. Or maybe better to use trigger_error for this situation.
2. You don't use urlencode on key! It's wrong because it can have also unsafe value!
<?if ($c) $k=$b."[".$k."]"; elseif (is_int($k)) $k=$b.$k;?>
this part is wrong because $k can be integer even if $c is not empty. I can want to add numeric_prefix to all indexes in array, but your example will not allow to make it. Here using of elseif is excluded, these both conditions should exist simultaneously.
3. <?http_build_query($v,$k,1);?> - In my opinion it's a very rough error. You use second parameter (as "numeric_prefix" in my example and php manual for this function) for transfer of the current key into next iteration step of recursion. Certainly it's possible and is not of principle, but very not professionally, in my opinion. I use implicit rule: one ought not to violate function logic even inside of the same function one may only expand logic. And my <?http_build_query($v, null, $tmp_key);?> allows to add numeric_prefix to all indexes in array (see point 2), i need just to put $numeric_prefix instead of null into second parameter.
Also i want to extend my previous example because we must use ini_get('arg_separator.output') instead of '&' separator!
<?
if(!function_exists('http_build_query')) {
function http_build_query( $formdata, $numeric_prefix = null, $key = null ) {
$res = array();
foreach ((array)$formdata as $k=>$v) {
$tmp_key = urlencode(is_int($k) ? $numeric_prefix.$k : $k);
if ($key) $tmp_key = $key.'['.$tmp_key.']';
if ( is_array($v) || is_object($v) ) {
$res[] = http_build_query($v, null /* or $numeric_prefix if you want to add numeric_prefix to all indexes in array*/, $tmp_key);
} else {
$res[] = $tmp_key."=".urlencode($v);
}
/*
If you want, you can write this as one string:
$res[] = ( ( is_array($v) || is_object($v) ) ? http_build_query($v, null, $tmp_key) : $tmp_key."=".urlencode($v) );
*/
}
$separator = ini_get('arg_separator.output');
return implode($separator, $res);
}
}
?>
All best!
04-Oct-2005 05:33
I made my very own http_build_query function quite some time ago for php 4 and below. Works exactly like the function below; but its just a bit shorter. :P
<?
function http_build_query($a,$b='',$c=0){
if (!is_array($a)) return false;
foreach ((array)$a as $k=>$v){
if ($c) $k=$b."[".$k."]"; elseif (is_int($k)) $k=$b.$k;
if (is_array($v)||is_object($v)) {$r[]=http_build_query($v,$k,1);continue;}
$r[]=$k."=".urlencode($v);
}
return implode("&",$r);
}
?>
vlad_mustafin at ukr dot net
29-Sep-2005 08:31
29-Sep-2005 08:31
My example of this function for PHP versions < PHP5 without any regular expressions, just cycles, recursion and standard functions. It can work with complex arrays or objects or both combined.
<?php
if(!function_exists('http_build_query')) {
function http_build_query( $formdata, $numeric_prefix = null, $key = null ) {
$res = array();
foreach ((array)$formdata as $k=>$v) {
$tmp_key = urlencode(is_int($k) ? $numeric_prefix.$k : $k);
if ($key) {
$tmp_key = $key.'['.$tmp_key.']';
}
if ( is_array($v) || is_object($v) ) {
$res[] = http_build_query($v, null, $tmp_key);
} else {
$res[] = $tmp_key."=".urlencode($v);
}
}
return implode("&", $res);
}
}
?>
php dot net at hiddemann dot org
12-May-2005 10:22
12-May-2005 10:22
This is a workaround for PHP versions < PHP5. It does not work with complex arrays, however.
<?
if (!function_exists('http_build_query')) {
function http_build_query($formdata, $numeric_prefix = "")
{
$arr = array();
foreach ($formdata as $key => $val)
$arr[] = urlencode($numeric_prefix.$key)."=".urlencode($val);
return implode($arr, "&");
}
}
?>
aidan at php dot net
28-May-2004 12:25
28-May-2004 12:25
This functionality is now implemented in the PEAR package PHP_Compat.
More information about using this function without upgrading your version of PHP can be found on the below link:
http://pear.php.net/package/PHP_Compat