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up vote 0 down vote favorite

I am perplexed and cannot figure out why this JSON object code is not coming out like I think it should.

For reasons not important to theis example, the PHP array is created from another array. As a PHP array, this works fine.

for($i=0;$i<$FileCount;$i++)
{
    $FileList[$i] = array
    (
        "Category" => $Category, "FileName" => $FileName, "Ext" => $Ext, "Title" => $Title, "ShortName" => $ShortName
    );
}

print_r($FileList);
Array ( [0] => Array ( [Category] => AntiqueGlass [FileName] => AntiqueGlass-BlackGlassBox-B [Ext] => jpg [Title] => BlackGlassBox [ShortName] => AntiqueGlass-BlackGlassBox ) [1] => Array ( [Category] => AntiqueGlass [FileName] => AntiqueGlass-BluePicture-B [Ext] => jpg [Title] => BluePicture [ShortName] => AntiqueGlass-BluePicture ) )

I then do this, with the result of the write shown underneath

$json_array=json_encode($FileList);
echo('
<script type="text/javascript">
    var JSFileList = '.json_encode($json_array, JSON_FORCE_OBJECT).';
    document.write(JSFileList);
</script>'."\n");

[{"Category":"AntiqueGlass","FileName":"AntiqueGlass-BlackGlassBox-B","Ext":"jpg","Title":"BlackGlassBox","ShortName":"AntiqueGlass-BlackGlassBox"},{"Category":"AntiqueGlass","FileName":"AntiqueGlass-BluePicture-B","Ext":"jpg","Title":"BluePicture","ShortName":"AntiqueGlass-BluePicture"}]

I believe the result should come out something like this

{"0":("Category":"AntiqueGlass","FileName":"AntiqueGlass-BlackGlassBox-B","Ext":"jpg","Title":"BlackGlassBox","ShortName":"AntiqueGlass-BlackGlassBox")},{"1":("Category":"AntiqueGlass","FileName":"AntiqueGlass-BluePicture-B","Ext":"jpg","Title":"BluePicture","ShortName":"AntiqueGlass-BluePicture")}

The intent is to access the object like this

JSFileList[i].FileName

All my research says this should work. I am at a loss to know what I am doing wrong.

share|improve this question
    
Why use force object? What you ant in JavaScript is an array of objects. Just plain old json_encode will be fine if you only call it once. –  Mike Brant Feb 3 at 6:49
    
It's really unnecessary, as json_encode will force it anyway, because it is, at lease partly, an associative array. –  RationalRabbit Feb 3 at 6:53
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3 Answers

up vote 1 down vote accepted

You are calling json_encode twice:

$json_array=json_encode($FileList);
//.....
json_encode($json_array, JSON_FORCE_OBJECT);

you must use the JSON_FORCE_OBJECT-option in the first call, after that $json_array already is a String, JSON_FORCE_OBJECT will have no effect there.

Of course the resulting variable JSFileList with the double-encoding will also be a string, when you need to access the object in JS encode it only 1 time(document.write then would print something like [object Object]).

share|improve this answer
    
+1 I overlooked that problem. –  deceze Feb 3 at 6:40
    
As did I, obviously (grin). Got lost somewhere in my experimenting ... And that was the problem. –  RationalRabbit Feb 3 at 6:48
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up vote 0 down vote 
[{...},{...},{...}]

This is an array of objects. You can access the individual objects by the numeric array index, like JSFileList[2].FileName. It already works as you need it.

Javascript distinguishes between continuously numerically indexed arrays ([]) and associative objects ({}), PHP does not. json_encode encodes all continuously numerically indexed PHP arrays to Javascript arrays, anything else to objects.

share|improve this answer
    
The result of JSFileList[0].FileName is [. The result of JSFileList[1].FileName is (. The result of JSFileList[2].FileName is ". –  RationalRabbit Feb 3 at 6:31
    
Cannot reproduce. jsfiddle.net/VQHtp –  deceze Feb 3 at 6:38
    
CORRECTION: The result of JSFileList[0].FileName is undefined. The result of JSFileList[0] is [ . The result of JSFileList[1] is (, etc. –  RationalRabbit Feb 3 at 6:40
    
Actually yes, because of stackoverflow.com/a/21521138/476. Combine that and my answer. –  deceze Feb 3 at 6:41
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up vote -1 down vote

It is an array of objects. You are not able to access JSFileList[i].FileName because they are in string form. You need to use JSON.parse().

echo('
<script type="text/javascript">
    var JSFileList = JSON.parse('.json_encode($json_array, JSON_FORCE_OBJECT).');
    document.write(JSFileList[0].FileName);
</script>'."\n");
share|improve this answer
    
Why the downvote? Am I wrong? –  Kamehameha Feb 3 at 6:19
    
No, he's not outputting it as a string in Javascript, it's an object/array literal in the JS source. –  deceze Feb 3 at 6:20
    
Ah... but when I echo json_encode() from PHP, and when I use it as an input in javaScript, won't it be text? I tried it out, and i am able to access JSFileList[i].FileName from Javascript. –  Kamehameha Feb 3 at 6:36
    
You're echoing Javascript source code as text with JSON as text embedded in it... If the resulting source code looks like jsfiddle.net/VQHtp it's not text to Javascript. –  deceze Feb 3 at 6:39
    
Yes, I am echoing out JS as text,since it was in the question.The asker has said that and he intends to use JSFileList[i].FileName after performing the above said operation. So doesn't it solve the purpose? Sorry if I am being thick... –  Kamehameha Feb 3 at 6:46
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