Passing an array in url data var

Question

I am trying to pass an array via the data var of an href link:

<a href="#" class="edit" data-myvar="<?php echo json_encode($row); ?>">Test</a>

I am using Jquery to process the variable:

$(function(){

     $('.edit').click(function(){

          var res=jQuery.parseJSON($(this).data("myvar"));

      console.log(res);

});


});

The console log says: Uncaught SyntaxError: Unexpected end of input

Any ideas?

Thanks.

To get that error you have to pass nothing into the parse function. Do a console.log of $(this).data("myvar") and see what that returns :) — Reinstate Monica Cellio
– Reinstate Monica Cellio, Commented Sep 16, 2013 at 15:52
Show us the actual rendered HTML, not with php tags in it, and we can help. It's the value that's in data-myvar that is the problem. — Reinstate Monica Cellio
– Reinstate Monica Cellio, Commented Sep 16, 2013 at 15:57

gustavohenke · Accepted Answer · 2013-09-16 16:23:33Z

1

First of all, apply htmlentities() in your json_encode() call to ensure that all quotes are okay in HTML.

jQuery already does JSON parsing on data- attributes for you, if it contains valid JSON syntax. So doing the following is the right way of doing it:

// this will contain the JSON presentation of $row variable from PHP.    
var res = $(this).data("myvar");

From the jQuery Docs:

Every attempt is made to convert the string to a JavaScript value (this includes booleans, numbers, objects, arrays, and null). A value is only converted to a number if doing so doesn't change the value's representation. For example, "1E02" and "100.000" are equivalent as numbers (numeric value 100) but converting them would alter their representation so they are left as strings. The string value "100" is converted to the number 100.

When the data attribute is an object (starts with '{') or array (starts with '[') then jQuery.parseJSON is used to parse the string; it must follow valid JSON syntax including quoted property names. If the value isn't parseable as a JavaScript value, it is left as a string.

Working fiddle

edited Sep 16, 2013 at 16:23

answered Sep 16, 2013 at 15:50

gustavohenke

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9 Comments

Alan A Over a year ago

ok I removed the json encode used within the HTML. Now when I try to access the array: res["user_id"]=undefined, res[0]=A, res[1]=r... and so on.. I'm confused

gustavohenke Over a year ago

You don't remove json_encode(), you remove $.parseJSON, which is done internally by jQuery itself.

gustavohenke Over a year ago

I have also enhanced my answer to better clarify future readers about this.

Alan A Over a year ago

I had already trried your suggestion, using json_encode on the html side and NOT using $.parseJSON. now my output is "undefined" for the 3 examples I provided above!

gustavohenke Over a year ago

So check the contents of your $row variable.

|

tymeJV · Accepted Answer · 2013-09-16 15:46:49Z

1

You never declare a variable:

var jQuery.parseJSON(res=$(this).data("myvar"));
                     ^ Not how to declare a variable

Should be:

var res = jQuery.parseJSON($(this).data("myvar"));

answered Sep 16, 2013 at 15:46

tymeJV

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3 Comments

Alan A Over a year ago

I have corrected my code, that was an error I made when making my post, the problem still exists with the correction

tymeJV Over a year ago

@AlanA -- You're also spelling edit wrong in your click handler. Also, what line is the error occurring on?

Alan A Over a year ago

Apologies 'edit' was a typo, my original code was spelt correctly

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