How to sanitize user input text so that it can be used in JavascriptJSON? - Stack Overflow

admin管理员组

文章数量:1327711

I have a web app in which I allow some large text entry using text fields. This text is saved to a database and then later it is sent back to the user as a field in a JSON response. In the browser, I attempt to simply convert it to an Object using JSON.parse, but this sometimes fails depending on what the user put in the field.

I think that right now, the text has single quotes in it, and those are breaking the browser-side Javascript before I can call JSON.parse on it.

What's the best way to sanitize this data so that, ideally, I can just parse it back to an Object with minimal cleansing after it has been saved?

I have a web app in which I allow some large text entry using text fields. This text is saved to a database and then later it is sent back to the user as a field in a JSON response. In the browser, I attempt to simply convert it to an Object using JSON.parse, but this sometimes fails depending on what the user put in the field.

I think that right now, the text has single quotes in it, and those are breaking the browser-side Javascript before I can call JSON.parse on it.

What's the best way to sanitize this data so that, ideally, I can just parse it back to an Object with minimal cleansing after it has been saved?

• javascript
• json

Share Improve this question Follow asked Jan 2, 2013 at 16:45 RyanRyan 7,9571111 gold badges6666 silver badges119119 bronze badges 3

• can you bine this with php? – s_p Commented Jan 2, 2013 at 16:47
• You should not sanitize input. You need to make sure your JSON is well formed by using one of the standard JSON writers. – Ilia G Commented Jan 2, 2013 at 16:47
• The problem lies with whatever it is you're using to encode the JSON at the server. (It's almost certainly not a single-quote character problem, as JSON strings must be quoted with double-quotes, not single-quotes.) – Pointy Commented Jan 2, 2013 at 16:47

Add a ment  | 

2 Answers 2

Sorted by: Reset to default 6

This isn't a sanitization problem : you can very well put a string with quotes in JSON : the encoding simply escapes them.

Your problem is an encoding one. To build a JSON string in a browser, use JSON.stringify. To do it server side, you should use the tool provided by your (unmentionned) server side language/framework.

The awesome thing with JSON is that you do not need to sanitize anything. No matter what you feed to a JSON encoder - it will always output plain JSON. Obviously that JSON needs to be HTML-encoded in case you plan to use it within a HTML page. Depending on the JS encoder you need to ensure there's no </script> in there (e.g. by replacing / with \/).

You also do not need JSON.parse. JSON is a subset of JavaScript so you can do something like that (PHP-ish for simplicity):

<script>
    var obj = <?= json_encode($whatever) ?>;
</script>

---

If you really want to include JSON as as tring inside JSON consider not doing it. You can just have the object itself there - no need to have a JSON string within your JSON data. But if you have this anyway it should also always work.

本文标签： How to sanitize user input text so that it can be used in JavascriptJSONStack Overflow