Sending JSON over xmlhttprequest

[madsovenielsen]

Hello everyone.Im trying to send a JSON string from a Classic ASP page over HTTP using xmlhttprequest. The string, as far as i can see, is being sendt fine. The formatting is fine. Its valid JSON. The JSON string from lookup.asp

{ "suggestResults" : [ {'name':'Madsen'},{'name':'Mads'},{'name':'Madsine'},{'name':'Mads-Emil'},{'name':'Madsbjerg'},{'name':'Madsbøll'},{'name':'Mads-Peter'},{'name':'Madsen-Østerbye'},{'name':'Mads-Christian'},{'name':'Madslund'},{'name':'dummy'}]};

Client side script

<script type="text/javascript">	function getData() {		if (window.XMLHttpRequest) {			xmlhttp = new XMLHttpRequest();		}		else {			xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");		}		xmlhttp.onreadystatechange = function () {			if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {								// var json = { "suggestResults" : [ {'name':'Madsen'},{'name':'Mads'},{'name':'Madsine'},{'name':'Mads-Emil'},{'name':'Madsbjerg'},{'name':'Madsbøll'},{'name':'Mads-Peter'},{'name':'Madsen-Østerbye'},{'name':'Mads-Christian'},{'name':'Madslund'},{'name':'dummy'}]};				var json = xmlhttp.responseText;				document.getElementById("name_dropdown").innerHTML = "";				var city_results = document.getElementById("name_dropdown");				var i = 0;				while (i < 10) {					city_results.innerHTML += '<div class="search_suggest_item">' + json.suggestResults[0].name + "</div>";					i++;				}			}		}		xmlhttp.open("GET", "../asp/lookup_name_company.asp?word=" + document.all.WHAT.value, true);		xmlhttp.send();	}</script>

We get the following error on the Client side:

Webpage error detailsUser Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0; SLCC1; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E)Timestamp: Mon, 10 Jan 2011 08:39:45 UTCMessage: 'suggestResults.0' is null or not an objectLine: 122Char: 17Code: 0

But when we embed the JSON string in a local variable on the clientside, all works fine. Any help is greatly appriciated./mads

[Synook]

The responseText is just a string - you need to parse that string into a JSON structure using JSON.parse().P.S. using single quotes is technically invalid JSON, but JavaScript accepts it.

[madsovenielsen]

The responseText is just a string - you need to parse that string into a JSON structure using JSON.parse().P.S. using single quotes is technically invalid JSON, but JavaScript accepts it.

I now use Douglas Crockford's json2.js lib.

function getData() {		if (window.XMLHttpRequest) {			xmlhttp = new XMLHttpRequest();		}		else {			xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");		}		xmlhttp.onreadystatechange = function () {			if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {				var json = xmlhttp.responseText;				var test1 = JSON.stringify(json);				//alert(test1);				var testvar2 = JSON.parse(test1);				//alert(testvar2);				document.getElementById("name_dropdown").innerHTML = "";				var city_results = document.getElementById("name_dropdown");				var i = 0;				while (i < 10) {					city_results.innerHTML += '<div class="search_suggest_item" onclick="extractToField(this.innerHTML;)">' + testvar2.suggestResults[0].name + "</div>";					i++;				}			}		}		xmlhttp.open("GET", "../asp/lookup_name_company.asp?word=" + sWHAT, true);		xmlhttp.send();	}

I get the same error:

Webpage error detailsUser Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0; SLCC1; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E)Timestamp: Mon, 10 Jan 2011 08:39:45 UTCMessage: 'suggestResults.0' is null or not an objectLine: 122Char: 17Code: 0

If i alert(test1); and alert(testvar2); i get valid JSON in both cases./mads

[jeffman]

if JSON.parse is doing its job, then alert(testvar2) would not display a json string at all. It would alert something like [Object object]

[madsovenielsen]

if JSON.parse is doing its job, then alert(testvar2) would not display a json string at all. It would alert something like [Object object]

Okay. do you know what i am doing wrong ?/mads

[jeffman]

My guess is that calling JSON.stringify is messing things up. xmlhttp.responseText is already a string. I can't even guess what would happen to the syntax if you stringified a string. stringify is designed to turn a javascript object into a string that conforms to JSON syntax.In other words, try passing xmlhttp.responseText directly to JSON.parse

[madsovenielsen]

My guess is that calling JSON.stringify is messing things up. xmlhttp.responseText is already a string. I can't even guess what would happen to the syntax if you stringified a string. stringify is designed to turn a javascript object into a string that conforms to JSON syntax.In other words, try passing xmlhttp.responseText directly to JSON.parse

Im am now passing xmlhttp.responseText directly to JSON.parse()And i get the following error:

Webpage error detailsUser Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0; SLCC1; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E)Timestamp: Mon, 10 Jan 2011 17:32:52 UTCMessage: Syntax errorLine: 25Char: 13Code: 0

[justsomeguy]

What does the string look like that you're trying to parse? Are you using double quotes in the string?

[thescientist]

I would guess that if your JSON doesn't validate here http://www.jsonlint.com/(which your's doesn't) then, you might want to consider making it double quotes, especially if you are using the JSON library. (the library and validator are both written by the same person)

[madsovenielsen]

What does the string look like that you're trying to parse? Are you using double quotes in the string?

{ "suggestResults" : [ {'name':'Grethe'},{'name':'Gerda'},{'name':'Gitte'},{'name':'Gudrun'},{'name':'Gunnar'},{'name':'Georg'},{'name':'Gert'},{'name':'Grete'},{'name':'Gustav'},{'name':'Gurli'},{'name':'dummy'}]}

Based on this example on json.org

var myJSONObject = {"bindings": [		{"ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*"},		{"ircEvent": "PRIVMSG", "method": "deleteURI", "regex": "^delete.*"},		{"ircEvent": "PRIVMSG", "method": "randomURI", "regex": "^random.*"}	]};

http://www.json.org/js.html/mads

[madsovenielsen]

I would guess that if your JSON doesn't validate here http://www.jsonlint.com/(which your's doesn't) then, you might want to consider making it double quotes, especially if you are using the JSON library. (the library and validator are both written by the same person)

I will try to use double quotes. I dont think it will be easy, we are using classic asp. so a single quote is used for comments :)/mads

[madsovenielsen]

Thanks all. Its working now. using only double quotes./mads