Strange XML structrue after Facebook call.

Core Library Questions

mr.t

Strange XML structrue after Facebook call.

in Core Library Questions • 10 months ago

I am trying to access profile data via the Facebook Graph Api like described here:

http://wiki.processing.org/w/Facebook,_REST_API

I have to say. I am very unexperienced with XML.

So this might be a real noob question.

what I get is an XMLElemn which looks like this:

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<<?xml version="1.0" encoding="UTF-8"?>
<Users_getInfo_response xmlns="http://api.facebook.com/1.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://api.facebook.com/1.0/ http://api.facebook.com/1.0/facebook.xsd" list="true">
<user>
<uid>1477411208</uid>
<first_name>Marc</first_name>
<last_name>Tiedemann</last_name>
</user>
</Users_getInfo_response>/>

looks good to me. but when I try to access the children, i get null back!

instead everything seems to be root!

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println("childs "+ xml.hasChildren());
println("root "+ xml.getName());

console output:

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childs false
root <?xml version="1.0" encoding="UTF-8"?>
<Users_getInfo_response xmlns="http://api.facebook.com/1.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://api.facebook.com/1.0/ http://api.facebook.com/1.0/facebook.xsd" list="true">
<user>
<uid>1477411208</uid>
...

I also read that this method of getting info from the Graph API is kinda outdated. As REST got depriciated.

Does anybody have a running example of how you could do this better?

As said I am very very new to this kind of coding and happy for any hint's in the right direction.

Replies(9)

PhiLho

Re: Strange XML structrue after Facebook call.

10 months ago

How do you initialize the xml variable?
Also, are you using 1.5.1 or 2.0b? The XML handling changes a lot between the two versions. The wiki probably refers to the old method.

mr.t

Re: Strange XML structrue after Facebook call.

10 months ago

I am using 1.5.1 for now. Would you recon switching to the new one?

I really just did a straight copy and paste from the wiki. So initialization goes like this:

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String xmlResponse = fbCallMethod( new String[] {
"method=facebook.Users.getInfo",
"uids=" + fbUserIDs,
"fields=uid,first_name,last_name", // see link above for more options
"format=XML"
});
XMLElement xml = new XMLElement( xmlResponse );
println(xml);

PhiLho

Re: Strange XML structrue after Facebook call.

10 months ago

The page you link to uses:

usersXml = xml.getChildren( "user" );

So it skips the cruft and jumps straight at the useful data.

mr.t

Re: Strange XML structrue after Facebook call.

10 months ago

yeah. but then i get null pointer. check out my first entry. there are no childs. just a big root!

PhiLho

Re: Strange XML structrue after Facebook call.

10 months ago

I see the last line:
</Users_getInfo_response> />
If that's the real data and not a copy / paste error, then the XML is wrong and Processing is confused.

mr.t

Re: Strange XML structrue after Facebook call.

10 months ago

aha.. he does that when parsing the String to the XMLElement. So the String is right:

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<Users_getInfo_response xmlns="http://api.facebook.com/1.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://api.facebook.com/1.0/ http://api.facebook.com/1.0/facebook.xsd" list="true">
<user>
<uid>1477411208</uid>
<first_name>Marc</first_name>
<last_name>Tiedemann</last_name>
</user>
</Users_getInfo_response>

but XMLElement adds the outer brakets:

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<<?xml version="1.0" encoding="UTF-8"?>
...
</Users_getInfo_response>/>

still it shouldn't do this, if i understand right.

PhiLho

Re: Strange XML structrue after Facebook call.

10 months ago

Try replacing
XMLElement xml = new XMLElement(xmlResponse);
with
XMLElement xml = XMLElement.parse(xmlResponse);

mr.t

Re: Re: Strange XML structrue after Facebook call.

10 months ago

Thanx PhiLho! that did it!

what is the difference here?

PhiLho

Re: Strange XML structrue after Facebook call.

10 months ago

I don't have the 1.5 code at hand right now, but I think the difference is that the XMLElement constructor with a string isn't designed to parse an XML string...
IIRC, it is actually made to create a new single node with the given string as tag name.

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