Google Gadget Widget

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(this documentation is incomplete)

The Google Gadget Widget is a Wiki Widget that embeds a Google Gadget on a wiki page.

Contents

[edit] Example

Here's an example 

 
  <widget 
    type="googlegadget" 
    url="http://horloge.maree.frbateaux.net/gh.xml" 
    xargs="up_Port=401&up_UTC=0"
    synd="open" 
    width="320" 
    height="222" 
    title="Mareas en Bilbao" 
    border="http://gmodules.com/ig/images/" 
    output="js" />

And here's what it looks like:

Note the use of the xargs attribute to handle arguments whose names are not valid XML attribute names - in this case up_Port and up_UTC. Thanks to Juan Zubeldia for pointing out the need for this mechanism.

[edit] Reference

[edit] Parameters

(this documentation is incomplete)

debug
display debug information for the widget (default 0)
disabled
temporarily disable display of widget (default 0)
width
sets the width of the embedded calendar in pixels (default 320)
height
sets the height of the embedded calendar in pixels (default 75)
title
the title for the search box
border
the border style for the search box
xargs
contains any arguments that can't be expressed as XML attributes

[edit] Escaping Arguments

Read this if you're having difficulty getting your Google Gadget working. I'm afraid I've made it sound terribly complex. If anyone can think of a clearer way to say the same thing please feel free to edit --AndyArmstrong

Wiki Widgets use XML syntax. In XML (like HTML) the characters '<', '>' and '&' have special meanings. That means that if you need to use one of those characters in an attribute value it must be encoded. For example, let's suppose you want your gadget's title to be "Law & Order". The ampersand is a special character in XML so it has to be encoded. Instead of 

 
  <widget type="googlegadget" title="Law & Order" />

you'd use 

 
  <widget type="googlegadget" title="Law &amp; Order" />

The '&' is replaced by '&amp;'. Similarly '<' is replaced by '&lt;' and '>' is replaced by '&gt;'.

[edit] The xargs Attribute

Things get even more complicated in the case of the xargs attribute which allows multiple parameters to be passed - and in particular parameters whose names are not valid XML attribute names.

The arguments contained in xargs are encoded in the same way that multiple arguments are encoded in a URL. For example 

 x=1&y=2

encodes two arguments - x which is equal to 1 and y equal to 2. Because '&' and '=' are used to separate the parameters and values these characters (along with a number of others) can't appear within parameter values. Instead these characters are encoded as '%' followed by their ASCII character code in hexadecimal. So the text "Law & Order" would be encoded as 

 Law%20%26%20Order

Optionally the plus sign '+' may be used instead of '%20' to represent spaces.

[edit] Putting it all together

So that's all a bit complex I'm afraid. Here's how it works in practice. Let's say your Google Gadget needs a parameter called 'src_URL' with a value of 

 
  http://example.com/rss?id=123&limit=40

That presents two problems:

  • src_URL isn't a valid XML attribute name
  • the URL contains an ampersand which we'll need to encode

Because src_URL can't be used as the name of one of our XML attributes we'll have to put it inside the xargs attribute. Values in xargs are URL encoded so we'll need something like this: 

 
  <widget type="googlegadget" xargs="src_URL=http%3A%2F%2Fexample.com%2Frss%3Fid%3D123%26limit%3D40" />

Notice how most of the punctuation in the URL has been encoded using the '%xx' notation. In particular the ampersand has gone so we don't need to worry additionally about XML entity encoding. Phew.

For attributes other than xargs we do need to consider XML entity encoding so if we add the title "Law & Order" to that we get 

 
  <widget 
    type  = "googlegadget" 
    title = "Law &amp; Order" 
    xargs = "src_URL=http%3A%2F%2Fexample.com%2Frss%3Fid%3D123%26limit%3D40" />

It looks complex but if you remember that xargs is URL encoded and any other attribute is XML entity encoded you should be OK.

[edit] More Examples

[edit] Google Coop

An example "add this gadget to your webpage" code from google follows. Notice that it should be all on one line, but is presented here broken at each & for ease of viewing: 

<script src="http://gmodules.com/ig/ifr?
url=http://www.google.com/coop/api/008224879786263662799/cse/dlukhlm8-0m/gadget
&synd=open
&w=320
&h=75
&title=Appropedia's+Public+Domain+Search
&border=http%3A%2F%2Fgmodules.com%2Fig%2Fimages%2F
&output=js"></script>

We extract that information, to create: 

<widget
	type="googlegadget"
	url="http://www.google.com/coop/api/008224879786263662799/cse/dlukhlm8-0m/gadget"
	synd="open"
	width="320"
	height="75"
	title="Appropedia's Public Domain Search"
    border="http://gmodules.com/ig/images/" 
    output="js" />

Which produces:

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