expando

I have a db expando class called widget. I'm passing in a json string and converting it to a dict and then adding it to the datastore. My question is how can I loop through my dict to create dynamic fields. widget = Widget.get_by_key_name(key_name) widget.name = self.request.get('wname') fields = simplejson.loads(self.request.get('wcontents')) for k,v in fields.iteritems(): widget.k = v This renders "k" as my field name as oppose to the k value in the dict. The syntax widget.k references the attribute k on object widget . To dynamically choose which attribute you set, use the built-in setattr

Underneath the hood JQuery uses a map of "UUIDs" (just a counter it maintains as jQuery.uuid ) to work around the well-known memory leak issues browsers have when you attach a property to a tag in the DOM from Javascript. In lieu of doing so, JQuery uses the $.data(tag, name, value) to store data in a map keyed off of the uuid (a key that can be determined by checking tag[jQuery.expando] ). While $.data() is very useful, there are times you want to map data to tags without dumping that data into one global bucket - you want your own smaller bucket of data that you can, for example, check the

Regarding to jQuery utility function jQuery.data() the online documentation says: "The jQuery.data() method allows us to attach data of any type to DOM elements in a way that is safe from circular references and therefore from memory leaks. " Why to use: document.body.foo = 52; can result a memory leak -or in what conditions- so that I should use jQuery.data(document.body, 'foo', 52); Should I ALWAYS prefer .data() instead of using expandos in any case? (I would appreciate if you can provide an example to compare the differences) Thanks, burak ozdogan It's better precisely because of something

I'm developing code using jQuery and need to store data associated with certain DOM elements. There are a bunch of other questions about how to store arbitrary data with an html element, but I'm more interested in why I would pick one option over the other. Say, for the sake of extremely simplified argument, that I want to store a "lineNumber" property with each row in a table that is "interesting". Option 1 would be to just set an expando property on each DOM element (I hope I'm using the term 'expando' correctly): $('.interesting-line').each(function(i) { this.lineNumber = i; }); Option 2

Have been seeing the term "Expando" used recently with Dart. Sounds interesting. The API did not provide much of a clue to me. An example or two could be most helpful! (Not sure if this is related, but I am most anxious for a way to add methods (getters) and/or variables to a class. Hoping this might be a key to solving this problem. (hint: I am using the Nosuchmethod method now and want to be able to return the value of the unfound method.)) Thanks in advance, _swarmii John Evans Expandos allow you to associate objects to other objects. One very useful example of this is an HTML DOM element,

Is there any way in .net to bind a dictionary of properties to an instance at runtime, i.e., as if the base object class had a property like: public IDictionary Items { get; } I have come up with a solution involving a static dictionary and extension method void Main() { var x = new object(); x.Props().y = "hello"; } static class ExpandoExtension { static IDictionary<object, dynamic> props = new Dictionary<object, dynamic>(); public static dynamic Props(this object key) { dynamic o; if (!props.TryGetValue(key, out o)){ o = new ExpandoObject(); props[key] = o; } return o; } } but this stops the