[OpenLayers-Dev] Metadata inside a JSON

[Matt Priour]

Toni,
I am assuming you are using an OpenLayers.Layer.Vector layer with an HTTP protocol.
You need to add a listener for 'beforefeaturesadded' event on the layer.
The original JSON should be cached in the event object as well as the parsed features.
You want to apply the layer configuration metadata properities to the layer in the 'beforefeaturesadded' event handler.
be sure to use 'beforefeaturesadded' with the plural featureS rather than the 'beforefeatureadded' event with the singular feature
The plural features event runs once before any features are added from each response, while the singular feature runs before each individual feature is added and the original JSON response will NOT be available. Also that is not a good place/time to be changing layer properties anyway.

Matt Priour
Kestrel Computer Consulting


IN REPLY TO:
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Date: Tue, 20 Jul 2010 17:31:14 +0200
From: toni hern?ndez <tonidelacalle at gmail.com>
Subject: [OpenLayers-Dev] Metadata inside a JSON

hi all,

I have a map with lots of layers. Each layer has its own style. The map
application gets each layer from a web-service that some else has developed
and can not be modified (I guess).

I thouht I could put any kind of data in a json file, so I tried this:

{
"type": "FeatureCollection",
"name": "Mapa de la Internacionalitat",
"minScale":"whatever",
"maxScale":"whatever",

//and then features and its properties?
"features": [
...
]
}

Now I have realized that atributes "name", "minScale" and "maxScale" are not
available from the layer object. I can only get the features properties.

Is it possible to read first the data of the layer, then create the layer
and finally add the features?
How could / should I do that?

Thanks in advance.
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