loadURL does not support synchronous requests

[rdewit]

Since our Ajax class supports supports synchronous requests, it seems logical that loadURL should support that too. This patch provides that support. Since the list of parameters that are fed to the method are getting quite long, would it be an option to provide an {options} object?

P.S. Component 'Ajax' seems to be missing in the list (trac).

[crschmidt]

In general, loadURL is designed to be the minimal wrapper around Ajax.Request. If we add more options to it, we're just making it the same as Ajax.Request. Why not just use Ajax.Request?

[rdewit]

Replying to crschmidt:

In general, loadURL is designed to be the minimal wrapper around Ajax.Request. If we add more options to it, we're just making it the same as Ajax.Request. Why not just use Ajax.Request?

For advanced parsing of KML we will need to retrieve external URLs and will have to do that synchronised.

[crschmidt]

Right. So why aren't you using Ajax.Request?

(There is a right answer here, and if you get it, then we can open a ticket for addressing it. :))

[crschmidt]

(Btw, my previous comment isn't a test: I want to find out if the problem you're running into is the same one that I'm thinking of: if it isn't, then this ticket may have some value that I'm not seeing.)

[rdewit]

My reason for coming up with this whole thing was to have an easy 1 line way of fetching an external XML document (since the request will be done in several places in KML.js). The returned value would be the responseText.

Looking into it again and just having seen issue #964 where loadURL now returns the request object, this would be inconsistent behaviour. To be consistent, I would now need an extra line of code for fetching the request.transport.responseText anyway.

So, Chris, I will drop the issue and will be happy to have it marked as 'wontfix'. Still curious what you thought that I might have been thinking though. ;-)

[crschmidt]

            new OpenLayers.Ajax.Request("webprocessingserver/wps.cgi/" +
                                        type + ".geojson" + paramString,
                         {   method: 'post',
                             postBody: data,
                             onComplete: update,
                             requestHeaders: ['Content-type', 'application/json']
                          }
                         );

One line of JS to open an Ajax.Request -- which if set to synchronous, will return the content, I believe? In any case, I don't know that 'Easy, one-line way" really has any meaning, since it's just as easy with Ajax.Request as with loadURL based on my reading.

The bug that exists in Ajax.Request is that it doesn't take into account OpenLayers.ProxyHost -- which OpenLayers.loadURL does. We can likely fix this by moving the ProxyHost down a level. This is the only real thing that we should probably fix -- and if someone wants to 'own' that task, they should open a new ticket. :)