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Adding support for chaining processes.

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This commit is contained in:
ahocevar
2012-08-09 18:28:53 +02:00
parent c64621f510
commit ec9ab8129e
2 changed files with 280 additions and 46 deletions
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19
examples/wps-client.js
View File

@@ -1,6 +1,6 @@
OpenLayers.ProxyHost = 'proxy.cgi?url=';
var map, client, process;
var map, client, intersect, buffer;
function init() {
@@ -23,18 +23,27 @@ function init() {
client = new OpenLayers.WPSClient({
servers: {
local: "http://demo.opengeo.org/geoserver/wps"
opengeo: 'http://demo.opengeo.org/geoserver/wps'
}
});
// Create a process and execute it
process = client.getProcess("local", "JTS:intersection");
process.execute({
// Create a process and configure it
intersect = client.getProcess('opengeo', 'JTS:intersection');
intersect.configure({
// spatial input can be a feature or a geometry or an array of
// features or geometries
inputs: {
a: features,
b: geometry
}
});
// Create another process which chains the previous one and execute it
buffer = client.getProcess('opengeo', 'JTS:buffer');
buffer.execute({
inputs: {
geom: intersect.output(),
distance: 1
},
success: function(outputs) {
// outputs.result is a feature or an array of features for spatial

293
lib/OpenLayers/WPSProcess.js
View File

@@ -14,7 +14,7 @@
*/
/**
* Class: OpenLayers.WPSProces
* Class: OpenLayers.WPSProcess
*/
OpenLayers.WPSProcess = OpenLayers.Class({
@@ -23,7 +23,8 @@ OpenLayers.WPSProcess = OpenLayers.Class({
* {<OpenLayers.Events>}
*
* Supported event types:
* describeprocess - fires when the process description is available
* describeprocess - Fires when the process description is available for
* the first time.
*/
events: null,
@@ -57,6 +58,20 @@ OpenLayers.WPSProcess = OpenLayers.Class({
*/
formats: null,
/**
* Property: chained
* {Integer} Number of chained processes for pending execute reqeusts that
* don't have a full configuration yet.
*/
chained: 0,
/**
* Property: executeCallbacks
* {Array} Callbacks waiting to be executed until all chained processes
* are configured;
*/
executeCallbacks: null,
/**
* Constructor: OpenLayers.WPSProcess
*
@@ -74,6 +89,7 @@ OpenLayers.WPSProcess = OpenLayers.Class({
OpenLayers.Util.extend(this, options);
this.events = new OpenLayers.Events(this);
this.executeCallbacks = [];
this.formats = {
'application/wkt': new OpenLayers.Format.WKT(),
@@ -86,17 +102,38 @@ OpenLayers.WPSProcess = OpenLayers.Class({
* Issues a DescribeProcess request asynchronously and fires the
* 'describeprocess' event as soon as the response is available in
* <description>.
*
* Parameters:
* options - {Object} Coniguration for the method call
*
* Available options:
* callback - {Function} Callback to execute when the description is
* available. Will be called with the parsed description as argument.
* Optional.
* scope - {Object} The scope in which the callback will be executed.
* Default is the global object.
*/
describe: function() {
describe: function(options) {
options = options || {};
function callback() {
if (options.callback) {
window.setTimeout(function() {
options.callback.call(options.scope, this.description);
}, 0);
}
}
var server = this.client.servers[this.server];
if (this.description !== null) {
callback();
return;
} else if (server.describeProcessResponse[this.identifier] === null) {
// pending request
this.events.register('describeprocess', this, callback);
return;
} else if (this.identifier in server.describeProcessResponse) {
// process description already cached on client
this.parseDescription();
callback();
return;
}
// set to null so we know a describeFeature request is pending
@@ -109,14 +146,21 @@ OpenLayers.WPSProcess = OpenLayers.Class({
REQUEST: 'DescribeProcess',
IDENTIFIER: this.identifier
},
success: this.parseDescription,
success: function(response) {
this.parseDescription(response);
if (options.callback) {
options.callback.call(options.scope, this.description);
}
},
scope: this
});
},
/**
* APIMethod: execute
* Executes the process
* APIMethod: configure
* Configure the process, but do not execute it. Use this for processes
* that are chained as input of a different process by means of the
* <output> method.
*
* Parameters:
* options - {Object}
@@ -126,20 +170,18 @@ OpenLayers.WPSProcess = OpenLayers.Class({
* For spatial data inputs, the value of an input is usually an
* <OpenLayers.Geometry>, an <OpenLayers.Feature.Vector> or an array of
* geometries or features.
* success - {Function} Callback to call when the process is complete.
* This function is called with an outputs object as argument, which
* will have a 'result' property. For processes that generate spatial
* output, this will either be a single <OpenLayers.Feature.Vector> or
* an array of features.
* scope - {Object} Optional scope for the success callback.
* callback - {Function} Callback to call when the configuration is
* complete. Optional.
* scope - {Object} Optional scope for the callback.
*/
execute: function(options) {
configure: function(options) {
if (!this.description) {
this.events.register('describeprocess', this, function execute() {
this.events.unregister('describeprocess', this, execute);
this.execute(options);
this.describe({
callback: function() {
this.configure(options);
},
scope: this
});
this.describe();
return;
}
var description = this.description,
@@ -149,26 +191,105 @@ OpenLayers.WPSProcess = OpenLayers.Class({
input = description.dataInputs[i];
this.setInputData(input, inputs[input.identifier]);
}
//TODO For now we only handle responseForm with a single output
this.setResponseForm();
if (options.callback) {
options.callback.call(options.scope);
}
},
/**
* APIMethod: execute
* Configures and executes the process
*
* Parameters:
* options - {Object}
*
* Available options:
* inputs - {Object} The inputs for the process, keyed by input identifier.
* For spatial data inputs, the value of an input is usually an
* <OpenLayers.Geometry>, an <OpenLayers.Feature.Vector> or an array of
* geometries or features.
* output - {String} The identifier of an output to parse. Optional. If not
* provided, the first output will be parsed.
* success - {Function} Callback to call when the process is complete.
* This function is called with an outputs object as argument, which
* will have a 'result' property. For processes that generate spatial
* output, this will either be a single <OpenLayers.Feature.Vector> or
* an array of features.
* scope - {Object} Optional scope for the success callback.
*/
execute: function(options) {
this.configure({
inputs: options.inputs,
callback: function() {
var me = this;
//TODO For now we only deal with a single output
var output = this.getOutputIndex(
me.description.processOutputs, options.output
);
me.setResponseForm({outputIndex: output});
(function callback() {
OpenLayers.Util.removeItem(me.executeCallbacks, callback);
if (me.chained !== 0) {
me.executeCallbacks.push(callback);
return;
}
OpenLayers.Request.POST({
url: this.client.servers[this.server].url,
data: new OpenLayers.Format.WPSExecute().write(this.description),
url: me.client.servers[me.server].url,
data: new OpenLayers.Format.WPSExecute().write(me.description),
success: function(response) {
var mimeType = this.findMimeType(this.description.processOutputs[0].complexOutput);
var features = this.formats[mimeType].read(response.responseText);
var mimeType = me.findMimeType(
me.description.processOutputs[output].complexOutput.supported.formats
);
//TODO For now we assume a spatial output
var features = me.formats[mimeType].read(response.responseText);
if (options.success) {
options.success.call(options.scope, {
result: features
});
}
},
scope: me
});
})();
},
scope: this
});
},
/**
* APIMethod: output
* Chain an output of a configured process (see <configure>) as input to
* another process.
*
* (code)
* intersect = client.getProcess('opengeo', 'JTS:intersection');
* intersect.configure({
* // ...
* });
* buffer = client.getProcess('opengeo', 'JTS:buffer');
* buffer.execute({
* inputs: {
* geom: intersect.output(), // <-- here we're chaining
* distance: 1
* },
* // ...
* });
* (end)
*
* Parameters:
* identifier - {String} Identifier of the output that we're chaining. If
* not provided, the first output will be used.
*/
output: function(identifier) {
return new OpenLayers.WPSProcess.ChainLink({
process: this,
output: identifier
});
},
/**
* Method: parseDescription
* Parses the DescribeProcess response
*
* Parameters:
* response - {Object}
@@ -197,15 +318,37 @@ OpenLayers.WPSProcess = OpenLayers.Class({
*/
setInputData: function(input, data) {
// clear any previous data
delete input.data;
delete input.reference;
if (data instanceof OpenLayers.WPSProcess.ChainLink) {
++this.chained;
input.reference = {
method: 'POST',
href: data.process.server === this.server ?
//TODO what about implementations other than GeoServer?
'http://geoserver/wps' :
this.client.servers[data.process.server].url
};
data.process.describe({
callback: function() {
--this.chained;
this.chainProcess(input, data);
},
scope: this
});
} else {
input.data = {};
if (data) {
var complexData = input.complexData;
if (complexData) {
var format = this.findMimeType(complexData);
var format = this.findMimeType(complexData.supported.formats);
input.data.complexData = {
mimeType: format,
value: this.formats[format].write(this.toFeatures(data))
};
} else {
input.data.literalData = {
value: data
};
}
}
},
@@ -213,17 +356,81 @@ OpenLayers.WPSProcess = OpenLayers.Class({
/**
* Method: setResponseForm
* Sets the responseForm property of the <execute> payload.
*
* Parameters:
* options - {Object} See below.
*
* Available options:
* outputIndex - {Integer} The index of the output to use. Optional.
* supportedFormats - {Object} Object with supported mime types as key,
* and true as value for supported types. Optional.
*/
setResponseForm: function() {
output = this.description.processOutputs[0];
setResponseForm: function(options) {
options = options || {};
output = this.description.processOutputs[options.outputIndex || 0];
this.description.responseForm = {
rawDataOutput: {
identifier: output.identifier,
mimeType: this.findMimeType(output.complexOutput)
mimeType: this.findMimeType(output.complexOutput.supported.formats, options.supportedFormats)
}
};
},
/**
* Method: getOutputIndex
* Gets the index of a processOutput by its identifier
*
* Parameters:
* outputs - {Array} The processOutputs array to look at
* identifier - {String} The identifier of the output
*
* Returns
* {Integer} The index of the processOutput with the provided identifier
* in the outputs array.
*/
getOutputIndex: function(outputs, identifier) {
var output;
if (identifier) {
for (var i=outputs.length-1; i>=0; --i) {
if (outputs[i].identifier === identifier) {
output = i;
break;
}
}
} else {
output = 0;
}
return output;
},
/**
* Method: chainProcess
* Sets a fully configured chained process as input for this process.
*
* Parameters:
* input - {Object} The dataInput that the chained process provides.
* chainLink - {<OpenLayers.WPSProcess.ChainLink} The process to chain.
*/
chainProcess: function(input, chainLink) {
var output = this.getOutputIndex(
chainLink.process.description.processOutputs, chainLink.output
);
input.reference.mimeType = this.findMimeType(
input.complexData.supported.formats,
chainLink.process.description.processOutputs[output].complexOutput.supported.formats
);
var formats = {};
formats[input.reference.mimeType] = true;
chainLink.process.setResponseForm({
outputIndex: output,
supportedFormats: formats
});
input.reference.body = chainLink.process.description;
while (this.executeCallbacks.length > 0) {
this.executeCallbacks[0]();
}
},
/**
* Method: toFeatures
* Converts spatial input into features so it can be processed by
@@ -256,16 +463,19 @@ OpenLayers.WPSProcess = OpenLayers.Class({
* Finds a supported mime type.
*
* Parameters:
* complex - {Object} A complexData or complexOutput object from the
* process description.
* sourceFormats - {Object} An object literal with mime types as key and
* true as value for supported formats.
* targetFormats - {Object} Like <sourceFormats>, but optional to check for
* supported mime types on a different target than this process.
* Default is to check against this process's supported formats.
*
* Returns:
* {String} A supported mime type.
*/
findMimeType: function(complex) {
var formats = complex.supported.formats;
for (var f in formats) {
if (f in this.formats) {
findMimeType: function(sourceFormats, targetFormats) {
targetFormats = targetFormats || this.formats;
for (var f in sourceFormats) {
if (f in targetFormats) {
return f;
}
}
@@ -274,3 +484,18 @@ OpenLayers.WPSProcess = OpenLayers.Class({
CLASS_NAME: "OpenLayers.WPSProcess"
});
/**
* Class: OpenLayers.WPSProcess.ChainLink
*/
OpenLayers.WPSProcess.ChainLink = OpenLayers.Class({
process: null,
output: null,
initialize: function(options) {
OpenLayers.Util.extend(this, options);
}
});