I want to scrape a website which uses LightStreamer for showing live data. How can i add an event handler to receive those messages in Javascript?
Unfortunately, LightStreamer doesn't have enough tutorial.
Following sample works for me:
var myEH = function ff(msg) {
console.log("message receieved.");
};
App.ls.getSubscriptions()[0].addListener({ onItemUpdate : myEH})
When i repalce "message receieved." with msg variable, i see a non-sense array which is not similar to what i see in Chrome DevTools (Network tab> ws section).
Also, there are isActive() and isSubscribed() method for each subscription. When i check them against array elements returned by getSubscriptions(), i see that all of them are true. But, in fact, Chrome DevTools shows that only one them that is active and receives message. Finding active subscription is another problem.
Update: Thanks #Robert for his help. Finally, i could understand that getSubscriptions()[6] includes what i need. Other subscriptions update clock or other things in page. I extracted items and fields from this subscription as following:
var myItems = App.ls.getSubscriptions()[6].getItems();
var myFields = App.ls.getSubscriptions()[6].getFields();
var myEH3 = function ff(msg) {
console.log('tttt3');
};
var mySub = new Subscription("MERGE", myItems, myFields);
mySub.addListener(myEH3);
App.ls.subscribe(mySub);
But this doesn't work. Server returns error 'Data Adapter Not found.' Changing to 'mySub.addListener({ onItemUpdate: myEH3});' does not help. I have already tried to add eventhandler directly to getSubscriptions()[6] via 'App.ls.getSubscriptions()[6].addListener({ onItemUpdate : myEH3});', but my function never called. Any Hint would be greatly apprecieated.
They have tutorial, and solid api documentation...
from
<script>
require(["LightstreamerClient", "Subscription", "StaticGrid"], function(LightstreamerClient, Subscription, StaticGrid) {
var client = new LightstreamerClient(null, "HELLOWORLD");
client.connect();
// you have to create your own SubscriptionListener
var grid = new StaticGrid("hellogrid", true);
var subscription = new Subscription("MERGE", grid.extractItemList(), grid.extractFieldList());
subscription.addListener(grid);
client.subscribe(subscription);
});
</script>
Now you have to create your own subscription listener according to follow interface. And then you have onItemUpdate on your subscription listener.
Finally, I could get my head around this library. Searching JavaScript files of webpage, I found that somewhere DataAdapter will be set to subscriptions.
This is my final code:
var myItems = App.ls.getSubscriptions()[6].getItems();
var myFields = App.ls.getSubscriptions()[6].getFields();
var adaptername = App.ls.getSubscriptions()[6].getDataAdapter();
var myEH3 = function ff(msg) {
console.log('message received.');
};
var mySub = new Subscription("MERGE", myItems, myFields);
mySub.setDataAdapter(adaptername);
mySub.setRequestedSnapshot("yes");
mySub.addListener({onItemUpdate: myEH3});
App.ls.subscribe(mySub);
Related
I've built an app that is form-based. I want to enable users to partially fill out a form, and then come back to it at a later date if they can't finish it at the present. I've used iron router to create a unique URL for each form instance, so they can come back to the link. My problem is that Meteor doesn't automatically save the values in the inputs, and the form comes up blank when it is revisited/refreshes. I tried the below solution to store the data in a temporary document in a separate Mongo collection called "NewScreen", and then reference that document every time the template is (re)rendered to auto fill the form. However, I keep getting an error that the element I'm trying to reference is "undefined". The weird thing is that sometimes it works, sometimes it doesn't. I've tried setting a recursive setTimeout function, but on the times it fails, that doesn't work either. Any insight would be greatly appreciated. Or, if I'm going about this all wrong, feel free to suggest a different approach:
Screens = new Meteor.Collection('screens') //where data will ultimately be stored
Forms = new Meteor.Collection('forms') //Meteor pulls form questions from here
NewScreen = new Meteor.Collection('newscreen') //temporary storage collection
Roles = new Meteor.Collection('roles'); //displays list of metadata about screens in a dashboard
//dynamic routing for unique instance of blank form
Router.route('/forms/:_id', {
name: 'BlankForm',
data: function(){
return NewScreen.findOne({_id: this.params._id});
}
});
//onRendered function to pull data from NewScreen collection (this is where I get the error)
Template.BlankForm.onRendered(function(){
var new_screen = NewScreen.findOne({_id: window.location.href.split('/')[window.location.href.split('/').length-1]})
function do_work(){
if(typeof new_screen === 'undefined'){
console.log('waiting...');
Meteor.setTimeout(do_work, 100);
}else{
$('input')[0].value = new_screen.first;
for(i=0;i<new_screen.answers.length;i++){
$('textarea')[i].value = new_screen.answers[i];
}
}
}
do_work();
});
//onChange event that updates the NewScreen document when user updates value of input in the form
'change [id="on-change"]': function(e, tmpl){
var screen_data = [];
var name = $('input')[0].value;
for(i=0; i<$('textarea').length;i++){
screen_data.push($('textarea')[i].value);
}
Session.set("updateNewScreen", this._id);
NewScreen.update(
Session.get("updateNewScreen"),
{$set:
{
answers: screen_data,
first: name
}
});
console.log(screen_data);
}
If you get undefined that could mean findOne() did not find the newscreen with the Id that was passed in from the url. To investigate this, add an extra line like console.log(window.location.href.split('/')[window.location.href.split('/').length-1], JSON.stringify(new_screen));
This will give you both the Id from the url and the new_screen that was found.
I would recommend using Router.current().location.get().path instead of window.location.href since you use IR.
And if you're looking for two way binding in the client, have a look at Viewmodel for Meteor.
Here is my scenario. The page loads and the map loads with an empty vector layer. So its there, but has no features. Then the user clicks a button and a CQL filter loads features according to the CQL settings.
My methodology to implement this. I set an empty vector layer, no loader or strategy. The button the user clicks for the first time calls a "initialization " function (=firstTimeOnly()) that:
sets a loader and a strategy to the vector layer
now that a loader exists, calls another "filtering" function (=changeFilter()) that
resets the loader's cql filter and loads features
now the "filtering" function gets attached to the button and called
with every click. The "initialization" function served its purpose
and detaches itself from the button.
Here is my code
<button id= "magicButton", onclick="firstTimeOnly()">Click me</button>
//set globals to use them
var cqlFilter = "name='testpoint9'";
var urlTemplate = 'http://localhost:5550/geoserver/mymap/wfs?service=WFS&version=1.0.0&request=GetFeature&typeName=mymap:layerName&CQL_FILTER={{CQLFILTER}}&outputFormat=application/json';
var loader = function (extent) {
var url = urlTemplate.replace('{{CQLFILTER}}', cqlFilter);
$.ajax(url, {
type: 'GET',
success: function(response) {
var res = response;
var geojsonFormat = new ol.format.GeoJSON();
sourceVector.addFeatures(geojsonFormat.readFeatures(response));
}
})
};
var strategy = new ol.loadingstrategy.tile(ol.tilegrid.createXYZ({maxZoom: 20}));
//empty vector source
var sourceVector = new ol.source.Vector({});
function changeFilter() {
//remove all, set cql and reload
var featsToRemove = layerVector.getSource().getFeatures();
for (var f=0;f<featsToRemove.length;f++)
{
layerVector.getSource().removeFeature(featsToRemove[f]);
}
cqlFilter = "name LIKE 'p'";
sourceVector.clear(true);
}
layerVector = new ol.layer.Vector({
source: sourceVector,
style:styleFunction
});
function firstTimeOnly() {
sourceVector.set('loader', loader);
sourceVector.set('strategy', strategy);
changeFilter();
document.getElementById("magicButton").removeEventListener("click", firstTimeOnly, false);
document.getElementById("magicButton").addEventListener("click", changeFilter, false);
}
This is based to erilem's code for cql filter resetting and if I use just his code works fine. But if I want to start with an empty layer and edit it as the above, I get nothing. My code gives no errors. But, if I click the button I get nothing.
Please advide me how to fix this. Or maybe its an overkill and you suggest something smarter.
Thanks
UPDATE
If I put
console.log("loader "+sourceVector.get('loader'));
at the end of the changeFilter I get the loader function. So, I guess the first time I click the button, the firstTimeOnly actually sets a loader and calls changeFilter. So, the loader is there, but does not work? Any help?
Without getting into potential issues with Openlayers the issue I see is that removeEventListener only works for removing listeners that were set with addEventListener. Since you bound the onclick declaratively in the HTML the way to unbind it would be by doing document.getElementById("magicButton").onclick = null.
That said I would change your example so that somewhere in your code you set the event listener using addEventListener.
Example:
function firstTimeOnly() {
sourceVector.set('loader', loader);
sourceVector.set('strategy', strategy);
changeFilter();
document.getElementById("magicButton").removeEventListener("click", firstTimeOnly, false);
document.getElementById("magicButton").addEventListener("click", changeFilter, false);
}
document.getElementById("magicButton").addEventListener("click", firstTimeOnly, false);
And get rid of the onclick in the HTML.
Also consider caching the reference to magicButton so that you don't have to be constantly calling getElementById.
var magicButton = document.getElementById("magicButton");
Extending a Google Spreadsheet, I run a script showing some data in a sidebar. At the bottom I want to add a button to mail the data.
However I can't figure out how the data can be passed from button to handler:
There's no possibility to pass data into the event call;
There's no way to get the button object from the event info, I can merely get the ID, which is useless if I can't get to the uiInstance (created outside of the handler function).
So what's the trick?
You have to add a callback element (possibly a panel wrapping everything you need) to the server handler before assigning it to the button. For example:
function myFunction() {
var app = UiApp.createApplication();
var panel = app.createVerticalPanel();
panel.setId('myPanel').add(
app.createTextBox().setName('boxExample')).add(
app.createListBox().setName('listExample').addItem('A').addItem('B'));
// ↓↓ this is what you need ↓↓
var handler = app.createServerHandler('callbackFunction').addCallbackElement(panel);
var btn = app.createButton(btn, handler);
app.add(panel.add(btn));
//show app...
}
function callbackFunction(e) {
var app = UiApp.getActiveApplication();
app.getElementById('myPanel').add(
app.createLabel(e.parameter.boxExample)).add(
app.createLabel(e.parameter['listExample']));
return app;
}
Using PropertiesService
I found (I don't know how) Google Script offers a data storage service called PropertiesService.
Assuming, as in this case, the data is for user only, I would need to first store the data as such:
var userProperties = PropertiesService.getUserProperties()
userProperties.setProperty("myKey", "myValue")
// Note myValue will be a string, so to store an array,
// you'd need JSON.stringify(myArray)
Then as the button handler is called, the script can retrieve the data easily:
var userProperties = PropertiesService.getUserProperties()
var myValue = userProperties.getProperty("myKey")
Using Hidden Widget
An alternative seems to be the use of a "hidden" widget.
function doGet() {
var app = UiApp.createApplication();
// Note that the name "appState" for callbacks, and the id "hidden" for
// getting a reference to the widget, are not required to be the same.
var hidden = app.createHidden("appState", "0").setId("hidden");
app.add(hidden);
var handler = app.createServerHandler("click").addCallbackElement(hidden);
app.add(app.createButton("click me!", handler));
app.add(app.createLabel("clicked 0 times").setId("label"));
return app;
}
function click(eventInfo) {
var app = UiApp.createApplication();
// We have the value of the hidden field because it was a callback element.
var numClicks = Number(eventInfo.parameter.appState);
numClicks++;
// Just store the number as a string. We could actually store arbitrarily complex data
// here using JSON.stringify() to turn a JavaScript object into a string to store, and
// JSON.parse() to turn the string back into an object.
app.getElementById("hidden").setValue(String(numClicks));
app.getElementById("label").setText("clicked " + numClicks + " times");
return app;
}
(code from linked reference)
Im trying to run this cloud code every time a new object gets saved to my class called "Message", however i believe i am calling the afterSave method incorrectly because not even my console.log is showing up after i save a new object to my class called "Message". What is wrong with my code?
Parse.Cloud.afterSave("sendMessage", function(Message, response) {
var messageBody = null;
var messageSenderName = null;
var messageSenderId = null;
var randUsers = [];
console.log("The variables were set");
............other code that doesn't matter................
});
As far as I see, you want to fire up a cloud function whenever new entry is saved to Parse DB.
For this scenario afterSave is the way to go. However, your function declaration is wrong. The function must be in the format;
Parse.Cloud.afterSave("Message", function(request) {
.....
}
where the request contains the currently saved entry information.Hope this helps.Regards.
Is there a way to get the ScriptNode that initiated a state in an Activiti workflow in Alfresco? I have a ScriptTask in my workflow, and it has a Alfresco Script Listener set up for the Start event. When the script is called, I'd like the ScriptNode that transitioned into the ScriptTask in the workflow to be passed as a parameter to the function defined as the listener. Is that possible?
Editing for clarity:
Here's a screenshot of Eclispe with the Activiti plugin.
http://i.imgur.com/DAKtq.jpg
This workflow gets started by another workflow with webscripts.
var props = new Object();
var dd = new Date();
props[EL_PROP_WORK_UNIT_NAME] = "testNode" + DateISOString( dd );
props[EL_PROP_WORK_UNIT_SOURCE_CODE] = "ROB";
props[EL_PROP_WORK_UNIT_DELIVERY_DATE] = dd;
node = getHome().createNode(name, EL_TYPE_WORK_UNIT, props);
var EL_WORKFLOW = "activiti$The-workflow";
var activeWfs = node.activeWorkflows;
if( activeWfs === null || activeWfs.length === 0 )
{
var workflowPackage = workflow.createPackage();
workflowPackage.addNode( node );
var workflowDef = workflow.getDefinitionByName(EL_WORKFLOW);
var workflowPath = workflowDef.startWorkflow( workflowPackage, new Object());
}
So the listener calls another javascript method...
function artPDFRename()
{
logger.log("==============================");
logger.log("<START> artPDFRename");
var workflowDef = workflow.getDefinitionByName(EL_WORKFLOW);
var activeInstance = workflowDef.getActiveInstances();
// ????
}
The goal is to have this handling be automatic. We're trying to design this with as little of manual intervention as possible, and are not assigning tasks to users to perform. Yes, there's probably another way to rename a PDF file, but I can't seem to figure out from the documentation listed here how to get a pointer to the node I put in the bpm_package object. That's the question.
Or am I so far off base on how we're developing this that it makes no sense?
As an example check the ScriptTaskListener class. Here all the workflow variables are put in a map.
The following code is interesting:
// Add all workflow variables to model
Map variables = delegateTask.getExecution().getVariables();
for (Entry<String, Object> varEntry : variables.entrySet())
{
scriptModel.put(varEntry.getKey(), varEntry.getValue());
}
So with this you could use bpm_package as an object within your script within the workflow script task.
So if you need the node were the workflow has run on, the following code should work (where task is your delegateTask from your notify method of the Listener:
delegateTask.getVariable("bpm_package");
// or like the example above
delegateTask.getExecution().getVariable("bpm_package");
This will be a list so take the first one and that will be your node.
---------update
If you're using the javascript from alfresco then you can directly use the parent object bpm_package.
So in your case it would be best to do the following:
var node = bpm_package.children[0]; //or you could check if the
package isn't null
// Then send the node into your
artPDFRename(node); //or you could just add the bpm_package code in
your js file