Тема: JS API: How to subscribe to Add/Remove Unit message
Hello! Session object has getItems() method, but how do I know that there was a change. I see that there is addListerner() but can't figure out where and how I should subscribe. Thanks!
1
13/09/2014 23:23:11JS API: How to subscribe to Add/Remove Unit message
- sergej.shirokov
- Gurtam Partner
- Неактивен
2
15/09/2014 09:37:07JS API: How to subscribe to Add/Remove Unit message
Re: JS API: How to subscribe to Add/Remove Unit message
Hi
Check Session.updateDataFlags function (its SDK JS wrapper around Remote API's core/update_data_flags request)
3
15/09/2014 10:10:31JS API: How to subscribe to Add/Remove Unit message
- sergej.shirokov
- Gurtam Partner
- Неактивен
Re: JS API: How to subscribe to Add/Remove Unit message
Could You please be more specific, which flags exactly I need? Here is my current code:
session = wialon.core.Session.getInstance();
session.updateDataFlags([
{
type: "type",
data: "avl_unit",
flags: wialon.item.Item.dataFlag.base | wialon.item.Unit.dataFlag.lastMessage,
mode: 0
}
], function(update_code) {
var items;
if (update_code) {
return;
}
items = session.getItems('avl_unit');
return console.log(items.length);
});
The problem is that the callback (where I call getItems()) is called only once. What I need is a notification when there was add/remove of an unit (for example: another admin just added a new unit for this user).
4
15/09/2014 11:16:51JS API: How to subscribe to Add/Remove Unit message
Re: JS API: How to subscribe to Add/Remove Unit message
Could You please be more specific, which flags exactly I need?
For create/delete base flag (0x1) is enought
What does Session.updateDataFlags do:
1. load items into Session (so you can get it session.getItems(...))
2. update items automaticaly (every 2 seconds SDK JS perform avl_events request, parse results and update correspondence items)
If you want to listen any item event (for example, itemDeleted) you should addListener for every item. You can find some items events examples on sdk.wialon.com (one of them sdk.wialon.com/playground)
If you're interested in itemCreated event you must addListener to your Session as follows
wialon.core.Session.getInstance().addListener("itemCreated", function () {
// itemCreated handler
}
5
16/09/2014 00:57:44JS API: How to subscribe to Add/Remove Unit message
- sergej.shirokov
- Gurtam Partner
- Неактивен
Re: JS API: How to subscribe to Add/Remove Unit message
wialon.core.Session.getInstance().addListener("itemCreated", function () {
// itemCreated handler
}Sorry, that doesn't work - function never called. Could you please try this approach by yourself on Wialon Local ?
I even added a button with click handler which calls session.getItems('avl_unit') and then traces to console number of items. Here is what I see:
a) if I delete an unit then clicking the button I see immediately decreased number - that correct!
b) but if I add a new unit then clicking the button shows no change, i.e. the same number of items as before unit addon - so my session don't see such kind "itemCreate" of event from server (which probably explains why there is no callback for the addListener).
For me it seems that "wialon.item.Item.dataFlag.base | wialon.item.Unit.dataFlag.lastMessage" is NOT enough to receive "item created" notifications from server.
6
16/09/2014 10:30:33JS API: How to subscribe to Add/Remove Unit message
Re: JS API: How to subscribe to Add/Remove Unit message
Sorry for confusing, but there is one more thing - by default, ItemsCreationChecking (method that trigger itemCreated event) run once in 10 minute, so i beleive you just havent wait enough to see it.
If you want to run check more often, you can do it manually calling following command
wialon.core.Session.getInstance().startItemsCreationChecking('avl_unit');We understand the problem with this event and will try to fix or refactor it soon.
7
16/09/2014 23:19:05JS API: How to subscribe to Add/Remove Unit message
- sergej.shirokov
- Gurtam Partner
- Неактивен
Re: JS API: How to subscribe to Add/Remove Unit message
Tried to wait more than 10 min - still no callback. On attempt to call startItemsCreationChecking (exactly as you suggested) I see following call stack in console:
Uncaught TypeError: undefined is not a function
MainViewModel.refresh mainViewModel.coffee:39
__bind mainViewModel.coffee:1
(anonymous function) mainViewModel.coffee:30
qx.Class.define.members.__dq wialon.js:9543
qx.Bootstrap.define.statics.create wialon.js:5325
qx.Class.define.members.__dC wialon.js:10040
qx.Class.define.members.__dy wialon.js:10005
qx.Bootstrap.define.statics.create wialon.js:5325
qx.Class.define.members.__dD wialon.js:10134
qx.Bootstrap.define.statics.create wialon.js:5325
8
17/09/2014 12:38:01JS API: How to subscribe to Add/Remove Unit message
Re: JS API: How to subscribe to Add/Remove Unit message
Sorry again, full example below (for Wialon Hosting, but should work on your Wialon Local too).
FYI we're refactoring "itemCreated" event system, so this code (with manual findNewItems calling) will be outdated soon. But old-style "itemCreated" listeners would work in any case.
Thanks for this topic, it helped to make SDK better 
<!DOCTYPE html>
<html>
<head>
<title>itemCreated event</title>
</head>
<body>
<!-- Button for manual item creation check -->
<input type="button" value="Run check" id="check"/>
<script type='text/javascript' src='https://hst-api.wialon.com/wsdk/script/wialon.js'></script>
<script type='text/javascript'>
// init session
wialon.core.Session.getInstance().initSession("https://hst-api.wialon.com");
// try to login
wialon.core.Session.getInstance().login("wialon_test", "test", "", function (code) {
if (code) {
console.log("Login failed");
} else {
console.log("Login success");
// Include mixin
qx.Class.include(wialon.core.Session, wialon.util.MDataFlagsHelper);
// Init creation checking procedure
wialon.core.Session.getInstance().startItemsCreationChecking("avl_unit");
// Add itemCreated event listener
wialon.core.Session.getInstance().addListener("itemCreated", function () {
// itemCreated handler
console.log("Created! ", arguments);
});
// Run checkItemCreation onclick
// use setTimeout here
document.getElementById("check").onclick = function () {
console.log("Trying to find new units..");
wialon.core.Session.getInstance().findNewItems("avl_unit");
};
}
});
</script>
</body>
</html>
9
17/09/2014 17:46:44JS API: How to subscribe to Add/Remove Unit message
(17/09/2014 17:48:16 отредактировано sergej.shirokov)- sergej.shirokov
- Gurtam Partner
- Неактивен
Re: JS API: How to subscribe to Add/Remove Unit message
Hallelujah, I just has received "itemCreated" callback!!! The key elements were:
1) qx.Class.include(wialon.core.Session, wialon.util.MDataFlagsHelper);
2) wialon.core.Session.getInstance().startItemsCreationChecking("avl_unit");
3) wialon.core.Session.getInstance().addListener("itemCreated", function () {
Thank You for cooperation!
10
17/09/2014 17:52:11JS API: How to subscribe to Add/Remove Unit message
- sergej.shirokov
- Gurtam Partner
- Неактивен
Re: JS API: How to subscribe to Add/Remove Unit message
Just quick follow up: Is it really necessary to do all the time the "wialon.core.Session.getInstance()", or it's quite legitimate to just store the instance in a class member (at constructor for instance) and then just use the member in all the code, callbacks and so on?
11
17/09/2014 19:15:10JS API: How to subscribe to Add/Remove Unit message
Re: JS API: How to subscribe to Add/Remove Unit message
sergej.shirokov пишет:
Just quick follow up: Is it really necessary to do all the time the "wialon.core.Session.getInstance()", or it's quite legitimate to just store the instance in a class member (at constructor for instance) and then just use the member in all the code, callbacks and so on?
I left full name for better example visibility, sure you can store instance in a variable and than use it where needed