[Ext Js] client-side sorting/column re-ordering issue

deltron0

i am using lightstreamer with an OverwriteTable to populate an extJS grid that has sorting and column re-ordering. when the grid is sorted or a column is moved, the grid stops receiving updates from lightstreamer. each cell in the grid is created as a <div> element with source, table, item and field attributes. using firebug, i see that this is converted into and id attribute with the following format: "F|table|item|field|div". i have tried moving the id along with the cell, but it appears that lightstreamer does not recognize the id or is using some other method to perform its updates.

i could use some help in restoring the association so that lightstreamer updates are reflected automatically.

Mone

Hello,

our library mantains a cache of pointers to the html tags. To let Lightstreamer update moved elements you should move the entire element not just the id.
Btw, if you are already using a non-lightstreamer grid it could be better if instead of an OverwriteTable you use a NonVisualTable.
It's the same approach taken on this demo where a Dojo Grid is used to display the data: http://www.lightstreamer.com/dojoDemo.htm- http://app.lightstreamer.com/DojoDemo

deltron0

so your library will keep track of elements moved within the dom? currently, i am setting the subscription info on a <div> that is created within a cell renderer. these elements are discarded when the column is moved or sorted. i will try to attach the subscription data to the <div> on level up, but i think i will have to dig into the ext js library to accomplish that.

in the interim, i will switch to using a NonVisualTable and updating the values directly.

thx

Mone

ok, let me know your progress or if you need further details.

deltron0

i haven't had much time to spend on moving to NonVisualTable, but i am getting an error (this.LS_gwJ has no properties lspushpage.js: Line 7)adding the table to the push page. the code is below. looking at the example that you cited, i think that my problem has something to do with passing null for group descriptor and schema or invoking createEngine instead of loadEngineMinimal (which doen't seem to be documented). what confuses me is that i can create an OverwriteTable with null group descriptor and schema.

//***** common *****
var lsPage = new PushPage();
var debugAlerts = false;
var remoteAlerts = true;
var pushHost = null;
lsPage.context.setDomain(domainName);
lsPage.context.setDebugAlertsOnClientError(debugAlerts);
lsPage.context.setRemoteAlertsOnClientError(remoteAlerts);

lsPage.onEngineCreation = function(lsEngine) {
	lightStreamerEngine = lsEngine;
				   
	lsEngine.context.setDebugAlertsOnClientError(debugAlerts);
	lsEngine.context.setRemoteAlertsOnClientError(remoteAlerts);
	lsEngine.connection.setLSHost(pushHost);
	lsEngine.connection.setLSPort(webServerPort);
	lsEngine.connection.setAdapterName(adapterName);
	lsEngine.policy.setMaxBandwidth(5);
	lsEngine.policy.setIdleTimeout(30000);
	lsEngine.policy.setPollingInterval(1000);
	lsEngine.changeStatus("STREAMING");
}

lsPage.bind();
lsPage.createEngine("SLEngine","ls/","SHARE_SESSION");
//***** common *****

function addPushTable(tableName, updateFnc, formatFnc) {
	var newTable = new OverwriteTable(null, null, "MERGE");
	newTable.setSnapshotRequired(true);
	newTable.setClearOnDisconnected(false); //default is false
	newTable.setClearOnRemove(false); //default is false
	newTable.onItemUpdate = updateFnc;
	newTable.onChangingValues = formatFnc;
	newTable.setPushedHtmlEnabled(false);
	lsPage.addTable(newTable, tableName);
}

function addNonVisualPushTable(tableName, updateFunction) {
	var newTable = new NonVisualTable(null, null, "MERGE");
	newTable.setSnapshotRequired(true);
	newTable.onItemUpdate = updateFunction;
	lsPage.addTable(newTable, tableName);
}

Mone

Hello,

loadEngineMinimal is no more documented as it was deprecated some time ago and is now completely removed from documentation even if the method is still in the code.

You can create an OverwriteTable passing null as group and schema because in that caseduring the addTable call the library checks the DOM to find associated elements and reads item and fields from there.
If you use a NonVisualTable there are no associated cells so that you must specify group and schema in the constructor.

Take a look to this example: http://www.lightstreamer.com/vb/showthread.php?t=49

Aldous11

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Thanks in advance!!!