Available only in PRO Edition

Dynamic Loading

To load data dynamically from the server you can make use of the LazyDataProxy helper while loading data into dhtmlxGrid or dhtmlxList. This helper allows getting data partially, on demand, and rendering only those records that are in the visible area.

Read the related articles for detailed information about how to display large lists and tabular data efficiently:

• dynamic loading in Grid
• dynamic loading in List (You need to set the virtual:true property in the configuration object of List)

Initialize LazyDataProxy

Initialize LazyDataProxy with the dhx.LazyDataProxy object constructor. The constructor takes two parameters:

• url - (string) the URL which the component will use to load data after its initialization
• config - (object) a configuration object which contains parameters for loading data from the server

new dhx.LazyDataProxy("https://docs.dhtmlx.com/suite/backend/lazyload", {
    limit: 30,
    prepare: 5,
    delay: 150,
    from: 0
});

Parameters

There is a list of parameters that you can specify in the configuration object. All parameters are optional.

• from - (number) the index of the first data item to start loading from; default value: 0
• limit - (number) the count of records that should be loaded from the server during each dynamic loading request; default value: 50
• delay - (number) time interval (in milliseconds) to wait before the next dynamic loading request to the server (allows decreasing the number of server request during quick scrolling); default value: 50
• prepare - (number) the count of extra records that should be loaded from the server; default value: 0

Server-side Response

Server side will send the following data to the client side:

• data - (array) - the array of data records
• from - (number) - starting position in the data set to add the loaded data to
• total_count - (number) - the total number of records available on the server

data: [
    {country: "DR Congo", population: "84004989", yearlyChange: "0.0328"}
    {country: "Germany", population: "82293457", yearlyChange: "0.0022"}
    {country: "Iran", population: "82011735", yearlyChange: "0.0105"}
    {country: "Turkey", population: "81916871", yearlyChange: "0.0145"}
], 
total_count: 233,
from: 15

Updating URL

You can use the updateURL method to update the URL where the data will be loaded or to change parameters for loading data from the backend. The method takes two parameters:

• url - (string) the URL which the component will use to load data after its initialization. If not specified, the currently existing URL will be used.
• config - (object) a configuration object with parameters for loading data from the server. If not specified, clears parameters set earlier.

lazyDataProxy.updateURL("https://docs.dhtmlx.com/suite/backend/lazyload", {
    limit: 30,
    prepare: 5,
    delay: 150,
    from: 0
});

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