Getting vk.com community members in seconds

dooza January 24, 2015 at 13:21

Getting vk.com community members in seconds

Tutorial

It's no secret that the VK API returns no more than 1,000 members in one request to the groups.getMembers method . In one second, you can get a maximum of 3,000 participants, because the limit on the number of requests per second is set to 3. This is solved by the execute method , with which you can get more than 100,000 participants in one second and up to 25,000 participants in one request . In this article I will tell you how I implemented it.

Without using the execute method , the process of getting members of a group with an audience of 4,000,000 people will take about 22 minutes, and we will need to complete about 4,000 API requests. Using the execute methodwe will speed up this process by about 40 seconds and complete only about 160 queries.

Content:

I. A little bit about execute
II. Javascript implementation
Sources and examples

I. A little bit about execute

This is a universal method that allows you to run a sequence of other methods, storing and filtering intermediate results.
A simple request is made like all other methods, but in the parameters you need to pass code written in VKScript .

What does VKScript support and what is it?

It is a language similar to JavaScript or ActionScript. The algorithm should end with the command return% expression%. Operators must be separated by semicolons.

The following are supported:

arithmetic operations
logical operations
creation of arrays and lists ([X, Y])
parseInt and parseDouble
concatenation (+)
if construct
array filter by parameter (@.)
API method calls, length parameter
loops using the while statement
Javascript methods: slice, push, pop, shift, unshift, splice, substr
delete operator
assignment to array elements, for example: row.user.action = "test";

Using this method, we can get the result of several methods in one API request.

II. Javascript implementation

We write a simple function that recurses will pull the procedure described below execute.getMembers.

getMembers(group_id);

To get the members of the group we will use execute , for one request we will get 25,000 members. Execute allows you to make up to 25 queries described using the VKScript language . In the code parameter, we need to pass the algorithm in the VKScript language .

The getMembers procedure has been created, which we will pull from the client 3 times per second.

var members = API.groups.getMembers({"group_id": Args.group_id, "v": "5.27", "sort": "id_asc", "count": "1000", "offset": Args.offset}).items; // делаем первый запрос и создаем массив
var offset = 1000; // это сдвиг по участникам группы
while (offset < 25000 && (offset + Args.offset) < Args.total_count) // пока не получили 20000 и не прошлись по всем участникам
{
  members = members + "," + API.groups.getMembers({"group_id": Args.group_id, "v": "5.27", "sort": "id_asc", "count": "1000", "offset": (Args.offset + offset)}).items; // сдвиг участников на offset + мощность массива
  offset = offset + 1000; // увеличиваем сдвиг на 1000
};
return members;