How to use web tracking SDK for JavaScript to collect website logs - Simple Log Service

If you want to collect and analyze information about website users, such as the browsers that are used by the users, their browsing behavior records, and their purchasing behavior records, you can use web tracking SDK for JavaScript to upload user logs to a Logstore. You can use web tracking SDK for JavaScript to upload logs directly from web pages to Simple Log Service, without the need to upload logs to an application server. This helps reduces server loads. This topic describes how to use web tracking SDK for JavaScript to collect website logs.

Prerequisites

The web tracking feature is enabled for your Logstore. For more information about how to enable and use the web tracking feature, see Use the web tracking feature to collect logs.

Limits

If you use web tracking SDK for JavaScript to upload website logs, you can write no more than 3 MB of log data or 4,096 logs at a time. For more information about web tracking SDK for JavaScript, see Web tracking SDK for JavaScript.

Step 1: Install and configure the SDK

npm method

Install Node.js.
Run the following code on your server to install dependencies:
```
npm install --save @aliyun-sls/web-track-browser
```

Add the following code to your program to configure the SDK:

import SlsTracker from '@aliyun-sls/web-track-browser'

const opts = {
  host: '${host}', // The Simple Log Service endpoint for the region where your project resides. Example: cn-hangzhou.log.aliyuncs.com.
  project: '${project}', // The name of the project. 
  logstore: '${logstore}', // The name of the Logstore. 
  time: 10, // The interval at which logs are sent. Default value: 10. Unit: seconds. 
  count: 10, // The maximum number of logs that can be sent in each request. Default value: 10. 
  topic: 'topic',// The custom topic of logs. 
  source: 'source',
  tags: {
    tags: 'tags',
  },
}

const tracker = new SlsTracker(opts)  // Create an SlsTracker object.

Parameter	Required	Description
host	Yes	The Simple Log Service endpoint for the region where your project resides. In this example, the Simple Log Service endpoint for the China (Hangzhou) region is used. Replace this parameter value with your actual endpoint. For more information, see Endpoints.
project	Yes	The name of the project.
logstore	Yes	The name of the Logstore.
time	No	The interval at which logs are sent. Default value: 10. Unit: seconds.
count	No	The maximum number of logs that can be sent in each request. Default value: 10.
topic	No	The topic of logs. You can specify a custom value to identify logs.
source	No	The source of logs. You can specify a custom value to identify logs.
tags	No	The tag information about logs. You can specify a custom value to identify logs.

CDN method

Add the following code to <body> of your HTML file. You can use Alibaba Cloud CDN to import the resource file of web tracking SDK for JavaScript. For more information about SDK versions, see Web tracking SDK for JavaScript.
```
<script src="https://g.alicdn.com/sls/sls-js-sdk/${SDK version}/web-track-browser.js"></script>
```

Add the following code to the JavaScript file of your website:

if (window.SLS_Tracker) {
       const tracker = new SLS_Tracker({
       host: '${host}', // The Simple Log Service endpoint for the region where your project resides. Example: cn-hangzhou.log.aliyuncs.com.
       project: '${project}', // The name of the project. 
       logstore: '${logstore}', // The name of the Logstore. 
       time: 10, // The interval at which logs are sent. Default value: 10. Unit: seconds. 
       count: 10, // The maximum number of logs that can be sent in each request. Default value: 10. 
       topic: 'topic',// The custom topic of logs. 
       source: 'source',
       tags: {
           tags: 'tags',
       },
    })
}

Parameter	Required	Description
host	Yes	The Simple Log Service endpoint for the region where your project resides. In this example, the Simple Log Service endpoint for the China (Hangzhou) region is used. Replace this parameter value with your actual endpoint. For more information, see Endpoints.
project	Yes	The name of the project.
logstore	Yes	The name of the Logstore.
time	No	The interval at which logs are sent. Default value: 10. Unit: seconds.
count	No	The maximum number of logs that can be sent in each request. Default value: 10.
topic	No	The topic of logs. You can specify a custom value to identify logs.
source	No	The source of logs. You can specify a custom value to identify logs.
tags	No	The tag information about logs. You can specify a custom value to identify logs.

Step 2: Upload logs

When you upload a single log, the log is uploaded as a separate object. When you upload multiple logs, the logs are uploaded as an array that contains multiple objects.

Upload a single log. The type is object. Example:

tracker.send({
  eventType:'view_product',
  productName: 'Tablet',
  price: 500
})

Immediately upload a single log. The time and count parameters do not take effect. The type is object. Example:
```
tracker.sendImmediate({
  eventType:'view_product',
  productName: 'Tablet',
  price: 500
})
```

Upload multiple logs at a time. The type is array. Example:

tracker.sendBatchLogs([
  {
    eventType: 'view_product',
    productName: 'Tablet',
    price: 500
  },
  {
    eventType: 'view_product',
    productName: 'Laptop',
    price: 1200
  }
])

Immediately upload multiple logs at a time. The time and count parameters do not take effect. The type is array. Example:

tracker.sendBatchLogsImmediate([
  {
    eventType:'view_product',
    productName: 'Tablet',
    price: 500
  },
  {
    eventType:'view_product',
    productName: 'Laptop',
    price: 1200
  }
])

Step 3: View the upload result

After logs are uploaded to a Logstore, you must create indexes to query and analyze the logs. For more information, see Create indexes.

Quick view

If no indexes are created, you can click Consumption Preview to quickly view logs. Then, you can query and analyze the logs. For more information, see Query and analyze logs.

Query and analyze logs

You can call the CreateIndex operation to create full-text indexes or field indexes. If you want to use the SELECT statement, you must create field indexes.
You can call the GetLogsV2 operation to query logs in a Logstore. The returned result is an array of logs. Each element in the array is a log.

What do I do if the "401 Authorization Required" error is reported when I debug code?

Before you use web tracking SDK for JavaScript to write logs to a Logstore, you must enable the web tracking feature for the Logstore. For more information, see Use the web tracking feature to collect logs.

References

If the response that is returned by Log Service contains error information after you call an API operation, the call fails. You can handle errors based on the error codes that are returned when API calls fail. For more information, see Error codes.
Alibaba Cloud OpenAPI Explorer provides debugging capabilities, SDKs, examples, and related documents. You can use OpenAPI Explorer to debug Log Service API operations without the need to manually encapsulate or sign requests. For more information, visit OpenAPI Portal.
Log Service provides the command-line interface (CLI) to meet the requirements for automated configurations in Log Service. For more information, see Log Service CLI.