Advanced Tutorial: Using the user meta field
In this tutorial, we will create a plugin that allows an admin to check the number of trades a user has made. Once checked, the plugin will store the timestamp of the last trade completed by the user in
meta
. The next time the plugin checks the user's trade amount, it will only count trades made after the user's stored trade timestamp.We will focus on the
script
section for this plugin.The user
meta
field is a JSON object in the User DB model that we can use to add additional fields for users. 'use strict';
const {
app,
loggerPlugin,
toolsLib
} = this.pluginLibraries;
const { query, validationResult } = require('express-validator');
const moment = require('moment');
const USER_META_FIELD_NAME = 'trade_count_plugin-latest_trade';
const init = async () => {
loggerPlugin.info(
'PLUGIN TRADE COUNT initializing...'
);
if (!toolsLib.getKitConfig().user_meta[USER_META_FIELD_NAME]) {
loggerPlugin.verbose(
'PLUGIN TRADE COUNT',
`User meta field ${USER_META_FIELD_NAME} not found. Creating field.`
);
await toolsLib.addKitUserMeta(
USER_META_FIELD_NAME,
'date-time',
'Last trade timestamp used for trade-count plugin',
false
);
}
loggerPlugin.info(
'PLUGIN TRADE COUNT initialized'
);
};
init()
.then(() => {
app.get(
'/plugins/trade-count/check',
[
toolsLib.security.verifyBearerTokenExpressMiddleware(['admin']),
query('user_id').isInt({ min: 1 }).toInt().optional()
],
async (req, res) => {
const errors = validationResult(req);
if (!errors.isEmpty()) {
return res.status(400).json({ errors: errors.array() });
}
const { user_id } = req.query;
loggerPlugin.verbose(
req.uuid,
'GET /plugins/trade-count/check auth',
req.auth.sub,
'user_id:',
user_id
);
try {
const user = await toolsLib.user.getUserByKitId(user_id, false);
if (!user) {
throw new Error('User not found');
}
const lastTradeTimestamp = user.meta[USER_META_FIELD_NAME];
const queryStartDate = toolsLib.isDatetime(lastTradeTimestamp)
? moment(lastTradeTimestamp).add(1, 'ms').toISOString()
: null;
loggerPlugin.verbose(
req.uuid,
'GET /plugins/trade-count/check',
'user last trade timestamp',
lastTradeTimestamp,
'trades query start date',
queryStartDate
);
const trades = await toolsLib.order.getAllUserTradesByKitId(
user.id,
null,
1,
1,
'timestamp',
'desc',
queryStartDate
);
loggerPlugin.verbose(
req.uuid,
'GET /plugins/trade-count/check',
'trade count',
trades.count
);
if (trades.count === 0) {
return res.json({
count: 0
});
}
const lastTrade = trades.data[0];
loggerPlugin.verbose(
req.uuid,
'GET /plugins/trade-count/check',
'last trade timestamp',
lastTrade.timestamp
);
await user.update({
meta: {
...user.meta,
[USER_META_FIELD_NAME]: lastTrade.timestamp
}
});
return res.json({
count: trades.count
});
} catch (err) {
loggerPlugin.error(
req.uuid,
'GET /plugins/trade-count/check err',
err.message
);
return res.status(400).json({ message: err.message });
}
}
);
})
.catch((err) => {
loggerPlugin.error(
'PLUGIN TRADE COUNT err during initialization',
err.message
);
});
const {
app,
loggerPlugin,
toolsLib
} = this.pluginLibraries;
const { query, validationResult } = require('express-validator');
const moment = require('moment');
First, import all the libraries that are required for this plugin.
const USER_META_FIELD_NAME = 'trade_count_plugin-latest_trade';
All user
meta
fields require a name. Here, we are calling the meta
field trade_count_plugin-latest_trade
. We recommend formatting meta
field names for plugins as <PLUGIN_NAME>-<FIELD_NAME>
const init = async () => {
loggerPlugin.info(
'PLUGIN TRADE COUNT initializing...'
);
if (!toolsLib.getKitConfig().user_meta[USER_META_FIELD_NAME]) {
loggerPlugin.verbose(
'PLUGIN TRADE COUNT',
`User meta field ${USER_META_FIELD_NAME} not found. Creating field.`
);
await toolsLib.addKitUserMeta(
USER_META_FIELD_NAME,
'date-time',
'Last trade timestamp used for trade-count plugin',
false
);
}
loggerPlugin.info(
'PLUGIN TRADE COUNT initialized'
);
};
init()
.then(() => {...})
.catch((err) => {
loggerPlugin.error(
'PLUGIN TRADE COUNT err during initialization',
err.message
);
});
Next, we create an
init
function that creates the new user meta
field if it doesn't already exist. All user meta
fields can be found in the Kit config object user_meta
. Each field in user_meta
has a type
, required
and description
value.// KIT CONFIG
{
...,
"user_meta": {
"trade_count_plugin-latest_trade": {
"type": "date-time",
"required": false,
"description": "Last trade timestamp used for trade-count plugin"
}
},
...
}
We are first checking if the user
meta
field exists in the Kit config returned from toolsLib.getKitConfig
. If not, we are creating the new field using the tools library function toolsLib.addKitUserMeta
. Please refer to the tools library documentation for more information regarding the tools library. Once initialized, the main script will be executed.app.get(
'/plugins/trade-count/check',
[
toolsLib.security.verifyBearerTokenExpressMiddleware(['admin']),
query('user_id').isInt({ min: 1 }).toInt().optional()
],
async (req, res) => {
const errors = validationResult(req);
if (!errors.isEmpty()) {
return res.status(400).json({ errors: errors.array() });
}
const { user_id } = req.query;
loggerPlugin.verbose(
req.uuid,
'GET /plugins/trade-count/check auth',
req.auth.sub,
'user_id:',
user_id
);
For this plugin, we need an endpoint
GET /plugins/trade-count/check
that returns the number of trades a user has made. try {
const user = await toolsLib.user.getUserByKitId(user_id, false);
if (!user) {
throw new Error('User not found');
}
const lastTradeTimestamp = user.meta[USER_META_FIELD_NAME];
const queryStartDate = toolsLib.isDatetime(lastTradeTimestamp)
? moment(lastTradeTimestamp).add(1, 'ms').toISOString()
: null;
loggerPlugin.verbose(
req.uuid,
'GET /plugins/trade-count/check',
'user last trade timestamp',
lastTradeTimestamp,
'trades query start date',
queryStartDate
);
const trades = await toolsLib.order.getAllUserTradesByKitId(
user.id,
null,
1,
1,
'timestamp',
'desc',
queryStartDate
);
loggerPlugin.verbose(
req.uuid,
'GET /plugins/trade-count/check',
'trade count',
trades.count
);
if (trades.count === 0) {
return res.json({
count: 0
});
}
const lastTrade = trades.data[0];
loggerPlugin.verbose(
req.uuid,
'GET /plugins/trade-count/check',
'last trade timestamp',
lastTrade.timestamp
);
await user.update({
meta: {
...user.meta,
[USER_META_FIELD_NAME]: lastTrade.timestamp
}
});
return res.json({
count: trades.count
});
} catch (err) {
loggerPlugin.error(
req.uuid,
'GET /plugins/trade-count/check err',
err.message
);
return res.status(400).json({ message: err.message });
}
We are first checking to see if a user with the given
user_id
exists. If so, we check to see if the user's meta.trade_count_plugin-latest_trade
value exists. If it doesn't that means we haven't checked the user's trade count using this plugin before. If it does, that means we have previously checked the user's trade count.Using the found
trade_count_plugin-latest_trade
value, we can determine which date to query the user's trades from. If trade_count_plugin-latest_trade
was null
, then we will query all of the user's trades.Once we get the trades response, we can read the number of trades made and the timestamp of the last trade completed. If the
count
is 0
, then we can just return 0
without updating the user's trade_count_plugin-latest_trade
value. Otherwise, we will get the latest trade's timestamp
, update the user's trade_count_plugin-latest_trade
value to that timestamp
, and return the count
. The next time we check the user's trade count, all trades starting from the updated trade_count_plugin-latest_trade
will be counted.