convert binary 16 id to 36 character uuid in juggler models - mysql

Question

Here is my question in brief:
I am using StrongLoop to work with an existing MySQL database. The database uses binary 16 datatypes to store primary keys and foreign keys. When I create the models using Strongloop tools, the data is sent to the client as string arrays in the JSON. I would like the JSON to contain the converted 36 character string. In the database, I have bintouuid and uuidtobin functions that will convert the data to/from the 36 character format. Can anyone provide the code I would use in the model or REST services to extend it to convert the arrays (or binary data) into the needed string format?
Here are details around the scenario:
The table script looks like this:
CREATE TABLE `alert` (
`ID` binary(16) NOT NULL,
`Subject` varchar(255),
`Text` text NOT NULL,
`Read` int(11) DEFAULT '0',
`AddedDate` timestamp NULL DEFAULT NULL,
`LastUpdated` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
`IsDeleted` bit(1) NOT NULL DEFAULT b'0',
PRIMARY KEY (`ID`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1
I have functions for creating and converting uuids to/from binary format:
newUuidToBin()
CREATE DEFINER=`root`#`localhost` FUNCTION `newuuidtobin`() RETURNS binary(16)
BEGIN
DECLARE UUID char(37);
SET UUID = UUID();
RETURN uuidtobin(UUID);
END
uuidToBin(UUID char(36))
CREATE DEFINER=`root`#`localhost` FUNCTION `uuidtobin`(UUID char(36)) RETURNS binary(16)
BEGIN
RETURN CONCAT(UNHEX(LEFT(UUID,8)),UNHEX(MID(UUID,10,4)),UNHEX(MID(UUID,15,4)),UNHEX(MID(UUID,20,4)),UNHEX(RIGHT(UUID,12)));
END
binToUuid(UUID BINARY(16))
CREATE DEFINER=`root`#`localhost` FUNCTION `bintouuid`(UUID BINARY(16)) RETURNS char(36) CHARSET utf8
BEGIN
RETURN concat(HEX(LEFT(uuid,4)),'-', HEX(MID(uuid,5,2)),'-', HEX(MID(uuid,7,2)),'-',HEX(MID(uuid,9,2)),'-',HEX(RIGHT(uuid,6)));
END
I have a trigger that creates the binary uuid when a record is created:
CREATE TRIGGER before_insert_alert
BEFORE INSERT
ON road.alert
FOR EACH ROW
SET new.id = newuuidtobin();
My default Alert.json for the model looks like this:
{
"name": "Alert",
"base": "PersistedModel",
"idInjection": false,
"mysql": {
"schema": "messaging",
"table": "alert"
},
"properties": {
"id": {
"type": "Binary",
"id": true,
"required": true,
"length": 16,
"precision": null,
"scale": null,
"mysql": {
"columnName": "ID",
"dataType": "binary",
"dataLength": 16,
"dataPrecision": null,
"dataScale": null,
"nullable": "N"
},
"_selectable": false
},
"subject": {
"type": "String",
"required": false,
"length": 65535,
"precision": null,
"scale": null,
"mysql": {
"columnName": "Subject",
"dataType": "text",
"dataLength": 65535,
"dataPrecision": null,
"dataScale": null,
"nullable": "Y"
},
"_selectable": true
},
"text": {
"type": "String",
"required": true,
"length": 255,
"precision": null,
"scale": null,
"mysql": {
"columnName": "Text",
"dataType": "varchar",
"dataLength": 255,
"dataPrecision": null,
"dataScale": null,
"nullable": "N"
},
"_selectable": false
},
"read": {
"type": "Number",
"required": false,
"length": null,
"precision": 10,
"scale": 0,
"mysql": {
"columnName": "Read",
"dataType": "int",
"dataLength": null,
"dataPrecision": 10,
"dataScale": 0,
"nullable": "Y"
},
"_selectable": true
},
"addeddate": {
"type": "Date",
"required": false,
"length": null,
"precision": null,
"scale": null,
"mysql": {
"columnName": "AddedDate",
"dataType": "timestamp",
"dataLength": null,
"dataPrecision": null,
"dataScale": null,
"nullable": "Y"
},
"_selectable": true
},
"lastupdated": {
"type": "Date",
"required": true,
"length": null,
"precision": null,
"scale": null,
"mysql": {
"columnName": "LastUpdated",
"dataType": "timestamp",
"dataLength": null,
"dataPrecision": null,
"dataScale": null,
"nullable": "N"
},
"_selectable": false
},
"isdeleted": {
"type": "Binary",
"required": true,
"length": null,
"precision": 1,
"scale": null,
"mysql": {
"columnName": "IsDeleted",
"dataType": "bit",
"dataLength": null,
"dataPrecision": 1,
"dataScale": null,
"nullable": "N"
},
"_selectable": false
}
},
"validations": [],
"relations": {},
"acls": [],
"methods": []
}
When accessing the REST endpoint with a get,
http://localhost:3000/api/Alerts
...I get this result. Note: the id comes back in the form of an array.
[
{
"id": [
97,
55,
50,
102,
52,
49,
50,
48,
45,
57,
53,
54,
97,
45,
49,
49
],
"subject": "uuids",
"text": "my message",
"read": 0,
"addeddate": null,
"lastupdated": "2015-01-05T23:10:03.000Z",
"isdeleted": [
0
]
},
.
.
.
]
...but I want the result to look like this:
[
{
"id": "C39BC3A2-381F-5568-11C3-A0C2B66E64EF"
"subject": "uuids",
"text": "my message",
"read": 0,
"addeddate": null,
"lastupdated": "2015-01-05T23:10:03.000Z",
"isdeleted": [
0
]
},
.
.
.
]
On update, the REST endpoint should convert the string using the mysql function:
update alert set `read` = 1 where id = uuidtobin('C39BC3A2-381F-5568-11C3-A0C2B66E64EF');
How would I extend the model to use the mysql functions to select data showing the ids as uuid strings in the json result, and update records using the uuid 36 character string?

Answer 1

You can use a remote hook to manipulate the response before sending it back. See http://docs.strongloop.com/display/LB/Remote+hooks
Another possible solution is using model hooks to modify the data before/after saving it. See http://docs.strongloop.com/display/LB/Model+hooks