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https://github.com/codemeasandwich/mongoose-model-stream
a mongoose model generator with a change stream
https://github.com/codemeasandwich/mongoose-model-stream
changes-stream mongodb mongoose server-to-server stream websocket
Last synced: about 1 month ago
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a mongoose model generator with a change stream
- Host: GitHub
- URL: https://github.com/codemeasandwich/mongoose-model-stream
- Owner: codemeasandwich
- License: apache-2.0
- Created: 2016-10-16T18:25:32.000Z (about 8 years ago)
- Default Branch: master
- Last Pushed: 2022-04-11T09:03:15.000Z (over 2 years ago)
- Last Synced: 2024-09-26T17:23:43.993Z (about 2 months ago)
- Topics: changes-stream, mongodb, mongoose, server-to-server, stream, websocket
- Language: JavaScript
- Size: 35.2 KB
- Stars: 3
- Watchers: 2
- Forks: 0
- Open Issues: 8
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# mongoose-model-stream
a mongoose model generator with a change stream
**info:**
[](https://www.npmjs.com/package/mongoose-model-stream)
[](https://www.apache.org/licenses/LICENSE-2.0)
### If this was helpful, [★ it on github](https://github.com/codemeasandwich/mongoose-model-stream)
# Install
`yarn add mongoose-model-stream`
**or**
`npm install --save mongoose-model-stream`
# How to Use
``` js
const moduleStream = require('mongoose-model-stream');
```
### constructor
This `moduleStream` function takes two arguments.
* `modelName`: The name of the model
* `schema` : The schema definition of the model.
There is also an optional 3rd argument.
* `options` OR `enableDownStream`
* options: the options **object** that will be passed to the change stream schema. You can set `enableDownStream` as a Property on options
* enableDownStream: A **boolean** to change will create change events, without listening to the stream for updates. *(Default: `true`)*
``` js
const ChatSchema = new mongoose.schema({
text: String
});
const Chat = moduleStream('Chat', ChatSchema);
```
Attached to `Chat` will be a `.stream` baced on [RxJs]. This will **emit** change events baced on [rfc6902]
The payload looks like:
| Property | Type |Description
|--- |--- |---
| patchs | Array | Present for all changes to the item. - An array of [rfc6902] operations.
| target | String(ID) | The Unique identifier for the target Object
| _id | String(ID)| The Unique identifier for this diff
| createdAt | String(Date) | The time the chage was made
| tag | String | A customisable identifier for this change
| action | String(Enum) | This will be "**CREATE**", "**UPDATE**" or "**DELETE**" depending on the state of the document in the database
| getChange | fn() ➜ Obj | an object with only the changes applied
| getTarget | fn() ➜ promise ➜ doc | get the target document from the Database
### model
#### Create
A new function will be added to the model
* `saveBy` : This is used the tag a change with who made it.
``` js
event.when = "today";
event.saveBy(user);
```
A `saveBy` **id** will be add to the change record
**Outputted change**
``` js
{ patchs:
[ {
op: 'add',
path: '/when',
value: 'today'
} ],
_id: '5a958d12fc413a44ac760fb1',
target: '5a958d11fc413a44ac760fa9',
saveBy: '5a95872c39c0be3afaeb9a86',
createdAt: '2018-08-12T04:46:02.009Z',
action: "UPDATE"
}
```
#### Update
* **"saveBy"** is also provided in the `update` function(s)
* `update`, `updateMany`, `updateOne`, `findOneAndUpdate`, `findByIdAndUpdate`
You said the **"saveBy"** bypassing it in the *"options"* argument.
This can be an **ID of an object(String)** that will be used for all patchs
or a **function** to calculate the ID for each specific updated document
```js
const conditions = {foo:true },
updateValues = {setBarTo:false},
options = {savedBy:(oldDoc,newDoc,patchs)=>oldDoc.user_id}
event.updateMany(conditions,update,options)
```
### tag
A custom string denoting the change can be added to the following functions
* Create
e.g. `` const event = await Module.create({ text:updateTextTag },{ tag :"FOO_1" })``
* save
e.g. ``event.save("FOO_2")`` or ``event.save({ tag :"FOO_3"})``
* saveBy
e.g. ``event.saveBy(user,"FOO_4")``
* update
e.g. ``Module.updateOne({_id},{$set:{text:"bar"}},{ tag : "FOO_5" })``
----
# run samples
``` bash
node example/sample.js
```
# Example
``` js
require('mongoose-model-stream');
const { Schema, moduleStream } = require('mongoose');
// create a schema
const ChatSchema = new Schema({ text: String }, { timestamps: true });
// create a module
const Chat = moduleStream('Chat', ChatSchema);
// subscribe to change events
Chat.stream.subscribe(console.log, console.error, console.info);
Chat.create({ text: "foo" })
.then(function (chatMessage) {
chatMessage.text = "bar";
return chatMessage.save();
}).then(function (chatMessage) {
chatMessage.text = "baz";
chatMessage.save();
}).catch(console.error);
```
### Output:
**Change: 1**
``` js
{ patchs:
[ {
op: 'add',
path: '/text',
value: :'foo'
}, {
op: 'add',
path: '/_id',
value: '5a86eea992f78d54f1cd65e9'
}, {
op: 'add',
path: '/updatedAt',
value: :'2018-08-12T04:46:01.993Z'
}, {
op: 'add',
path: '/createdAt',
value: '2018-08-12T04:46:01.993Z'
} ],
_id: '5a86eeaa92f78d54f1cd65ea',
target: '5a86eea992f78d54f1cd65e9',
createdAt: '2018-08-12T04:46:02.009Z',
action: "CREATE"
}
```
**Change: 2**
``` js
{ patchs:
[ { op: 'test', path: '/updatedAt', value: '2018-08-12T04:46:01.993Z' },
{ op: 'replace', path: '/text', value: 'bar' },
{ op: 'replace', path: '/updatedAt', value: '2018-08-12T04:46:02.116Z' }, ],
_id: '5a86eeaa92f78d54f1cd65eb',
target: '5a86eea992f78d54f1cd65e9',
createdAt: '2018-08-12T04:46:02.022Z',
action: "UPDATE"
}
```
**Change: 3**
``` js
{ patchs:
[ { op: 'test', path: '/updatedAt', value: '2018-08-12T04:46:02.116Z' },
{ op: 'replace', path: '/text', value: 'baz' },
{ op: 'replace', path: '/updatedAt', value: '2018-08-12T04:46:02.342Z' }, ],
_id: '5a86eeaa92f78d54f1cd65ec',
target: '5a86eea992f78d54f1cd65e9',
createdAt: '2018-08-12T04:46:02.122Z',
action: "UPDATE"
}
```
[RxJs]: http://reactivex.io/rxjs/
[rfc6902]: https://tools.ietf.org/html/rfc6902