Data managementContribute

Lenra Data system is based on Mongo. Using our API, you can access and manage this data and utilize the View component to adapt your application interface.

API

To manage the data in your application, you can utilize our REST API. To make a basic API call within Listeners, you can use the "api" object that is passed as the third parameter. This object provides you with the server URL and your authentication token.

CRUD

Create a document, give the content in the body

- POST `${api.url}/app/colls/${coll}/docs`

Read a specific document

- GET `${api.url}/app/colls/${coll}/docs/${id}`

Update a document, give the changes in the body

- PUT `${api.url}/app/colls/${coll}/docs/${doc._id}`

Delete a document

- DELETE `${api.url}/app/colls/${coll}/docs/${doc._id}`

Advanced Mongo functions

find

The MongoDB find function can find many documents in a collection filtered by the query filter.

Run find request, give find params in body like:

• query: the query filter
• projection: the projection map more details here

- POST `${api.url}/app/colls/${coll}/docs/find` 

The projection allows you to filter the keys in the return object, by giving a projection map, all keys set to true will be returned, the default values are false, example:

We have in the users collection

{
    "_id": "123456",
    "name": "John",
    "age": 20
}

View

Lenra also allows the use of Mongo find to customize the view's results according to the requested data. Additionally, this behavior automatically updates the interface when a data point corresponding to the view query is changed.

Examples

The next example will call the filteredUsers view with the user called Thomas as input data:

{
    "type": "view",
    "name": "filteredUsers",
    "find": {
        "coll": "users",
        "query": {
            "name": "Thomas"
        }
    }
}

You can get only the names of the users by using this projection:

{
    "type": "view",
    "name": "userList",
    "find": {
        "coll": "users",
        "projection": {"name": true}
    }
}

Limitations

In order to manage realtime refresh of the view we had to implement the Mongo operators in our query-parser project. Since it takes time to implement all the operators (and that we also have lot of work on Lenra) we only have implemented a short list of them. We will implement the rest of them soon, but if you want to help you can look at the list of operator task.

Managed operators

Comparison

Logical

Element

Array