clientdatastore

Unified implementation for saving data in browsers. Gracefully degrades from IndexedDB to WebSQL to Heap.

clientdatastore is a fast and simple storage library for JavaScript. It improves the offline experience of your web app by using asynchronous storage (IndexedDB or WebSQL) with a simple API.

clientdatastore uses LocalStorage/Heap in browsers with no IndexedDB or WebSQL support.

To use clientdatastore, just drop a single JavaScript file into your page:

install with npm:

npm install clientdatastore

This module is compatible with browserify and lasso.

Usage Details

var ds = require('clientdatastore');


var selectedDataStore = ds.get();


var resolvedDataStore = ds.get(function() {
    var ua = window.navigator.userAgent.toLowerCase();
    if (ua.indexOf('msie') > -1) {
        return 'heap';
    } else if (ua.indexOf('safari') > -1 && ua.indexOf('chrome') === -1) {
        return 'heap';
    }
    return 'idb';
});


var resolvedDataStore = ds.get('heap');


var database1 = selectedDataStore.init('DB_NAME_1', meta);
database1.insert();

var database2 = selectedDataStore.init('DB_NAME_2', meta);
database2.insert();

selectedDataStore.destroy('DB_NAME_2');

More samples

Assume we need marks of all students in a class

Each student has

• roll number (unique index)

• subject1 mark

• subject2 mark

• subject3 mark

• total

Create DB, Object stores, indexes

tableMeta

{
     name: 'marksheet',
     indexes: [
         {
             name: 'rollnumber',
             unique: true
         }
     ]
}

Code Sample

var dataStore = require('clientdatastore');
dataStore.init('students', [tableMeta]);

Insert data

studentData

[
    {
        'rollnumber': 1,
        'sub1': 90,
        'sub2': 99,
        'sub3': 89,
        'total': 278
    },
    {
        'rollnumber': 2,
        'sub1': 91,
        'sub2': 100,
        'sub3': 89,
        'total': 280
    }
]

Code sample

var meta = { name: 'marksheet' }
dataStore.insert(meta, studentData);

Interfaces

init(dbName, metas)

Creates objectStores and indexes.

dbName - name of the database you want to create.

metas - Array that accepts list of ObjectStore(like table) and their indexes.

output - promise

promise resolution: empty

destory(dbName)

dbName - name of the database you want to create.

Deletes the provided database.

getStore(dbName)

metas Sample

[
    {
        name: "marksheet_jan",
        meta: [
    {name:'roll_numb', unique:true}
      ]
    },
    {
        name: "marksheet_feb",
        meta: [
            {name:'roll_numb', unique:true}
            ]
    }
]

insert(meta, data)

insert object(s) to the specified ObjectStore.

meta - Object with ObjectStore name

output - promise

promise resolution: [ids] for inserted records

Sample

meta:

{
    name: 'marksheet_jan'
}

data:

[
    {
        'rollnumber': 1,
        'sub1': 90,
        'sub2': 99,
        'sub3': 89,
        'total': 278
    }
]

select(meta, [filters])

Returns object(s) from the specified ObjectStore, based on the filter(s).

meta - Object with ObjectStore name and index name which will be used if its a non filter selectAll case

filters - {index, [filterData]}

output - promise

promise resolution: Array of objects matching the filters

Sample

meta:

{
    name: 'marksheet_jan'
}

filterData:

{
    index: rollnumber,
    data: [
        1,
        22
    ]
}

Returns records having rollnumber 1 or 22.

update(meta, filterData, data)

Updates object(s) in the specified ObjectStore, based on the filter(s) and provided data. If any property is set to undefined, those properties will be dropped when updating.

meta - Object with ObjectStore name

filter - {index, [filterData]}

data - {}

output - promise

promise resolution: empty

Sample

meta:

{
    name: 'marksheet_jan'
}

filterData:

{
    index: "rollnumber",
    data: [
        1
    ]
}

data:

{
    'rollnumber': 1,
    'sub1': 100,
    'sub2': 100,
    'sub3': 100,
    'total': 300
}

updates record will rollnumber 1 with the provided data.

remove(meta, filterData)

Delete object(s) in the specified ObjectStore, based on the filter(s). Not providing any filter will delete all entries.

meta - Object with ObjectStore name

filter - {index, [filterData]}

output - promise

promise resolution: empty

Sample

meta:

{
    name: 'marksheet_jan'
}

filterData:

{
    index: rollnumber,
    data: [
        1
    ]
}

Removes the record with rollnumber 1.