Monday, July 23, 2018

A cursor based custom pagination library for Mongoose with customizable labels.

Installation

npm install mongoose-paginate-v2

Usage

Add plugin to a schema and then use model paginate method:
var mongoose         = require('mongoose');
var mongoosePaginate = require('mongoose-paginate-v2');

var mySchema = new mongoose.Schema({ 
    /* your schema definition */ 
});

mySchema.plugin(mongoosePaginate);

var myModel = mongoose.model('SampleModel',  mySchema); 

myModel.paginate().then({}) // Usage

Model.paginate([query], [options], [callback])

Returns promise
Parameters
  • [query] {Object} - Query criteria. Documentation
  • [options] {Object}
    • [select] {Object | String} - Fields to return (by default returns all fields). Documentation
    • [sort] {Object | String} - Sort order. Documentation
    • [populate] {Array | Object | String} - Paths which should be populated with other documents. Documentation
    • [lean=false] {Boolean} - Should return plain javascript objects instead of Mongoose documents? Documentation
    • [leanWithId=true] {Boolean} - If lean and leanWithId are true, adds id field with string representation of _idto every document
    • [offset=0] {Number} - Use offset or page to set skip position
    • [page=1] {Number}
    • [limit=10] {Number}
    • [customLabels] {Object} - Developers can provide custom labels for manipulating the response data.
  • [callback(err, result)] - If specified the callback is called once pagination results are retrieved or when an error has occurred
Return value
Promise fulfilled with object having properties:
  • docs {Array} - Array of documents
  • totalDocs {Number} - Total number of documents in collection that match a query
  • limit {Number} - Limit that was used
  • hasPrevPage {Bool} - Availability of prev page.
  • hasNextPage {Bool} - Availability of next page.
  • page {Number} - Current page number
  • totalPages {Number} - Total number of pages.
  • offset {Number} - Only if specified or default page/offset values were used
  • prevPage {Number} - Previous page number if available or NULL
  • nextPage {Number} - Next page number if available or NULL
Please note that the above properties can be renamed by setting customLabel attribute.

Sample Usage

Return first 10 documents from 100

const options = {
    page: 1,
    limit: 10
};

Model.paginate({}, options, function(err, result) {
    // result.docs
    // result.totalDocs = 100
    // result.limit = 10
    // result.page = 1
    // result.totalPages = 10    
    // result.hasNextPage = true
    // result.nextPage = 2
    // result.hasPrevPage = false
    // result.prevPage = null
    
});

With custom return labels

Now developers can specify the return field names if they want. Below are the list of attributes whose name can be changed.
  • totalDocs
  • docs
  • limit
  • page
  • nextPage
  • prevPage
  • totalPages
You should pass the names of the properties you wish to changes using customLabels object in options.
Same query with custom labels
const myCustomLabels = {
    totalDocs: 'itemCount',
    docs: 'itemsList',
    limit: 'perPage',
    page: 'currentPage',
    nextPage: 'next',
    prevPage: 'prev',
    totalPages: 'pageCount'
};

const options = {
    page: 1,
    limit: 10,
    customLabels: myCustomLabels
};

Model.paginate({}, options, function(err, result) {
    // result.itemsList [here docs become itemsList]
    // result.itemCount = 100 [here totalDocs becomes itemCount]
    // result.perPage = 10 [here limit becomes perPage]
    // result.currentPage = 1 [here page becomes currentPage]
    // result.pageCount = 10 [here totalPages becomes pageCount]
    // result.next = 2 [here nextPage becomes next]
    // result.prev = null [here prevPage becomes prev]
    
    // result.hasNextPage = true [not changeable]
    // result.hasPrevPage = false [not changeable]
});

Other Examples

Using offset and limit:
Model.paginate({}, { offset: 30, limit: 10 }, function(err, result) {
    // result.docs
    // result.totalPages
    // result.limit - 10
    // result.offset - 30
});
With promise:
Model.paginate({}, { offset: 30, limit: 10 }).then(function(result) {
    // ...
});

More advanced example

var query   = {};
var options = {
    select:   'title date author',
    sort:     { date: -1 },
    populate: 'author',
    lean:     true,
    offset:   20, 
    limit:    10
};

Book.paginate(query, options).then(function(result) {
    // ...
});

Zero limit

You can use limit=0 to get only metadata:
Model.paginate({}, { offset: 100, limit: 0 }).then(function(result) {
    // result.docs - empty array
    // result.totalDocs
    // result.limit - 0
    // result.offset - 100
});

Set custom default options for all queries

config.js:
var mongoosePaginate = require('mongoose-paginate-v2');

mongoosePaginate.paginate.options = { 
    lean:  true,
    limit: 20
};
controller.js:
Model.paginate().then(function(result) {
    // result.docs - array of plain javascript objects
    // result.limit - 20
});

Tuesday, July 17, 2018

How to add title and image header to all pages while printing using DataTable

Step 1

Download below JS file and replace your print.button.js with below it,https://github.com/aravindnc/Buttons/blob/repeating-print-head/js/buttons.print.js

Step 2

Add new option repeatingHead inside the button settings.
Below are the options for repeatingHead,
{
    logo: 'Your logo URL to be repeated',
    logoPosition: 'right', // left, center, right
    logoStyle: '', // any css eg: padding:10px;
    title: '

Sample Heading

'
// your heading }
A sample is given below.
<script>
    $(document).ready(function() {
        // DataTable initialisation
        $('#example').DataTable({
            "dom": 'Bfrtip',
            "paging": true,
            "autoWidth": true,
            "columnDefs": [{
                "visible": true,
                "targets": -1
            }],
            buttons: [{
                extend: 'print',
                autoPrint: true,
                title: '',

                //For repeating heading.
                repeatingHead: {
                    logo: 'https://www.google.co.in/logos/doodles/2018/world-cup-2018-day-22-5384495837478912-s.png',
                    logoPosition: 'right',
                    logoStyle: '',
                    title: '

Sample Heading

'
} }] }); }); </script>

Step 3

If you want to remove the borders around logo, add a new class dt-print-table to your table and add below style to your css file.
@media print
{
html, body { height: auto; }
.dt-print-table, .dt-print-table thead, .dt-print-table th, .dt-print-table tr {border: 0 none !important;}
}
Thats all :)

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