jquery/jquery

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src/data.js

Summary

Maintainability
A
3 hrs
Test Coverage
define( [
    "./core",
    "./core/access",
    "./core/camelCase",
    "./data/var/dataPriv",
    "./data/var/dataUser"
], function( jQuery, access, camelCase, dataPriv, dataUser ) {

"use strict";

//    Implementation Summary
//
//    1. Enforce API surface and semantic compatibility with 1.9.x branch
//    2. Improve the module's maintainability by reducing the storage
//        paths to a single mechanism.
//    3. Use the same single mechanism to support "private" and "user" data.
//    4. _Never_ expose "private" data to user code (TODO: Drop _data, _removeData)
//    5. Avoid exposing implementation details on user objects (eg. expando properties)
//    6. Provide a clear path for implementation upgrade to WeakMap in 2014

var rbrace = /^(?:\{[\w\W]*\}|\[[\w\W]*\])$/,
    rmultiDash = /[A-Z]/g;

function getData( data ) {
    if ( data === "true" ) {
        return true;
    }

    if ( data === "false" ) {
        return false;
    }

    if ( data === "null" ) {
        return null;
    }

    // Only convert to a number if it doesn't change the string
    if ( data === +data + "" ) {
        return +data;
    }

    if ( rbrace.test( data ) ) {
        return JSON.parse( data );
    }

    return data;
}

function dataAttr( elem, key, data ) {
    var name;

    // If nothing was found internally, try to fetch any
    // data from the HTML5 data-* attribute
    if ( data === undefined && elem.nodeType === 1 ) {
        name = "data-" + key.replace( rmultiDash, "-$&" ).toLowerCase();
        data = elem.getAttribute( name );

        if ( typeof data === "string" ) {
            try {
                data = getData( data );
            } catch ( e ) {}

            // Make sure we set the data so it isn't changed later
            dataUser.set( elem, key, data );
        } else {
            data = undefined;
        }
    }
    return data;
}

jQuery.extend( {
    hasData: function( elem ) {
        return dataUser.hasData( elem ) || dataPriv.hasData( elem );
    },

    data: function( elem, name, data ) {
        return dataUser.access( elem, name, data );
    },

    removeData: function( elem, name ) {
        dataUser.remove( elem, name );
    },

    // TODO: Now that all calls to _data and _removeData have been replaced
    // with direct calls to dataPriv methods, these can be deprecated.
    _data: function( elem, name, data ) {
        return dataPriv.access( elem, name, data );
    },

    _removeData: function( elem, name ) {
        dataPriv.remove( elem, name );
    }
} );

jQuery.fn.extend( {
    data: function( key, value ) {
        var i, name, data,
            elem = this[ 0 ],
            attrs = elem && elem.attributes;

        // Gets all values
        if ( key === undefined ) {
            if ( this.length ) {
                data = dataUser.get( elem );

                if ( elem.nodeType === 1 && !dataPriv.get( elem, "hasDataAttrs" ) ) {
                    i = attrs.length;
                    while ( i-- ) {

                        // Support: IE 11 only
                        // The attrs elements can be null (#14894)
                        if ( attrs[ i ] ) {
                            name = attrs[ i ].name;
                            if ( name.indexOf( "data-" ) === 0 ) {
                                name = camelCase( name.slice( 5 ) );
                                dataAttr( elem, name, data[ name ] );
                            }
                        }
                    }
                    dataPriv.set( elem, "hasDataAttrs", true );
                }
            }

            return data;
        }

        // Sets multiple values
        if ( typeof key === "object" ) {
            return this.each( function() {
                dataUser.set( this, key );
            } );
        }

        return access( this, function( value ) {
            var data;

            // The calling jQuery object (element matches) is not empty
            // (and therefore has an element appears at this[ 0 ]) and the
            // `value` parameter was not undefined. An empty jQuery object
            // will result in `undefined` for elem = this[ 0 ] which will
            // throw an exception if an attempt to read a data cache is made.
            if ( elem && value === undefined ) {

                // Attempt to get data from the cache
                // The key will always be camelCased in Data
                data = dataUser.get( elem, key );
                if ( data !== undefined ) {
                    return data;
                }

                // Attempt to "discover" the data in
                // HTML5 custom data-* attrs
                data = dataAttr( elem, key );
                if ( data !== undefined ) {
                    return data;
                }

                // We tried really hard, but the data doesn't exist.
                return;
            }

            // Set the data...
            this.each( function() {

                // We always store the camelCased key
                dataUser.set( this, key, value );
            } );
        }, null, value, arguments.length > 1, null, true );
    },

    removeData: function( key ) {
        return this.each( function() {
            dataUser.remove( this, key );
        } );
    }
} );

return jQuery;
} );