SemanticScuttle/includes/js/dojo/data/util/sorter.js

81 lines
2.8 KiB
JavaScript

if(!dojo._hasResource["dojo.data.util.sorter"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
dojo._hasResource["dojo.data.util.sorter"] = true;
dojo.provide("dojo.data.util.sorter");
dojo.data.util.sorter.basicComparator = function( /*anything*/ a,
/*anything*/ b){
// summary:
// Basic comparision function that compares if an item is greater or less than another item
// description:
// returns 1 if a > b, -1 if a < b, 0 if equal.
// undefined values are treated as larger values so that they're pushed to the end of the list.
var ret = 0;
if(a > b || typeof a === "undefined" || a === null){
ret = 1;
}else if(a < b || typeof b === "undefined" || b === null){
ret = -1;
}
return ret; //int, {-1,0,1}
};
dojo.data.util.sorter.createSortFunction = function( /* attributes array */sortSpec,
/*dojo.data.core.Read*/ store){
// summary:
// Helper function to generate the sorting function based off the list of sort attributes.
// description:
// The sort function creation will look for a property on the store called 'comparatorMap'. If it exists
// it will look in the mapping for comparisons function for the attributes. If one is found, it will
// use it instead of the basic comparator, which is typically used for strings, ints, booleans, and dates.
// Returns the sorting function for this particular list of attributes and sorting directions.
//
// sortSpec: array
// A JS object that array that defines out what attribute names to sort on and whether it should be descenting or asending.
// The objects should be formatted as follows:
// {
// attribute: "attributeName-string" || attribute,
// descending: true|false; // Default is false.
// }
// store: object
// The datastore object to look up item values from.
//
var sortFunctions=[];
function createSortFunction(attr, dir){
return function(itemA, itemB){
var a = store.getValue(itemA, attr);
var b = store.getValue(itemB, attr);
//See if we have a override for an attribute comparison.
var comparator = null;
if(store.comparatorMap){
if(typeof attr !== "string"){
attr = store.getIdentity(attr);
}
comparator = store.comparatorMap[attr]||dojo.data.util.sorter.basicComparator;
}
comparator = comparator||dojo.data.util.sorter.basicComparator;
return dir * comparator(a,b); //int
};
}
for(var i = 0; i < sortSpec.length; i++){
sortAttribute = sortSpec[i];
if(sortAttribute.attribute){
var direction = (sortAttribute.descending) ? -1 : 1;
sortFunctions.push(createSortFunction(sortAttribute.attribute, direction));
}
}
return function(rowA, rowB){
var i=0;
while(i < sortFunctions.length){
var ret = sortFunctions[i++](rowA, rowB);
if(ret !== 0){
return ret;//int
}
}
return 0; //int
}; // Function
};
}