/**
* Initialize DataStore from one of supported source formats:
*
* - Flatten(fastest): <pre>{fieldCount: K, rowCount: Z, values: [field1Name, ..., fieldKName, row1field1Value, ..., row1fieldKValue, row2field1Value,..]}</pre>
* - Array-of-array : <pre>[[row1field1Value, ..., row1fieldKValue], ..., [rowZfield1Value, ... rowZfieldKValue]</pre>
* - Array-of-object : <pre>[{field1Name: row1field1Value, ..., fieldKName: row1fieldKValue}, ....]</pre>
*
* Can (optionally) convert source field names to new names using keyMap array.
* @example
*
var ds = new TubDataStore('my_entity');
// init empty (rowCount=0) dataStore with provided fields.
// In case keyMap is omitted we consider it contain one attribute 'ID'
ds.initialize([]); // the same as ds.initialize([], ['ID']);
ds.initialize([], ['ID', 'name', {from: 'AGE', to: 'age'}]);
// Initialize dataStore from array-of-object representation
// Resulting datstore will contain 3 field: ID, nam, age (in order, they listen in keyMap array).
// During initialization we convert fiend name 'AGE' -> age;
ds.initialize([{ID: 10, name: 'Jon', AGE: 10}, {ID: 20, name: 'Smith', AGE: 63}],
['ID', 'name', {from: 'AGE', to: 'age'}]);
//the same, but do not convert AGE->age. Result dataset field order is unknown
ds.initialize([{ID: 10, name: 'Jon', AGE: 10}, {ID: 20, name: 'Smith', AGE: 63}]);
//result dataset will contain only two field 'ID' & 'age'
ds.initialize([{ID: 10, name: 'Jon', AGE: 10}, {ID: 20, name: 'Smith', AGE: 63}],
['ID', {from: 'AGE', to: 'age'}]);
// Initialize dataStore from Array-of-array data
// in this case keyMap is mandatory.
// In case of mapping from is zero-based index of source element in row array
ds.initialize([[10, 'Jon', 10], [20, 'Smith', 63]], ['ID', 'name', 'age']);
// or use mapping
ds.initialize([[10, 'Jon', 10], [20, 'Smith', 63]],
['ID', {from: 2, to: 'age'}, {from: 1, to: 'name'}]);
* @memberof TubDataStore
* @param {Object|Array} source
* @param {Array.<String|Object>} [keyMap] Optional mapping of source field names to new field names
* @returns {TubDataStore}
*/
TubDataStore.initialize = function (source, keyMap) {
var
flatArray = [], resultFields = [], sourceFields = [],
i, j, l, rowCount, fieldCount, row;
function keyMap2Mapping(keyMap, isIndexBased) {
var i, l, elm;
for (i = 0, l = keyMap.length; i < l; i++) {
elm = keyMap[i];
if (typeof elm === 'object') {
sourceFields.push(isIndexBased ? parseInt(elm.from, 10) : elm.from);
resultFields.push(elm.to);
} else {
sourceFields.push(isIndexBased ? i : elm);
resultFields.push(elm);
}
}
}
if (Array.isArray(source)) {
rowCount = source.length;
if (rowCount === 0) { // 1) empty store
keyMap2Mapping((keyMap && keyMap.length) ? keyMap : ['ID']);
this.initFromJSON({fieldCount: resultFields.length, rowCount: 0, values: resultFields}); // empty dataStore initialization
} else if (Array.isArray(source[0])) { // 2) Array-of-array
if ((!keyMap) || (!keyMap.length)) {
throw new Error('TubDataStore.initialize: for array-of-array keyMap is required');
}
keyMap2Mapping(keyMap, true);
fieldCount = resultFields.length;
for (i = 0; i < fieldCount; i++) { // field names
flatArray.push(resultFields[i]);
}
for (i = 0; i < rowCount; i++) { // data
row = source[i];
for (j = 0; j < fieldCount; j++) {
flatArray.push(row[sourceFields[j]]); // add source field using it index in keyMap
}
}
this.initFromJSON({fieldCount: fieldCount, rowCount: rowCount, values: flatArray});
} else if (typeof source[0] === 'object') { // 3) Array-of-object
keyMap2Mapping((keyMap && keyMap.length) ? keyMap : Object.keys(source[0]));
fieldCount = resultFields.length;
for (i = 0; i < fieldCount; i++) { // field names
flatArray.push(resultFields[i]);
}
for (i = 0; i < rowCount; i++) { // data
row = source[i];
for (j = 0; j < fieldCount; j++) {
flatArray.push(row[sourceFields[j]]); // add source field using it name from keyMap
}
}
this.initFromJSON({fieldCount: fieldCount, rowCount: rowCount, values: flatArray});
} else {
throw new Error('TubDataStore.initialize: invalid source format for TubDataStore.initialize');
}
} else if ((typeof source === 'object') && (source.fieldCount > 0) && (source.rowCount > 0)) { //flatten
if (keyMap) {
if (keyMap.length !== source.fieldCount) {
throw new Error('TubDataStore.initialize: for flatten data keyMap length must be equal to fieldCount');
}
for (i = 0, l = source.fieldCount; i < l; i++) {
if (typeof keyMap[i] !== 'string') {
throw new Error('TubDataStore.initialize: for flatten data keyMap must contain only field names');
}
source.values[i] = keyMap[i];
}
}
this.initFromJSON({fieldCount: source.fieldCount, rowCount: source.rowCount, values: source.values}); // order of properties is important for native reader realization
} else {
throw new Error('TubDataStore.initialize: invalid source format');
}
return this;
};