Easy way to get multi-level javascript object property - javascript

I always need to deal with multi-level js objects where existence of properties are not certain:
try { value1 = obj.a.b.c; } catch(e) { value1 = 1; }
try { value2 = obj.d.e.f; } catch(e) { value2 = 2; }
......
Is there an easier way or a generic function (e.g. ifnull(obj.d.e.f, 2) ) that does not require a lot of try catches?

var value1 = (obj.a && obj.a.b && obj.a.b.c) || 1;
http://jsfiddle.net/DerekL/UfJEQ/
Or use this:
function ifNull(obj, key, defVal){
var keys = key.split("."), value;
for(var i = 0; i < keys.length; i++){
if(typeof obj[keys[i]] !== "undefined"){
value = obj = obj[keys[i]];
}else{
return defVal;
}
}
return value;
}
var value1 = ifNull(obj, "a.b.c", 1);

You could always create a helper function.
function isUndefined(root, path, defaultVal) {
var parts = path.split('.'),
i = 0,
len = parts.length,
o = root || {}, v;
while ((typeof (v = o[parts[i]]) === 'object', o = v) && ++i < len);
return (typeof v === 'undefined' || i !== len)? defaultVal: v;
}
var obj = {a: { b: { test: 'test' }}}, v;
v = isUndefined(obj, 'a.b.test', 1); //test
v = isUndefined(obj, 'a.test', 1); //1

Using lodash you can do this easily**(node exists and empty check for that node)**..
var lodash = require('lodash-contrib');
function invalidateRequest(obj, param) {
var valid = true;
param.forEach(function(val) {
if(!lodash.hasPath(obj, val)) {
valid = false;
} else {
if(lodash.getPath(obj, val) == null || lodash.getPath(obj, val) == undefined || lodash.getPath(obj, val) == '') {
valid = false;
}
}
});
return valid;
}
Usage:
leaveDetails = {
"startDay": 1414998000000,
"endDay": 1415084400000,
"test": { "test1" : 1234 }
};
var validate;
validate = invalidateRequest(leaveDetails, ['startDay', 'endDay', 'test.test1']);
it will return boolean.

Related

Need to work this string in as a parameter in my url

I have a filter script that ads a value to my url trough a set of checkboxes. Each checkbox group can only ad one value.
First click on a checkboxgroup looks like this:
/Network-CAT-cables?fss=yellow
Where the fss=yellow is the added parameter. A click on another chekcbox group would look like this:
/Network-CAT-cables?fss=yellow+cat6
If I check another checkbox in one of the above groups it replaces the previous value.
Now i need to add a parameter that looks like this:
&sps=d211av450240_2.0
If I set that as a value in the checkbox it kinda work. It ads the parameter and sort after it. And if i add a "normal" value it places before it. and that works too - like this:
?fss=yellow+cat5&sps=d211av450240_2.0
The problem is that when I have several of the new custom parameter in a group. In the other checkbox groups I can only have one value - and the chosen one replaces the old parameter. with the custom parameter I want to add it just ads on, instead of replaceing - like this.
?fss=yellow+cat5&sps=d211av450240_2.0+&sps=d211av450240_1.0
The correct outcome would have been
?fss=yellow+cat5&sps=d211av450240_1.0
I know this is because of the "&" in the parameter - but unsure how to work it out. I cant change the parameter either - and I know checkboxes are ment to be for multiple choices, but its like this for a reason.
My filterscript:
$(document).ready(function(){
new function(settings) {
var $separator = settings.separator || '&';
var $spaces = settings.spaces === false ? false : true;
var $suffix = settings.suffix === false ? '' : '[]';
var $prefix = settings.prefix === false ? false : true;
var $hash = $prefix ? settings.hash === true ? "#" : "?" : "";
var $numbers = settings.numbers === false ? false : true;
jQuery.query = new function() {
var is = function(o, t) {
return o != undefined && o !== null && (!!t ? o.constructor == t : true);
};
var parse = function(path) {
var m, rx = /\[([^[]*)\]/g, match = /^([^[]+)(\[.*\])?$/.exec(path), base = match[1], tokens = [];
while (m = rx.exec(match[2])) tokens.push(m[1]);
return [base, tokens];
};
var set = function(target, tokens, value) {
var o, token = tokens.shift();
if (typeof target != 'object') target = null;
if (token === "") {
if (!target) target = [];
if (is(target, Array)) {
target.push(tokens.length == 0 ? value : set(null, tokens.slice(0), value));
} else if (is(target, Object)) {
var i = 0;
while (target[i++] != null);
target[--i] = tokens.length == 0 ? value : set(target[i], tokens.slice(0), value);
} else {
target = [];
target.push(tokens.length == 0 ? value : set(null, tokens.slice(0), value));
}
} else if (token && token.match(/^\s*[0-9]+\s*$/)) {
var index = parseInt(token, 10);
if (!target) target = [];
target[index] = tokens.length == 0 ? value : set(target[index], tokens.slice(0), value);
} else if (token) {
var index = token.replace(/^\s*|\s*$/g, "");
if (!target) target = {};
if (is(target, Array)) {
var temp = {};
for (var i = 0; i < target.length; ++i) {
temp[i] = target[i];
}
target = temp;
}
target[index] = tokens.length == 0 ? value : set(target[index], tokens.slice(0), value);
} else {
return value;
}
return target;
};
var queryObject = function(a) {
var self = this;
self.keys = {};
if (a.queryObject) {
jQuery.each(a.get(), function(key, val) {
self.SET(key, val);
});
} else {
self.parseNew.apply(self, arguments);
}
return self;
};
queryObject.prototype = {
queryObject: true,
parseNew: function(){
var self = this;
self.keys = {};
jQuery.each(arguments, function() {
var q = "" + this;
q = q.replace(/^[?#]/,''); // remove any leading ? || #
q = q.replace(/[;&]$/,''); // remove any trailing & || ;
if ($spaces) q = q.replace(/[+]/g,' '); // replace +'s with spaces
jQuery.each(q.split(/[&;]/), function(){
var key = decodeURIComponent(this.split('=')[0] || "");
var val = decodeURIComponent(this.split('=')[1] || "");
if (!key) return;
if ($numbers) {
if (/^[+-]?[0-9]+\.[0-9]*$/.test(val)) // simple float regex
val = parseFloat(val);
else if (/^[+-]?[0-9]+$/.test(val)) // simple int regex
val = parseInt(val, 10);
}
val = (!val && val !== 0) ? true : val;
self.SET(key, val);
});
});
return self;
},
has: function(key, type) {
var value = this.get(key);
return is(value, type);
},
GET: function(key) {
if (!is(key)) return this.keys;
var parsed = parse(key), base = parsed[0], tokens = parsed[1];
var target = this.keys[base];
while (target != null && tokens.length != 0) {
target = target[tokens.shift()];
}
return typeof target == 'number' ? target : target || "";
},
get: function(key) {
var target = this.GET(key);
if (is(target, Object))
return jQuery.extend(true, {}, target);
else if (is(target, Array))
return target.slice(0);
return target;
},
SET: function(key, val) {
var value = !is(val) ? null : val;
var parsed = parse(key), base = parsed[0], tokens = parsed[1];
var target = this.keys[base];
this.keys[base] = set(target, tokens.slice(0), value);
return this;
},
set: function(key, val) {
return this.copy().SET(key, val);
},
REMOVE: function(key) {
return this.SET(key, null).COMPACT();
},
remove: function(key) {
return this.copy().REMOVE(key);
},
EMPTY: function() {
var self = this;
jQuery.each(self.keys, function(key, value) {
delete self.keys[key];
});
return self;
},
load: function(url) {
var hash = url.replace(/^.*?[#](.+?)(?:\?.+)?$/, "$1");
var search = url.replace(/^.*?[?](.+?)(?:#.+)?$/, "$1");
return new queryObject(url.length == search.length ? '' : search, url.length == hash.length ? '' : hash);
},
empty: function() {
return this.copy().EMPTY();
},
copy: function() {
return new queryObject(this);
},
COMPACT: function() {
function build(orig) {
var obj = typeof orig == "object" ? is(orig, Array) ? [] : {} : orig;
if (typeof orig == 'object') {
function add(o, key, value) {
if (is(o, Array))
o.push(value);
else
o[key] = value;
}
jQuery.each(orig, function(key, value) {
if (!is(value)) return true;
add(obj, key, build(value));
});
}
return obj;
}
this.keys = build(this.keys);
return this;
},
compact: function() {
return this.copy().COMPACT();
},
toString: function() {
var i = 0, queryString = [], chunks = [], self = this;
var encode = function(str) {
str = str + "";
if ($spaces) str = str.replace(/ /g, "+");
return encodeURIComponent(str);
};
var addFields = function(arr, key, value) {
if (!is(value) || value === false) return;
var o = [encode(key)];
if (value !== true) {
o.push("=");
o.push(encode(value));
}
arr.push(o.join(""));
};
var build = function(obj, base) {
var newKey = function(key) {
return !base || base == "" ? [key].join("") : [base, "[", key, "]"].join("");
};
jQuery.each(obj, function(key, value) {
if (typeof value == 'object')
build(value, newKey(key));
else
addFields(chunks, newKey(key), value);
});
};
build(this.keys);
if (chunks.length > 0) queryString.push($hash);
queryString.push(chunks.join($separator));
return queryString.join("");
}
};
return new queryObject(location.search, location.hash);
};
}(jQuery.query || {}); // Pass in jQuery.query as settings object
function removeFSS() {
ga("send", "event", "button", "click", "filter-clear", "input");
var t = encodeURI(unescape($.query.set("fss", '')));
var n = window.location.href.split("?")[0]; window.location.href = n + t
}
function getFSS() {
var D = jQuery('.filterGenius input, .filterGenius select').serializeArray();
var O = {};
jQuery.each(D, function(_, kv) {
if (O.hasOwnProperty(kv.name)) {
O[kv.name] = jQuery.makeArray(O[kv.name]);
O[kv.name].push(clean(kv.value, ""));
}
else {
O[kv.name] =kv.value;
}
});
var V = [];
for(var i in O)
if(jQuery.isArray(O[i]))
V.push(O[i].join("+"));
else
V.push(O[i]);
V = jQuery.grep(V,function(n){ return(n) });
return V.join("+");
}
$(document).ready(function () {
$(".filterGenius input").each(function () {
if (window.location.href.indexOf($(this).val()) >= 0) {
$(this).attr("checked", "checked")
}
});
$(".filterGenius select option").each(function () {
if (window.location.href.indexOf($(this).val()) >= 0) {
$(this).attr('selected', true);
}
});
$(".filterGenius input, .filterGenius select").change(function () {
var s = encodeURI(unescape(jQuery.query.set("fss", getFSS())));
var o = window.location.href.split("?")[0];
$(".filterGenius input, .filterGenius select").attr("disabled", true);
window.location.href = o + s
});
});
$('input[type="checkbox"]').on('change', function() {
$('input[name="' + this.name + '"]').not(this).prop('checked', false);
});
});

traversing a json for empty array value

i have a below json
{
"loanDetails": [
{
"vehicleDetail": {
"RCBookImageReferences": {
"imagePathReferences": [
{
}
]
}
},
"chargeDetails": [
{
}
],
"commissionDetails": [
{
}
],
"disbursementDetails": [
{
}
]
}
]
}
in the above json i need to traverse every key and if i find it emty then set the parent as empty array ie the output should be as below
{"loanDetails":[]}
i used the code below
function isEmpty(obj) {
for(var prop in obj) {
if(obj.hasOwnProperty(prop))
return false;
}
return true;
}
But it did not give me the expected result.I'm stuck here any help will be much helpful.
The function clean takes an object and loops over its keys, calling clean recursively
on each object-valued property.
If the result of cleaning is an empty object, delete the key in question.
If the object itself turns out to be empty, return undefined, triggering deletion of the property holding that object at the higher level.
function clean(obj) {
var isEmpty = true;
for (var key in obj) {
var val = obj[key];
if (val === null || typeof val !== 'object' || (obj[key] = clean(val))) {
isEmpty = false;
} else {
delete obj[key];
}
}
return isEmpty ? undefined : obj;
}
>> a = { x: 1, b: { y: [] }, c: { d: { } } }
>> clean(a)
<< Object {x: 1}
This should make it recursive. With two solutions.
Solution 1: empty test function
var boolValue = true;
for(var prop in obj) {
if(obj.hasOwnProperty(prop) && typeof obj[prop] === 'object')
{
boolValue = recursiveIsEmpty(obj[prop]);
}
else
{
return false;
}
}
return boolValue ;
//test and set empty string
recursiveIsEmpty(jsonDataObj['loanDetails']) ? jsonDataObj['loanDetails'] = [] : null;
Solution 2 recursive empty function that empties parent obj
function recursiveIsEmpty(obj) {
var boolValue = true;
for(var prop in obj) {
if(obj.hasOwnProperty(prop) && typeof obj[prop] === 'object')
{
boolValue = recursiveIsEmpty(obj[prop]);
if (boolValue)
{
delete obj[prop]; //an object is empty. Delete from parent;
}
}
else
{
return false;
}
}
return boolValue; //returns an empty object
}
recursiveIsEmpty(jsonDataObj['loanDetails']) //returns jsonDataObj['loanDetails'] = [];
This checks if obj has a property that is an object. If so load that object and check it's properties. If not return false, because that will be string or number and that confirms the object is not empty.
Your JSON-string is not valid. When corrected, you can use a reviver function parameter (see MDN) to remove 'empty' arrays (aka properties with criteria you specify).
To be clear, the reviver function takes care of the traversing on all levels of the parsed object. If it returns undefined the property is removed from the object. The reviver used in the snippet thus removes all properties containing arrays with empty objects, or empty arrays.
The snippet demonstrates this.
// json string corrected
var foo = '{"loanDetails": [{"vehicleDetail": {"RCBookImageReferences": '+
'{"imagePathReferences": [{}]}}, "chargeDetails": [{}],'+
'"commissionDetails": [{}],"disbursementDetails": [{}]}]}';
// parse it, using reviver parameter
var fooparsed = JSON.parse( foo,
function (key, value) { //<= reviver here
return (value.length && value.length == 1 &&
value[0] instanceof Object &&
Object.keys(value[0]).length == 0) ||
value instanceof Array && !value.length
? undefined : value;
}
);
// print
Helpers.log2Screen( Object.print(fooparsed) );
<script src="http://kooiinc.github.io/JSHelpers/Helpers-min.js"></script>
if you are doing this using ajax then you should go with seriallizing the jason array using javascript.
at the time of passing data through json
data: "your data",
use this
data:$(form).serialize(),
it will pass all the key of that form which you are passing ,
if you want to see its result the try to print it on console
var inputObj = {
"loanDetails": [{
"vehicleDetail": {
"RCBookImageReferences": {
"imagePathReferences": [{}]
}
},
"chargeDetails": [{}],
"commissionDetails": [{}],
"disbursementDetails": [{}]
}, {
"vehicleDetail": {
"RCBookImageReferences": {
"imagePathReferences": [{
"Valid": "Working"
}]
}
},
"chargeDetails": [{}],
"commissionDetails": [{}],
"disbursementDetails": [{}]
}],
"Superman": {
"Name": ""
},
"SpiderMan": {
"Name": "Senthil"
}
}
function flatten(target, opts) {
var output = {},
opts = opts || {},
delimiter = opts.delimiter || '.'
function getkey(key, prev) {
return prev ? prev + delimiter + key : key
};
function step(object, prev) {
Object.keys(object).forEach(function(key) {
var isarray = opts.safe && Array.isArray(object[key]),
type = Object.prototype.toString.call(object[key]),
isobject = (type === "[object Object]" || type === "[object Array]")
if (!isarray && isobject) {
return step(object[key], getkey(key, prev))
}
output[getkey(key, prev)] = object[key]
});
if (Object.keys(object) == "") {
if (object instanceof Array) {
output[prev] = [];
} else {
output[prev] = {};
}
}
};
step(target)
return output
};
function unflatten(target, opts) {
var opts = opts || {},
delimiter = opts.delimiter || '.',
result = {}
if (Object.prototype.toString.call(target) !== '[object Object]') {
return target
}
function getkey(key) {
var parsedKey = parseInt(key)
return (isNaN(parsedKey) ? key : parsedKey)
};
Object.keys(target).forEach(function(key) {
var split = key.split(delimiter),
firstNibble, secondNibble, recipient = result
firstNibble = getkey(split.shift())
secondNibble = getkey(split[0])
while (secondNibble !== undefined) {
if (recipient[firstNibble] === undefined) {
recipient[firstNibble] = ((typeof secondNibble === 'number') ? [] : {})
}
recipient = recipient[firstNibble]
if (split.length > 0) {
firstNibble = getkey(split.shift())
secondNibble = getkey(split[0])
}
}
// unflatten again for 'messy objects'
recipient[firstNibble] = unflatten(target[key])
});
//Array Check
var keys = Object.keys(result);
if (keys.length > 0 && keys[0] === "0") {
var output = [];
keys.forEach(function(key) {
output.push(result[key])
});
return output;
}
return result
};
var flatted = flatten(inputObj);
var keys = Object.keys(flatted);
keys.forEach(function(key) {
if (JSON.stringify(flatted[key]) === "{}" || JSON.stringify(flatted[key]) == "") {
// console.log(key)
delete flatted[key];
var paths = key.split(".");
if (paths.length >= 2) {
var int = parseInt(paths[1])
if (isNaN(int)) {
key = paths[0];
flatted[key] = {};
} else {
key = paths[0] + "." + int;
flatted[key] = {};
}
var newKeys = Object.keys(flatted);
for (var j = 0; j < newKeys.length; j++) {
var omg = newKeys[j];
if (omg.indexOf(key) != -1 && omg.length > key.length) {
delete flatted[key];
}
}
}
}
})
console.log(flatted)
var output = unflatten(flatted);
alert(JSON.stringify(output))

Search object with namespace / key

I'm trying to write a function that can look up a namespace and value in a JavaScript object and return the key.
Image this data:
var o = {
map: {
lat : -33.86749,
lng : 151.20699,
zoom : 12
},
filters : {
animals : {
dogs: {
myDog : 'fido'
}
}
}
};
function get(namespace, key){
//TODO
}
get('filters.animals.dogs', 'myDog')
How would you build a function that does this dynamically - no matter the depth of the namespace?
This function is somewhat close, only it modifies the original object which we don't want ofcourse:
var get = function(obj, namespace, key, value) {
var parts = namespace.split('.');
for(var i = 0; i < parts.length; i++) {
if(typeof obj[parts[i]] == 'undefined'){
obj[parts[i]] = {};
}
obj = obj[parts[i]];
}
return obj[key] = value;
};
Reason for the madness is that I cannot expose the object. It must remain private and a public method must spit out a result.
Give this a try.
function get(namespace, key) {
var parts = namespace.split('.'),
i = 0,
l = parts.length,
obj = o;
while ( i < l ) {
obj = obj[parts[i]];
if ( ! obj ) break;
i++;
}
return obj && obj[key] ? obj[key] : null;
}
I have created a fiddle with working code. Hope that helps.
http://jsfiddle.net/RdhJF/2/
var o = {
map: {
lat : -33.86749,
lng : 151.20699,
zoom : 12
},
filters : {
animals : {
dogs: {
myDog : 'fido'
}
}
}
};
function get(obj, namespace)
{
var parts = namespace.split('.');
if(parts.length==0)
return -1;
var previousValue = obj;
for(var i = 0; i < parts.length; i++)
{
if(typeof previousValue[parts[i]] == 'undefined')
return -1;
else
previousValue = previousValue[parts[i]];
}
return previousValue;
}
var myValue= get(o,'filters.animals.dogs.myDog');
alert(myValue);

JS: How to return 'undefined' instead of throwing error 'cannot read property x of undefined'

What is the best way to have js return undefined rather than throw an error when a parent property does not exist?
Example
a = {}
b = a.x.y.z
// Error: Cannot read property 'value' of undefined
// Target result: b = undefined
You have to check for the existence of each property:
var b;
if (a.x && a.x.y && a.x.y.z) {
b = a.x.y.z
}
Or, simliar to another poster's "safeGet" function:
var get = function (obj, ns) {
var y = ns.split('.');
for(var i = 0; i < y.length; i += 1) {
if (obj[y[i]]) {
obj = obj[y[i]];
} else {
return;
}
}
return obj;
};
Use:
var b = get(a, 'x.y.z');
try {
a = {}
b = a.x.y.z
}
catch (e) {
b = void 0;
}
I would go for slightly verbose:
var b = ((a.x || {}).y || {}).z
you could write a safeGet helper function, something like:
edited for drilldown as suggested in comments by arcyqwerty
var getter = function (collection, key) {
if (collection.hasOwnProperty(key)) {
return collection[key];
} else {
return undefined;
}
};
var drillDown = function (keys, currentIndex, collection) {
var max = keys.length - 1;
var key = keys[currentIndex];
if (typeof collection === 'undefined') {
return undefined;
}
if (currentIndex === max) {
return getter(collection, key);
} else {
return drillDown(keys, currentIndex + 1,
getter(collection, key));
}
};
var safeGet = function (collection, key) {
if (key.indexOf(".") !== -1) {
return drillDown(key.split("."), 0, collection);
} else {
return getter(collection, key);
}
};
a = { x: 1 };
b = safeGet(a, 'x.y.z');
http://jsfiddle.net/YqdWH/2/

(Un)Set nested array values by string input

I have a function like this:
Session.get = function(key) {
if (!window["_SESSION"] || typeof key == 'undefined') {
return window["_SESSION"] || {};
}
if (key.indexOf('.') === -1) {
return window["_SESSION"][key] || {};
}
var keyArr = key.split('.'), val = window["_SESSION"];
for ( var i = 0; i < keyArr.length; i++) {
if (typeof val[keyArr[i]] === 'undefined') {
return null;
}
val = val[keyArr[i]];
}
return val;
}
This function allows me to get nested values without temporary variable outside of the function. Example Session.get('var.nestedvar') is returns value of window[_SESSION']['var']['nestedvar'].
Bat how can I (un)set variables like so? Tried to delete val; but didn't work.. How do the javascript references work? Does anybody know any alternative to accomplish similiar functionality?
You can delete by parent like this:
[10:00:00.380] a = {'root': {'home':'~'}}
[10:00:00.385] ({root:{home:"~"}})
--
[10:00:09.625] b = a['root']
[10:00:09.631] ({home:"~"})
--
[10:00:20.569] delete b['home']
[10:00:20.573] true
[10:00:21.684] a
[10:00:21.688] ({root:{}})
You can use a slight modification of your existing code, like this:
Session.delete = function(key) {
if (!window["_SESSION"] || typeof key == 'undefined') {
return false;
}
if (key.indexOf('.') === -1) {
if (key) {
delete key;
return true;
}
}
var keyArr = key.split('.'), val = window["_SESSION"];
var keyDepth = keyArr.length;
for ( var i = 0; i < keyDepth-1; i++) {
if (typeof val[keyDepth] === 'undefined') {
return null;
}
val = val[keyDepth];
}
if (val[keyDepth-1]) {
delete val[keyDepth-1];
return true;
}
return false;
}

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