Basically I am transforming a JSON result into html and using $.each it iterate through multiple keys. For example, I am pulling back facebook posts and iterating through the likes in that post.
The problem lies in the fact that when there are multiple "likes" everything works great! although when there is only 1 "like" the "source" key is removed from the result set and my javascript breaks because I expect it to be there. Any idea why the $.each is skipping a level for single nodes? The following is my code:
* JQUERY **
$.each(post.likes.item, function(i, like){
$(currentpost).find('div.cc_likes').append(like + ',');
console.log(like)
});
* JSON RESULT **
* Single Like
likes": {
"item": {
"source": {
"cta": "Mary Smith",
"url": "http:\/\/www.facebook.com\/",
"photo": {
"image": "https:\/\/graph.facebook.com\/"
}
}
},
Result in console:
Object
cta: "MaryAnn Smith"
photo: Object
url: "http://www.facebook.com/"
* Multiple Likes
"likes": {
"item": [
{
"source": {
"cta": "Bobby Carnes Sr.",
"url": "http:\/\/www.facebook.com",
"photo": {
"image": "https:\/\/graph.facebook.com\"
}
}
},
{
"source": {
"cta": "Jenna Purdy",
"url": "http:\/\/www.facebook.com\",
"photo": {
"image": "https:\/\/graph.facebook.com\"
}
}
},
{
"source": {
"cta": "Kevin Say",
"url": "http:\/\/www.facebook.com\",
"photo": {
"image": "https:\/\/graph.facebook.com\"
}
}
}
],
"count": "10",
"count_display": "10"
},
Result in console:
Object
source: Object
cta: "Kevin Smith"
photo: Object
url: "http://www.facebook.com/"
Since $.each() needs an array or array like object as argument, before using the object post.likes.item check if it is an array of not.
Following code will always pass an array to jQuery -
$.each([].concat(post.likes.item), function(i, like){
$(currentpost).find('div.cc_likes').append(like + ',');
console.log(like)
});
Explanation
[] is an empty array in JavaScript. Every array in JavaScript has a concat method.
[].concat(obj) concats obj to the empty array and returns an array.
if obj is not an array, result is [obj] which is an array with one item.
if obj is an array, then result is a deep copy of obj which is already an array.
More about concat method
if ( isArray ) {
for ( ; i < length; i++ ) {
value = callback.call( obj[ i ], i, obj[ i ] );
if ( value === false ) {
break;
}
}
} else {
for ( i in obj ) {
value = callback.call( obj[ i ], i, obj[ i ] );
if ( value === false ) {
break;
}
}
}
That is the jquery code being run on your JSON return. What's happening is, when you are looking at multiple results, it is looping through the array, return each base level object. However, when you are running it on a single return, it is looping through the object properties(in this case, "source"), and returning the value of that property.
You have two choices here. You can either make sure single items are still put in an array, or you can do a check for single items on the client side. The way Moazzam Khan suggests is the best way to do it in most cases.
Related
I want to loop through 600+ array items in an object and find one particular item based on certain criteria. The array in the object is called "operations" and its items are arrays themselves.
My goal is to get the index of operation's array item which has the deeply nested string "Go".
In the sample below this would be the first element. My problem is that I can check if an array element contains "call" and "draw" but I don't know how to test for the nested dictionary "foobar". I only have basic JavaScript available, no special libraries.
let json = {
"head": {},
"operations": [
[
"call",
"w40",
"draw",
{
"parent": "w39",
"style": [
"PUSH"
],
"index": 0,
"text": "Modify"
}
],
[
"call",
"w83.gc",
"draw",
{
"foobar": [
["beginPath"],
[
"rect",
0,
0,
245,
80
],
["fill"],
[
"fillText",
"Go",
123,
24
],
[
"drawImage",
"rwt-resources/c8af.png",
]
]
}
],
[
"create",
"w39",
"rwt.widgets.Menu",
{
"parent": "w35",
"style": [
"POP_UP"
]
}
],
[
"call",
"w39",
"draw",
{
"parent": "w35",
"style": [
"POP_UP"
]
}
]
]
};
let index = "";
let operationList = json.operations;
for (i = 0; i < operationList.length; i++) {
if (operationList[i].includes('call') && operationList[i].includes('draw')) //missing another check if the dictionary "foobar" exists in this element )
{
index = i;
}
}
document.write(index)
I'll preface by saying that this data structure is going to be tough to manage in general. I would suggest a scheme for where an operation is an object with well defined properties, rather than just an "array of stuff".
That said, you can use recursion to search the array.
If any value in the array is another array, continue with the next level of recursion
If any value is an object, search its values
const isPlainObject = require('is-plain-object');
const containsTerm = (value, term) => {
// if value is an object, search its values
if (isPlainObject(value)) {
value = Object.values(value);
}
// if value is an array, search within it
if (Array.isArray(value)) {
return value.find((element) => {
return containsTerm(element, term);
});
}
// otherwise, value is a primitive, so check if it matches
return value === term;
};
const index = object.operations.findIndex((operation) => {
return containsTerm(operation, 'Go');
});
I am working with an API right now and I am using details[5].Value to target information in the following format:
details:
"value":[
{
"ID": "6",
"Name": "Links",
"Value": "URL"
},
{
"ID": "7",
"Name": "Other",
"Value": "URL"
}
etc
]
The problem is that the location inside of the JSON response is likely to change in the future, making my code obsolete and as the url has the potential to change as well, I cannot target that.
I want a way to target the value of url, mostly, because of this, by the value of the "Name" property. However, if I use something like
_.where(details, { Name: "Links" }).Value
It comes back as undefined. I am not sure if there would be another way to get to the information?
There are a couple points of confusion here.
_.where returns an array:
Looks through each value in the list, returning an array of all the values that contain all of the key-value pairs listed in properties.
so your _.where(details, obj).Value will (almost) always give you undefined because an array is unlikely to have a Value property. _.findWhere on the other hand does return a single value:
Looks through the list and returns the first value that matches all of the key-value pairs listed in properties.
Secondly, your details appears to look like:
let details = {
value: [
{ ID: '6', Name: 'Links', Value: 'URL' },
{ ID: '7', Name: 'Other', Value: 'URL' },
...
]
}
so you don't want to search details, you want to search details.value.
Putting them together:
_(details.value).findWhere({ Name: 'Links' }).Value
or
_.findWhere(details.value, { Name: 'Links' }).Value
You could use Array.prototype.find (or Array.prototype.filter if you're looking for all matches) and write your own callback but you already have Underscore available so why bother? Furthermore, Backbone collections have findWhere and where methods and there are advantages to matching Backbone's overall terminology.
Take a look at this mini function. Let me know if there is something wrong
Update
This is the ES5 Version
function f(key, value, array){
return array.value.filter(function(sub_array){
return sub_array[key] == value;
});
}
This is the ES6 Golfed Version
f=(k,v,a)=>a.value.filter(_=>_[k]==v)
//This is your JSON
var details = {
value: [
{
"ID": "6",
"Name": "Links",
"Value": "URL"
},
{
"ID": "7",
"Name": "Other",
"Value": "URL"
}
]
}
// Short code
f=(k,v,a)=>a.value.filter(_=>_[k]==v)
// f is the function name
// Recives k = array key, v = value, a = array
// filter by the given key and value
// return the result as an array
console.log(f('Name', 'Links', details))
An alternative is using the Javascript built-in function find to get a specific object within an array.
This alternative allows you to pass either an object or a string.
If the byThis parameter is an object, the whole set of key-values must match with the key-values of every object within the target array.
Otherwise, if byThis is a string every object will be treated as string to make the necessary comparison.
let details = { "value": [{ "ID": "6", "Name": "Links", "Value": "URL" }, { "ID": "7", "Name": "Other", "Value": "URL" }]};
let findBy = (array, byThis) => {
return array.find(o => {
if (typeof byThis === 'object') return Object.keys(byThis).every(k => o[k] === byThis[k]);
else if (typeof byThis === 'string') return o.toString() === byThis;
});
}
let found = findBy(details.value, {Name: "Links"});
console.log(found);
.as-console-wrapper { max-height: 100% !important; top: 0; }
I want to dynamically delete json object which contains empty array. I've found this link similar question here. But it doesn't work for me in my case.
Suppose I have a JSON object:
{"op":"1","parameters":[{"op":"2-1","parameters":[]},{"op":"2-2","parameters":[1,2]}]}
I've wrote a sample code to do the stuff recursively:
function removeEmptyArray(cJSON){
if(!cJSON)
return cJSON;
for(var i=cJSON.parameters.length-1;i>=0;i--){
if(!(cJSON.parameters[i].parameters instanceof Array))
continue;
if(cJSON.parameters[i].parameters.length==0){
cJSON.parameters.splice(i,1);
}else{
cJSON.parameters[i] = removeEmptyArray(cJSON.parameters[i]);
}
}
return cJSON;
}
the expect result is {"op":"1","parameters":[{"op":"2-2","parameters":[1,2]}]}, the code works fine.
but when I have this obj:
{"op":"1","parameters":[{"op":"2-1","parameters":[{"op":"3-1","parameters":[]}]},{"op":"2-2","parameters":[1,2,3]}]}
The output is {"op":"1","parameters":[{"op":"2-1","parameters":[]},{"op":"2-2","parameters":[1,2,3]}]}
Obviously it does not dynamically remove the json obj whose "op" is "2-1".
So how to solve it in an elegant way, using pure javascript?
You could use a breadth first algoritm, which look first in the depth and then deletes, if necessary.
function isNotEmpty(object) {
if (Array.isArray(object.parameters)) {
object.parameters = object.parameters.filter(isNotEmpty);
return object.parameters.length;
}
return true;
}
var object = { "op": "1", "parameters": [{ "op": "2-1", "parameters": [{ "op": "3-1", "parameters": [] }] }, { "op": "2-2", "parameters": [1, 2, 3] }] };
isNotEmpty(object);
console.log(object);
I am working Angular js project, I am getting form server response is JSON Object. That JSON Object contains nested Objects and Arrays. for every time i need write lot coding getting the value of key
Ex:
{
"mapData": {
"data": [
{
"key": "name",
"value": "abc"
},
{
"key": "name",
"value": "bcd"
},
{
"key": "name",
"value": "vbc"
}
]
}
}
what i was tried example is so many times, it is not related above example.
for(var key in object) {
if(key=="Id"){
Id= object[key].fieldValue;
secondData.forEach(function(item){
for(var innerItem in item){
if(innerItem =="Id"){
if(Id==item[innerItem].fieldValue){
FinalData.push(item);
}
}
}
});
}
}
Is there any way generic way Instead of writing every time for for loop and For Each loop.
could you please suggest any things
Thanks in advance
mapData.data[i].key will return your key value. i is index of your data array you can easily iterate data by
for(var i =0;i<mapData.data.length;i++){}
I am trying to parse the following JSON with jQuery and get each id value. Can anyone advise?
[
{
"id": "1",
"name": "Boat"
},
{
"id": "2",
"name": "Cable"
}
]
So far I have:
$.each(test, function(i,item){
alert(item);
});
But that simply lists every value. How can I
That'll list every object in your array, to get the id property of the one you're on, just add .id like this:
$.each(test, function(i,item){
alert(item.id);
});
If test is a string containing JSON, you can parse it with jQuery.parseJSON, which will return a JavaScript object.
If test is written like this:
var test = [
{
"id": "1",
"name": "Boat"
},
{
"id": "2",
"name": "Cable"
}
];
...it already is a JavaScript object; specifically an array. jQuery.each will loop through each array entry. If you want to loop through the properties of those entries as well, you can use a second loop:
$.each(test, function(outerKey, outerValue) {
// At this level, outerKey is the key (index, mostly) in the
// outer array, so 0 or 1 in your case. outerValue is the
// object assigned to that array entry.
$.each(outerValue, function(innerKey, innerValue) {
// At this level, innerKey is the property name in the object,
// and innerValue is the property's value
});
});
Live example