Before I describe the issue, please forgive any incorrect terms and accidental references to objects instead of arrays and vice-versa, I'm not completely up to speed on this but working my way through it.
I have the following array in PHP saved as a session variable:
{"CategoryF":[],"CategoryA":["Life","There","People","Land","Family"],"CategoryC":["Various"]}
After a thumbnail in a grid of images is dragged into a new order, it execute a function in javascript and makes a call to a PHP script using ajax. It currently only retrieves the most up to date version of a session array. It will later progress to make the necessary steps to save the updated array back to session variable and database:
var sorty = Sortable.create(thumbcontainer, {
animation: 250,
draggable: "img",
dataIdAttr: 'id',
onUpdate: function (/**Event*/evt) {
var orderList = sorty.toArray();
var catsArray =
$.ajax({
type: 'POST',
url: 'includes/proc_cats.php',
dataType: 'json'
}).done(function(returnedCatsArray) {
console.log(returnedCatsArray);
});
console.log('Dragged. Order is: ' + orderList);
}
});
proc_cats.php
<?php
// Access the existing session
session_start();
// $catsArray is a session variable, in the format as above.
$catsArray = json_encode($_SESSION['categoriesPics']);
echo $catsArray;
?>
The var orderList will produce a string with the order of each thumbnail by id, separated by comma: '42,35,95,12,57'.
The console shows the PHP array as a javascript array fine but in a different order. I want to be able to insert the string containing the orders into the array and save it back into the database. It will associate with its relevant category, similar to:
{"CategoryF":[],"CategoryA":["Life":["23,74,47,12,86,83,12"],"There","People","Land","Family"],"CategoryC":["Various"]}
But can't lose the order as other parts of the site reference the array by indices using array_keys. The console produces:
Object:
CategoryA:Array[0]
CategoryC:Array[0]
CategoryF:Array[5]
Have I missed something? I believe that the overall array is an object rather than an array because it didn't have any index whereas the subcategories did and they get presented as an array. array_keys in PHP have made it straightforward enough to work around any indexing problems up until now on the PHP side in other areas of the site but I'm wondering if the solution for the javascript side is something as straightforward? The subcategories currently have indices only because I've yet to associate and orderList with them so I'm not trying not to backtrack and build an index for the array as it's going to get difficult (unless there's a simple way to do this that I've overlooked).
(This is a more specific version of a question I asked an hour ago that I've now deleted for being too broad).
I believe you have a slight confusion based on the terms 'associative array' and 'array'. A php associative array corresponds to a javascript object. returnedCatsArray should be accessed similar to $catsArray. ie. with keys. If one of those keys returns an an actual array, you can then index into it.
php array_keys would be Object.keys(returnedCatsArray) in javascript.
From further research it appears this is just not doable. So the best way to do this may be to provide an order array alongside my category array.
If I add the additional code of:
$parentCatOrder = array_keys($catsArray);
in my proc_cats.php script I have a concise way of generating an index reference for my original array on the fly each time. This produces an array similar to:
$parentCatOrder = {'categoryF', 'categoryA', 'categoryC'};
which has an index that I can refer to that keeps its order. So $parentCatOrder[2] will always produce 'categoryC' unless I've changed the array myself.
I then return both arrays to javascript using the following:
$return_data['catsarray'] = $catsArray;
$return_data['parentcatsorder'] = $parentCatOrder;
// Encode it back into a JSON object before sending
echo json_encode($return_data);
In javascript I can reference returnedCatsArray.catsarray[returnedCatsArray.parentcatsorder[1]][3] if I'm working with an index of 1-3 and guarantee this will produce the same result for every user unless the array has been changed by the user.
Related
I am new to javascript and every time i try learning it, I just end up in an immense amount of frustration and disgust ! No offense, but this is my opinion or perhaps I am too stupid to not understand how it works at all.
I have a simple requirement. I have a pretty deeply nested dictionary (which is what it is called in many backend languages) at hand. To be more specific it is the raw text of a postman collection. The collection itself could have multiple nested directories.
Now all I want to do is to be able to parse this dictionary and do something with it recursively.
For example, if I had to do the same in python I would do it as simply as :
def createRequests(self, dic):
total_reqs = 0
headers = {}
print type(dic)
keys = dic.keys()
if 'item' in keys:
print "Folder Found. Checking for Indivisual request inside current folder . . \n"
self.item_list = dic.get('item')
for each_item in self.item_list:
self.folder.append(self.createRequests(each_item))
else:
print "Found Indivisual request. Appending. . . \n"
temp_list = []
temp_list.append(dic)
self.requestList.append(temp_list)
return self.requestList
where dic would be my dictionary that I want to parse.
Is there any simple and straight forward way to do the same in Javascript?
Let's just say all I want to do is that if I have a text file that has properly formed json data in it and whose contents have been read into dataReadFromFile and then it has been converted into a JSON as :
var obj = JSON.parse(dataReadFromFile);
is there any simple and easy way to convert this JSON to dictionary or the dataReadFromFile directly into a dictionary such that I can say something like dictioanry.keys() if I wanted a list of the keys in it.
Note that the content of the file is not fixed. It may have multiple levels of nesting, which may not be known beforehand.
I have an array in PHP that I encode to json:
$jsonOutput = json_encode($output);
Then in my javascript, I use this to parse it:
var jsonOutput = JSON.parse('<?php echo $jsonOutput; ?>');
My output looks like this in the Chrome console:
Ultimately, I have two arrays, and I'm trying to write a compare between the two to show if there are any items in the first array that aren't in the second, but I'm not sure how to reference red and orange here.
I tried console.log(jsonOutput[0]) but I get undefined.
Also, as a side note, does anyone have any good resources for reading up on arrays in javascript and all their ins-and-outs? It seems to be one aspect that I'm struggling with lately...
The problem is that your jsonOutput is an Object, so in order to access one member of the object you either have to user jsonOutput.red/jsonOutput.orange or jsonOutput["red"], jsonOutput["orange"] to access a member of the object.
More info here Access / process (nested) objects, arrays or JSON.
jsonOutput.red[0]
You have an object with two keys. Not an array.
You access those arrays using:
jsonOutput.red;
jsonOutput.orange;
I have a little bit of an issue with a JavaScript function that needs to read data from a TextFile (something JS is already limited with) and then process tha TextFile data into a MultiDimensional Array (another thing that JS doesn't nativelly suport).
With that in mind, I have a text file in this format:
1, Name, Data, Serial
2, Name, Data, Serial
3, Name, Data, Serial
And so on.
So, the objective is to get that same data and put it, like that, into an array.
I suppose that, from what I've been reading, I need an Array of an Array, segmenting the first one by lines [/n] and the second one by commas [,]. However, given the "by-default" limitations, I'm very confused at this point. I do suppose I need jQuery, however.
I tried this:
var fs = require('fs');
var array = fs.readFileSync('file.txt').toString().split("\n");
for(i in array) {
var array = fs.readFileSync('file.txt').toString().split(",");
for(f in array) {
}
}
With little success, because then I don't really know how to store it, the objective being a Multidimensional Array that Replicates the Format of the text file, so latter it could be used to search by index or instance following an user input to get results.
I really appreciate any help.
At first glance it seems like you are trying to read in a CSV file. If that is indeed the case I recommend node-csv:
http://www.adaltas.com/projects/node-csv/
https://github.com/wdavidw/node-csv
This helped me reading file to JavaScript, however this example converts retrieved data to JSON. Just looking at the format of your text file, I would assume a JSON string or Javascript object would work with your data.
Example convert to JSON
With JSON and JS objects, instead of referencing a array indexes eg. array[i][x]. you would replace [x] with .propertyName
data = {
"id": 1,
"name": "Fred"
};
//access data like this
data[i].name //will return "Fred" as i =0
to create JS object, just initialize array properties without the ""(quotation marks). accessing JS and JSON properties are done in the same way, main advantage over a multidimensional array is that you can reference an actual property name, as opposed to indexes.
I have a multidimensional array that is something like this
[0]string
[1]-->[0]string,[1]string,[2]string
[2]string
[3]string
[4]-->[0]string,[1]string,[2]string[3]string,[4]string,[5]INFO
(I hope that makes sense)
where [1] and [4] are themselves arrays which I could access INFO like myArray[4][5].
The length of the nested arrays ([1] and [4]) can varry.
I use this method to store, calculate, and distribute data across a pretty complicated form.
Not all the data thats storred in the array makes it to an input field so its not all sent to the next page when the form's post method is called.
I would like to access the array the same way on the next page as I do on the first.
Thoughts:
Method 1:
I figure I could load all the data into hidden fields, post everything, then get those values on the second page and load themm all back into an array but that would require over a hundred hidden fields.
Method 2:
I suppose I could also use .join() to concatenate the whole array into one string, load that into one input, post it , and use .split(",") to break it back up. But If I do that im not sure how to handel the multidimensional asspect of it so that I still would be able to access INFO like myArray[4][5] on page 2.
I will be accessing the arrary with Javascript, the values that DO make it to inputs on page 1 will be accessed using php on page 2.
My question is is there a better way to acomplish what I need or how can I set up the Method 2 metioned above?
This solved my problem:
var str = JSON.stringify(fullInfoArray);
sessionStorage.fullInfoArray = str;
var newArr = JSON.parse(sessionStorage.fullInfoArray);
alert(newArr[0][2][1]);
If possible, you can use sessionStorage to store the string representation of your objects using JSON.stringify():
// store value
sessionStorage.setItem('myvalue', JSON.stringify(myObject));
// retrieve value
var myObject = JSON.parse(sessionStorage.getItem('myvalue'));
Note that sessionStorage has an upper limit to how much can be stored; I believe it's about 2.5MB, so you shouldn't hit it easily.
Keep the data in your PHP Session and whenever you submit forms update the data in session.
Every page you generate can be generated using this data.
OR
If uou are using a modern browser, make use of HTML5 localStorage.
OR
You can do continue with what you are doing :)
I'm doing AJAX calls to get data from the last.fm API and decided to use JSON as return data type. So far, so good. The problem is this: I want to get the top tracks using the tag.getTopTags method from the API and it returns me a JSON that isn't sorted by popularity (even though they say it is).
So how do I sort this JSON by count property (that indicates popularity) once I have this in a variable in my code?
Here's a sample of the JSON (pardon the lack of formatting, this is from a link they give on their website). It goes like this: toptags has tag which contains an array of tags, which have name, count, etc...
Here's the method from my code that requests the top tracks (via GET with a PHP file that's on my web server - this is working fine):
var getTopTracks = function() {
$.getJSON(
settings.PHP_REQUEST_URL,
{
method: "tag.getTopTags",
api_key: settings.LASTFM_APIKEY,
format: "json",
callback: "?"
},
function(data) {
// treat data here
});
};
I know how to show the data and stuff, I'd just like to sort the data before I show it. Anyone know how to do this in a simple way?
You're going to want to use Array's built-in sort method with a comparator function passed in. In your case:
data.toptags.tag.sort(function (t1, t2) {
return t1.count - t2.count;
});
The code is pretty self-explanatory, but the way it works is by using the regular sort function provided by the Array prototype and comparing the elements within the array by the comparison function provided. So, when it does comparison checks (like is count1 > than count2?), it will instead get an object in this case and you'll specify that the difference between one tag's count and the other should give precedence to which "ranks" higher in comparison.