Alright, so I have an m-array (Or an array of arrays in actionscript as it doesn't really have m-arrays) and each array in the superarray has a number of objects created at different times in it. I want to sort the superarray by in descending order of the value of the "time" paramater of the object at index 0 in each subarray.
I've tried
superarray.sortOn([0].time, Array.DESCENDING);
and
superarray.sortOn("0.time", Array.DESCENDING);
but this doesn't seem to work. Any suggestions? Will I just have to write my own sort function to do this? If so what's the best way to go about it?
Try using the Array.sort function passing a compare function. Something like this:
var superarray:Array = [
[{time:900}, {time:715}, {time:655}],
[{time:450}, {time:333}, {time:100}],
[{time:999}, {time:75}, {time:30}]
];
var sorted:Array = superarray.sort( function(A:Array,B:Array):int {
return ObjectUtil.numericCompare(A[0].time, B[0].time);
});
Related
I need to implement a download feature. It will read the data in the react-data-grid (adazzle), respecting the current columns, filters and sort, and create an array json (or comma separated strings) I can then pass to the react-csv module.
I have a data structure populated from the backend but it is not filtered nor sorted. I need to be able to ask the grid for it's data on a row-by-row basis. Can anyone point me in the right direction?
Without code or some context, I can't answer with certainty...
You supply the rowGetter prop with the collection to display, or the method to get the rows to display...I'm thinking if you filtering, then most likely you've got some sort of mechanism supporting that... Either way, you can use this property's value somehow to get exactly what you see in the grid.
If you literally want to interrogate the grid, you could try adding a reference to the grid, and then see if you can ask it for the row data. I can't remember with certainty that I saw a rows prop in the grids available props via the ref, but I imagine you should be able to (**,)
...
handleExport = async => {
const exportRows = rows;
// const exportRows = getRows(initialRows, filters);
// const exportRows = this.state.gridref.CurrentRows DISCLAIMER:CurrentRows is just for giving the idea... check out the ref yourself to see if it's possible to get the rows via the grid refs props.
downloadCSV( exportRows )
}
...
<ReactDataGrid
ref={input => {this.state.gridref = input}}
columns={columns}
rowGetter={i => rows[i]} // or maybe rowGetter={i => getRows(initialRows, filters)[i]}
rowsCount={rows.length}
onGridSort={(sortColumn, sortDirection) =>
setRows(sortRows(initialRows, sortColumn, sortDirection))
}
/>
I've only ever [set / initialised] the this.state.gridRef prop in my constructor, but I guess you could also [set / initialise] it in your componentDidMount as well...
initialise like this:
this.state.gridRef = React.createRef()
I try to access to my data json file:
[{"id":1,"name":"Maria","project":[{"id":5,"name":"Animals"},{"id":6,"name":"Cats"}]}
This is my approach:
data[0].name;
But like this I get only the result:
Animals
But I would need the result:
Animals, Cats
You are accessing only the name property of 0th index of project array.
To access all object at a time you need to loop over the array.
You can use Array.map for this.
var data = [{"id":1,"name":"Maria","project":[{"id":5,"name":"Animals"},{"id":6,"name":"Cats"}]}]
var out = data[0].project.map(project => project.name).toString()
console.log(out)
If that's your actual data object, then data[0].name would give you "Maria". If I'm reading this right, though, you want to get all the names from the project array. You can use Array.map to do it fairly easily. Note the use of an ES6 arrow function to quickly and easily take in the object and return its name.
var bigObject = [{"id":1,"name":"Maria","project":[{"id":5,"name":"Animals"},{"id":6,"name":"Cats"}]}];
var smallObject = [{"id":5,"name":"Animals"},{"id":6,"name":"Cats"}];
console.log("Getting the names from the full array/data structure: "+bigObject[0].project.map(obj => obj.name))
console.log("Getting the names from just the project array: "+smallObject.map(obj => obj.name))
EDIT: As per your comment on the other answer, you said you needed to use the solution in this function:
"render": function (data, type, row) {if(Array.isArray(data)){return data.name;}}
To achieve this, it looks like you should use my bottom solution of the first snippet like so:
var data = [{"id":5,"name":"Animals"},{"id":6,"name":"Cats"}];
function render(data, type, row){
if(Array.isArray(data)){
return data.map(obj => obj.name);
}
};
console.log("Render returns \""+render(data)+"\" as an array.");
I'm working with PHP, I have a json structure which looks like that :
{
"events": [
{
"timestamp": 1468774519,
"id": 75964,
},
{
"timestamp": 1468771410,
"id": 24891,
},
// etc
I need to fetch 5 events in a row, but starting from one specific id, so my first idea is to loop every event from the beginning and check if the id is the offset i'm looking for, and then when i get it i can loop the next 5 events.
But is there a better way to do so ? It could possibly loop through hundreds of events so maybe there's a better way to get there ? thanks
Since the ids aren't in numeric order, you can't use a binary search, so you need to use a sequential search. Here's an example in JavaScript. Also note this code assumes the id is present and there are at least four more events after it in the array.
var index = 0;
var id = 12345; // for example
var json = {...}; // whatever that object was
while(json.events[index].id!=id) {
index++;
}
// found the one, do something with the next five
for(var i=0; i<5; i++) {
var event = json.events[index+i];
// do something
}
In my opinion, you can only take one loop over the events with a filter event.id >= theId,and then check if the filtered array contains theId. if you get it, you can sort this smaller array and take the 5 events.
First I would make a key:value hash object (a lookup object), where the key would be the id from your structure, and the value would be the reference to the event. As a result, you iterate over the structure only once and then get all the events from the lookup structure, by just accessing them by their keys.
You could sort it as well(ideally, you could get it already sorted by id from your source of data) and then use a binary search algorithm.
I have two arrays, array1 and array2. I need to compare both of these arrays and I want to create a third array, array3, whereby it shows the elements that are in array2, that are not in array1.
This is what I have so far:
my_buckets = Model.select("DISTINCT bucket").where(["my_id = ?", params[:user]])
all_buckets = Model.select("DISTINCT bucket").collect { |x| x.bucket }.uniq.compact
buckets_not_in_my_buckets = Model.select("DISTINCT bucket").where(["bucket NOT IN (?)", my_buckets]).collect { |x| x.bucket }.uniq.compact
For some reason, the buckets_not_in_my_buckets is always returning an empty array ([]). Is there a better way to approach this? Any help would be appreciated.
buckets_not_in_my_buckets = all_buckets - my_buckets
I'm assuming that you have the eql? operator on your buckets object working how you'd like.
Please see the Array docs for more detail.
Let's say I have a JSON array of data, something like:
[ {"name":"parijat","age":28},
{"name":"paul","age":28},
{"name":"steven","age"27},
...
]
that is part of my model, and this model is setup like this:
App.UserRoute = Ember.Route.extend({
model:function(){
return App.User.FIXTURES ; // defined above
}
});
I want to get the unique ages from this JSON array and display them in my template, so I reference the computed properties article and read up a little on how to enumerate Ember Enumerables, to eventually get this:
App.UserController = Ember.ArrayController.extend({
ages:function(){
var data = this.get('content');
var ages = data.filter(function(item){
return item.age;
});
}.property('content');
});
Now the above piece of code for controller is not correct but the problem is that it doesn't even go into data.filter() method if I add a console.log statements inside. IMO, it should typically be console logging as many times as there exist a App.Users.FIXTURE. I tried using property('content.#each') which did not work either. Nor did changing this.get('content') to this.get('content.#each') or this.get('content.#each').toArray() {spat an error}.
Not sure what to do here or what I am completely missing.
Filter is used for reducing the number of items, not for mapping.
You can use data.mapBy('age') to get an array of your ages:
ages:function(){
return this.get('content').mapBy('age');
}.property('content.#each')
or in your handlebars function you can just use the each helper:
{{#each item in controller}}
{{item.age}}
{{/each}}