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Re: Push object to array syntax

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antony@maxwelllucas.com wrote:
> I'm struggling with the syntax when trying to create an array of 
> objects.
> 
> I have a JSON feed which has a boat load of data in a don't need 
> so I'm just grabbing the relevant values and creating a new array 
> (it's to be using in a leaflet.js map btw)

It's all right to reduce the data, but you really should show us
the structure of the data you receive.  I'm making a guess and
assuming that the callback to Datafeed.query receives an array of
objects, but your sample code (assuming that the `_` is something
like Underscore or LoDash) would work with certain other structures
as well, in which case, my suggestion might not help.

> The format I need is:
>     markers: { 
>       marker-name-1:{"lat":32.0852999,"lng":34.7817676}, 
>       marker-name-2:{"lat":30.0444196,"lng":31.2357116}
>     }

I assume you need an object wrapping that up:

    {
      markers: { 
        marker-name-1:{"lat":32.0852999,"lng":34.7817676}, 
        marker-name-2:{"lat":30.0444196,"lng":31.2357116}
      }
    }

If not, I'm not quite sure what you mean.

This code might do what you 

    var newArray = Datafeed.query(function(response) {
      return {markers: response.map(function(rows) {
        var obj = {};
        obj[rows.title] = {
            lat: +rows.custom_fields._wp_geo_latitude,
            lng: +rows.custom_fields._wp_geo_longitude
        };
        return obj;
      })};
    });

This is making the assumption that `Datafeed.query` returns
to you the result of your callback function.  If not, you
would have to structure it slightly differently:

    var newArray;
    Datafeed.query(function(response) {
      newArray = {markers: response.map(function(rows) {
        var obj = {};
        // ...

And if you need this code to run in environments that don't support
`Array.prototype.map`, you would need either to replace the `map`
call with a library `map` or shim it.  A reasonable shim is found 
on MDN [1].  A `map` from Underscore or LoDash would be used like
    
      return {markers: _.map(response, function(rows) {
        /* ... */
      });

The `map` in the Ramda [2] library I've been working on puts the
list after the function, so would work like this:

      return {markers: R.map(function(rows) {
        /* ... */
      }, response);


  [1]: <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/Reduce#Polyfill>
  [2]: <https://github.com/CrossEye/ramda>

HTH,

  -- Scott

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Thread

Push object to array syntax antony@maxwelllucas.com - 2014-07-25 15:04 -0700
  Re: Push object to array syntax Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-07-26 11:08 +0200
  Re: Push object to array syntax Scott Sauyet <scott.sauyet@gmail.com> - 2014-07-27 10:52 -0700
    Re: Push object to array syntax Scott Sauyet <scott.sauyet@gmail.com> - 2014-07-27 18:24 -0700
      Re: Push object to array syntax antony@maxwelllucas.com - 2014-07-28 07:06 -0700
  Re: Push object to array syntax lingmaaki@gmail.com - 2014-10-29 00:29 -0700
    Re: Push object to array syntax John Harris <niam@jghnorth.org.uk.invalid> - 2014-10-29 15:23 +0000
      Re: Push object to array syntax "Christoph M. Becker" <cmbecker69@arcor.de> - 2014-10-29 17:34 +0100

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