Cusom Queries in Ionic2 about backand-ionic2-starter HOT 6 CLOSED

The way to do it is demonstrated in this function from the file app/services/backandServices.ts:

 public filterItems(query) {
        let filter = 
            [
              {
                fieldName: 'name',
                operator: 'contains',
                value: query
              }
            ]
        ;

        return this.http.get(this.api_url + '/1/objects/todo?filter=' + encodeURI(JSON.stringify(filter)), 
            {
                headers: this.authHeader
            })
            .retry(3)
            .map(res => res.json().data);
    }

As you can see in the CRUD tab as we filter with a search window.

from backand-ionic2-starter.

That's great thanks, so how would this work with a location based query such as in the Backand documentation:

{
      "object": "restaurants",
      "q": {
         "location" : { "$withinMiles" : [[37.8019859, -122.4414805], 25] }
      }
  }

Could you use this same filter logic against an /1/objects/restaurants object with the fieldName: 'location' if so what would the operator and value attributes look like

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The filter parameter in GET objects '/1/objects/restaurants' can work in two ways

1. One way is with field, operator and value array like this
   [{fieldName: 'name',operator: 'contains',value: 'something'}]
2. The other is with a NoSQL condition, something like this
   {
   "object": "restaurants",
   "q": {
   "name" : { "$like" : 'something' }
   }
   }
   both ways are equivalent.
   however for location you must only use the NoSQL way like in the example above and should look like this:

public filterLocation(point, miles) {
        let withinMiles = 
       {
              "q": {
                   "location" : { "$withinMiles" : [point, miles] }
                }
        }

        return this.http.get(this.api_url + '/1/objects/todo?filter=' + encodeURI(JSON.stringify(withinMiles)), 
            {
                headers: this.authHeader
            })
            .retry(3)
            .map(res => res.json().data);
    }

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Thanks @relly and @kornatzky that's sorted it 👍

One last question; is there any way of sorting a $withinMiles query by distance from the point ASC or DESC?

Cheers

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You can use Backand queries for that. Backand Query works for both SQL and NoSQL syntax.
You can read more at the docs.
Here is an example for the SQL that you may use:

SELECT * FROMrestaurants WHERE (ST_Distance (restaurants.location, ST_GeomFromText('POINT( 37.8019859 -122.4414805 )') ) <= 25 /(69)) ORDER BY ST_Distance (restaurants.location, ST_GeomFromText('POINT( 37.8019859 -122.4414805 )') )

It is a basic suggestion that I am sure you will improve. There is a lot of information how to work with MySQL and GEO Point, That is what we use in Backand.
I also suggest that you will send the point values as parameters to the query
You can see it in the docs for NoSQL but it is the same as for SQL

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That's brilliant thanks @relly

It brings me back to my original point however as to how one executes a custom query, with input parameters, in an ionic2 app? Unfortunately I can't find any docs around this.

Many thanks

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