How to use @mapbox/mapbox-gl-style-spec - 10 common examples

function getPropertyFromFilter(filter, properties) {
  if (styleSpec.expression.isExpression(filter)) {
    getPropertyFromExpression(filter, properties);
  }

  // Warning: Below code should put in to an else conditions,
  // but since the `isExpression` can not tell it is a expression or filter syntax I put it outsied the else
  // this could reduce the performance or cause some potential bugs, we must keep an eye on this.

  // else {
  let subFilter = [];
  for (let i = 0; i < filter.length; i++) {
    if (typeof filter[i] === 'object' && filter[i] instanceof Array) {
      subFilter.push(filter[i]);
    }
  }

  if (subFilter.length > 0) {

// - special properties: `mapbox_clip_start`, `mapbox_clip_end`
    if (typeof value === 'string') {
      // if the value is string try to get property name from `xx{PropertyName}xx` like.
      // the /{[^}]+}/ig return all the value like {xxx}
      // eg 'a{hello}badfa' => ['{hello}']
      // eg 'a{hello}ba{world}dfa' => ['{hello}','{world}']
      let preProperties = value.match(/{[^}]+}/ig);
      preProperties && preProperties.forEach(item => {
        properties.push(item.slice(1, -1));
      });
    } else if (typeof value === 'object' && typeof value.property === 'string') {
      // - legacy functions with `property`
      properties.push(value.property);
    } else {
      // test isExpression from sytleSpec
      if (styleSpec.expression.isExpression(value)) {
        // TODO: now we implement this by ourself in vtshavem, we need to talk with ‘style spec’ member to see if there have a official method to get used property, to make this can be synchronized with the expression update.
        getPropertyFromExpression(value, properties);
      } else {
        // otherwise continual loop;
        getPropertyFromLayoutAndPainter(value, properties);
      }
    }
  })
}

export function filterFeatures(features, filter, inverse = true) {
    const new_features = [];

    // the createFilter function is from mapbox!
    // uses the mapbox gl style filters.
    let filter_function = function() { return true; };

    if (filter !== undefined && filter !== null ) {
        filter_function = createFilter(['all'].concat(filter));
    }

    for(const feature of features) {
        if(inverse !== filter_function(feature)) {
            new_features.push(feature);
        }
    }

    return new_features;
}

.then(function(data) {
          var json = simpleExpr.compile(data)

          var out = mgl.expression.createExpression(json, {})
          var result = out.value.evaluate(globalOpts, {
            id: argv["feature-id"],
            type: argv["feature-type"],
            properties: featureOpts
          })

          console.log(result);
          process.exit(0);
        })
        .catch(handleError)

/*
Generates the list of paint and layout properties from the Mapbox-GL-JS style spec.
Should be run when new properties are added to that spec.
*/

const v8 = require('@mapbox/mapbox-gl-style-spec/reference/v8.json');
const fs = require('fs');
const out = {
    paints: [],
    layouts: []
};
Object.keys(v8)
    .filter(x => /^paint_/.test(x))
    .forEach(key => out.paints.push(...Object.keys(v8[key])));

Object.keys(v8)
    .filter(x => /^layout_/.test(x))
    .forEach(key => out.layouts.push(...Object.keys(v8[key])));
    
out.paints = Array.from(new Set(out.paints));
out.layouts = Array.from(new Set(out.layouts));
fs.writeFileSync('keys.json', JSON.stringify(out));

/*
Generates the list of paint and layout properties from the Mapbox-GL-JS style spec.
Should be run when new properties are added to that spec.
*/

const v8 = require('@mapbox/mapbox-gl-style-spec/reference/v8.json');
const fs = require('fs');
const out = {
    paints: [],
    layouts: []
};
Object.keys(v8)
    .filter(x => /^paint_/.test(x))
    .forEach(key => out.paints.push(...Object.keys(v8[key])));

Object.keys(v8)
    .filter(x => /^layout_/.test(x))
    .forEach(key => out.layouts.push(...Object.keys(v8[key])));
    
out.paints = Array.from(new Set(out.paints));
out.layouts = Array.from(new Set(out.layouts));
fs.writeFileSync('keys.json', JSON.stringify(out));

render() {
    return 
      
    
  }
}

render() {
    return 
       [src, src])}
      />
    
  }
}

render() {
    return 
      
    
  }
}

render() {
    return 
      
    
  }
}