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geostyler / geostyler-openlayers-parser

GeoStyler Style Parser implementation for OpenLayers styles
BSD 2-Clause "Simplified" License
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Handle RegEx with flags #702

Closed geographika closed 1 year ago

geographika commented 1 year ago

Description

A MapServer class such as in the tests here :

  CLASS
    EXPRESSION {bus,bank}

Converts to the following GeoStyler style (see here):

    filter: [
      '==', {
        name: 'strMatches',
        args: [{
          name: 'property',
          args: ['name']
        }, '/(bus|bank)/']

When this is converted to an OpenLayers style function using the code in OlStyleUtil

      case 'strMatches':
        return new RegExp(args[1] as string).test(args[0] as string);

The forward slashes are escaped and no features are matched:

r = new RegExp(args[1])
/\/(bus|bank)\//

// this is what we want
r = new RegExp(/(bus|bank)/)
/(bus|bank)/

// but as a string is passed they are escaped:

r = new RegExp('/(bus|bank)/')
/\/(bus|bank)\//

This pull request strips the start and trailing '\' from the string. As discussed with @jansule there may be issues if flags are stored in GeoStyler regex strings e.g. /pattern/gmi. To support this requires passing 'gmi' to the flags parameter of the RegEx constructor e.g. new RegExp('pattern', 'gmi'). This is handled in this pull request.

The following approach works for all cases r = new RegExp(eval(args[1])) but using eval is problematic. Initially I thought String.raw was an option but this doesn't work correctly.

Related issues or pull requests

Originally added as an issue at https://github.com/geostyler/geostyler-mapfile-parser/issues/247

Pull request type

Do you introduce a breaking change?

Checklist