Mercurial > gemma
view pkg/geoserver/templates.go @ 4606:dfe9cde6a20c geoserver_sql_views
Reflect database model changes for SQL views in backend
In principle, we could use many datasources with different database
schemas, but this would imply changing GeoServer initialization,
service filtering, endpoints and eventually more. Since we do not need
it, just hard-code the schema name as a constant.
author | Tom Gottfried <tom@intevation.de> |
---|---|
date | Thu, 05 Sep 2019 12:23:31 +0200 |
parents | 152b9eb5ca47 |
children | 124a5a7fe8d6 |
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// This is Free Software under GNU Affero General Public License v >= 3.0 // without warranty, see README.md and license for details. // // SPDX-License-Identifier: AGPL-3.0-or-later // License-Filename: LICENSES/AGPL-3.0.txt // // Copyright (C) 2019 by via donau // – Österreichische Wasserstraßen-Gesellschaft mbH // Software engineering by Intevation GmbH // // Author(s): // * Sascha L. Teichmann <sascha.teichmann@intevation.de> // * Markus Kottländer <markus.kottlaender@intevation.de> package geoserver import ( "context" "database/sql" "regexp" "strings" "text/template" "gemma.intevation.de/gemma/pkg/auth" "gemma.intevation.de/gemma/pkg/models" ) const ( selectConfigValSQL = ` SELECT config_val FROM sys_admin.system_config WHERE config_key = $1` ) func init() { RegisterStylePreprocessor( "sounding_results_contour_lines_geoserver", templateContourLinesFunc("morphology_classbreaks")) RegisterStylePreprocessor( "sounding_differences", templateContourLinesFunc("morphology_classbreaks_compare")) RegisterStylePreprocessor( "distance_marks_geoserver", templateConfigValues) RegisterStylePreprocessor( "distance_marks_ashore_geoserver", templateConfigValues) RegisterStylePreprocessor( "waterway_area", templateConfigValues) RegisterStylePreprocessor( "waterway_axis", templateConfigValues) // TODO: Add more layers. } func templateConfigValues(tmplTxt string) (string, error) { tmpl, err := template.New("template").Parse(tmplTxt) if err != nil { return "", err } // Try to extract the needed keys from the template. keys := extractKeysFromTemplate(tmplTxt) kv, err := loadConfigValues(keys) if err != nil { return "", err } var buf strings.Builder if err = tmpl.Execute(&buf, kv); err != nil { return "", err } return buf.String(), nil } // TODO: Use the parse tree of the template to extract keys. var findKeysRe = regexp.MustCompile(`{{[-]?\s*\.([^-.\s]+)\s*[-]?}}`) func extractKeysFromTemplate(tmpl string) []string { parts := findKeysRe.FindAllStringSubmatch(tmpl, -1) keys := make(map[string]struct{}) for _, part := range parts { keys[part[1]] = struct{}{} } out := make([]string, len(keys)) var i int for key := range keys { out[i] = key i++ } return out } func loadConfigValues(keys []string) (map[string]string, error) { kv := make(map[string]string, len(keys)) if len(keys) == 0 { return kv, nil } ctx := context.Background() if err := auth.RunAs( ctx, "sys_admin", func(conn *sql.Conn) error { stmt, err := conn.PrepareContext(ctx, selectConfigValSQL) if err != nil { return err } defer stmt.Close() for _, key := range keys { var val string if err := stmt.QueryRowContext(ctx, key).Scan(&val); err != nil { return err } kv[key] = val } return nil }, ); err != nil { return nil, err } return kv, nil } func templateContourLinesFunc(configKey string) func(string) (string, error) { return func(data string) (string, error) { return templateContourLines(data, configKey) } } func templateContourLines(data, configKey string) (string, error) { tmpl, err := template.New("template").Parse(data) if err != nil { return "", err } var cb []models.ClassBreak if cb, err = countourLinesClassBreaks(configKey); err != nil { return "", err } var buf strings.Builder if err = tmpl.Execute(&buf, cb); err != nil { return "", err } return buf.String(), nil } func countourLinesClassBreaks(configKey string) ([]models.ClassBreak, error) { var config string ctx := context.Background() if err := auth.RunAs( ctx, "sys_admin", func(conn *sql.Conn) error { return conn.QueryRowContext( ctx, selectConfigValSQL, configKey, ).Scan(&config) }, ); err != nil { return nil, err } cc, err := models.ParseColorValues(config) if err != nil { return nil, err } return cc.ClassBreaks(), nil }