Refactoring: automatically generate code files from layer/theme files to avoid using 'Eval'

scripts/generateLayerOverview.ts

@@ -21,6 +21,7 @@ import { Utils } from "../src/Utils"
 import Script from "./Script"
 import { AllSharedLayers } from "../src/Customizations/AllSharedLayers"
 import { parse as parse_html } from "node-html-parser"
+import { ExtraFunctions } from "../src/Logic/ExtraFunctions"
 // This scripts scans 'src/assets/layers/*.json' for layer definition files and 'src/assets/themes/*.json' for theme definition files.
 // It spits out an overview of those to be used to load them
 
@@ -395,10 +396,129 @@ class LayerOverviewUtils extends Script {
                 skippedLayers.length +
                 " layers"
         )
+        // We always need the calculated tags of 'usersettings', so we export them separately
+        this.extractJavascriptCodeForLayer(
+            state.sharedLayers.get("usersettings"),
+            "./src/Logic/State/UserSettingsMetaTagging.ts"
+        )
 
         return sharedLayers
     }
 
+    /**
+     * Given: a fully expanded themeConfigJson
+     *
+     * Will extract a dictionary of the special code and write it into a javascript file which can be imported.
+     * This removes the need for _eval_, allowing for a correct CSP
+     * @param themeFile
+     * @private
+     */
+    private extractJavascriptCode(themeFile: LayoutConfigJson) {
+        const allCode = [
+            "import {Feature} from 'geojson'",
+            'import { ExtraFuncType } from "../../../Logic/ExtraFunctions";',
+            'import { Utils } from "../../../Utils"',
+            "export class ThemeMetaTagging {",
+            "   public static readonly themeName = " + JSON.stringify(themeFile.id),
+            "",
+        ]
+        for (const layer of themeFile.layers) {
+            const l = <LayerConfigJson>layer
+            const code = l.calculatedTags ?? []
+
+            allCode.push(
+                "   public metaTaggging_for_" +
+                    l.id +
+                    "(feat: Feature, helperFunctions: Record<ExtraFuncType, (feature: Feature) => Function>) {"
+            )
+            allCode.push("      const {" + ExtraFunctions.types.join(", ") + "} = helperFunctions")
+            for (const line of code) {
+                const firstEq = line.indexOf("=")
+                let attributeName = line.substring(0, firstEq).trim()
+                const expression = line.substring(firstEq + 1)
+                const isStrict = attributeName.endsWith(":")
+                if (!isStrict) {
+                    allCode.push(
+                        "      Utils.AddLazyProperty(feat.properties, '" +
+                            attributeName +
+                            "', () => " +
+                            expression +
+                            " ) "
+                    )
+                } else {
+                    attributeName = attributeName.substring(0, attributeName.length - 2).trim()
+                    allCode.push("      feat.properties['" + attributeName + "'] = " + expression)
+                }
+            }
+            allCode.push("   }")
+        }
+
+        const targetDir = "./src/assets/generated/metatagging/"
+        if (!existsSync(targetDir)) {
+            mkdirSync(targetDir)
+        }
+        allCode.push("}")
+
+        writeFileSync(targetDir + themeFile.id + ".ts", allCode.join("\n"))
+    }
+
+    private extractJavascriptCodeForLayer(l: LayerConfigJson, targetPath?: string) {
+        let importPath = "../../../"
+        if (targetPath) {
+            const l = targetPath.split("/")
+            if (l.length == 1) {
+                importPath = "./"
+            } else {
+                importPath = ""
+                for (let i = 0; i < l.length - 3; i++) {
+                    const _ = l[i]
+                    importPath += "../"
+                }
+            }
+        }
+        const allCode = [
+            `import { Utils } from "${importPath}Utils"`,
+            `/** This code is autogenerated - do not edit. Edit ./assets/layers/${l.id}/${l.id}.json instead */`,
+            "export class ThemeMetaTagging {",
+            "   public static readonly themeName = " + JSON.stringify(l.id),
+            "",
+        ]
+        const code = l.calculatedTags ?? []
+
+        allCode.push(
+            "   public metaTaggging_for_" + l.id + "(feat: {properties: Record<string, string>}) {"
+        )
+        for (const line of code) {
+            const firstEq = line.indexOf("=")
+            let attributeName = line.substring(0, firstEq).trim()
+            const expression = line.substring(firstEq + 1)
+            const isStrict = attributeName.endsWith(":")
+            if (!isStrict) {
+                allCode.push(
+                    "      Utils.AddLazyProperty(feat.properties, '" +
+                        attributeName +
+                        "', () => " +
+                        expression +
+                        " ) "
+                )
+            } else {
+                attributeName = attributeName.substring(0, attributeName.length - 2).trim()
+                allCode.push("      feat.properties['" + attributeName + "'] = " + expression)
+            }
+        }
+        allCode.push("   }")
+        allCode.push("}")
+
+        const targetDir = "./src/assets/generated/metatagging/"
+        if (!targetPath) {
+            if (!existsSync(targetDir)) {
+                mkdirSync(targetDir)
+            }
+        }
+
+        writeFileSync(targetPath ?? targetDir + "layer_" + l.id + ".ts", allCode.join("\n"))
+    }
+
     private buildThemeIndex(
         licensePaths: Set<string>,
         sharedLayers: Map<string, LayerConfigJson>,
@@ -436,6 +556,7 @@ class LayerOverviewUtils extends Script {
         })
 
         const skippedThemes: string[] = []
+
         for (let i = 0; i < themeFiles.length; i++) {
             const themeInfo = themeFiles[i]
             const themePath = themeInfo.path
@@ -443,6 +564,7 @@ class LayerOverviewUtils extends Script {
 
             const targetPath =
                 LayerOverviewUtils.themePath + "/" + themePath.substring(themePath.lastIndexOf("/"))
+
             const usedLayers = Array.from(
                 LayerOverviewUtils.extractLayerIdsFrom(themeFile, false)
             ).map((id) => LayerOverviewUtils.layerPath + id + ".json")
@@ -504,6 +626,8 @@ class LayerOverviewUtils extends Script {
 
                 this.writeTheme(themeFile)
                 fixed.set(themeFile.id, themeFile)
+
+                this.extractJavascriptCode(themeFile)
             } catch (e) {
                 console.error("ERROR: could not prepare theme " + themePath + " due to " + e)
                 throw e