styles: support for external styles. parsing external styles.

src/file/styles/external-styles-factory.ts

@@ -0,0 +1,64 @@
+import { Styles } from "./";
+import * as fastXmlParser from "fast-xml-parser";
+import { ImportedXmlComponent, ImportedRootElementAttributes } from "./../../file/xml-components";
+
+const parseOptions = {
+    ignoreAttributes: false,
+    attributeNamePrefix: "",
+    attrNodeName: "_attr",
+};
+
+export class ExternalStylesFactory {
+    /**
+     * Creates new Style based on the given styles.
+     * Parses the styles and convert them to XmlComponent.
+     * Example content from styles.xml:
+     * <?xml version="1.0">
+     * <w:styles xmlns:mc="some schema" ...>
+     *
+     *   <w:style w:type="paragraph" w:styleId="Heading1">
+     *           <w:name w:val="heading 1"/>
+     *           .....
+     *   </w:style>
+     *
+     *   <w:style w:type="paragraph" w:styleId="Heading2">
+     *           <w:name w:val="heading 2"/>
+     *           .....
+     *   </w:style>
+     *
+     *   <w:docDefaults>Or any other element will be parsed to</w:docDefaults>
+     *
+     * </w:styles>
+     * @param externalStyles context from styles.xml
+     */
+    public newInstance(externalStyles: string): Styles {
+        const xmlStyles = fastXmlParser.parse(externalStyles, parseOptions)["w:styles"];
+        // create styles with attributes from the parsed xml
+        const importedStyle = new Styles(new ImportedRootElementAttributes(xmlStyles._attr));
+
+        // convert other elements (not styles definitions, but default styles and so on ...)
+        Object.keys(xmlStyles)
+            .filter((element) => element !== "_attr" && element !== "w:style")
+            .forEach((element) => {
+                importedStyle.push(new ImportedXmlComponent(element, xmlStyles[element]._attr));
+            });
+
+        // convert the styles one by one
+        xmlStyles["w:style"]
+            .map((style) => this.convertElement("w:style", style))
+            .forEach(importedStyle.push.bind(importedStyle));
+
+        return importedStyle;
+    }
+
+    convertElement(elementName: string, element: any): ImportedXmlComponent {
+        const xmlElement = new ImportedXmlComponent(elementName, element._attr);
+        if (typeof element === "object") {
+            Object.keys(element)
+                .filter((key) => key !== "_attr")
+                .map((item) => this.convertElement(item, element[item]))
+                .forEach(xmlElement.push.bind(xmlElement));
+        }
+        return xmlElement;
+    }
+}