chore(metadata): improve tabulating for drawing xml tree

combine `xmlns:xmp`, `xmlns:pdf`, `xmlns:dc` into to one `rdf:Description`
foliojs · Jul 6, 2024 · 8dc3ed6 · 8dc3ed6
1 parent 9b3cee4
commit 8dc3ed6
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Showing 5 changed files with 97 additions and 74 deletions.
diff --git a/lib/metadata.js b/lib/metadata.js
@@ -1,25 +1,28 @@
+import { sfix } from "./string"
 
 class PDFMetadata {
     constructor() {
-        this._metadata = `
+        this._metadata = sfix`
         <?xpacket begin="\ufeff" id="W5M0MpCehiHzreSzNTczkc9d"?>
-            <x:xmpmeta xmlns:x="adobe:ns:meta/">
-                <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
+        <x:xmpmeta xmlns:x="adobe:ns:meta/">
+            <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
+
         `;
     }
-    
+
     _closeTags() {
-        this._metadata = this._metadata.concat(`
-                </rdf:RDF>
+        this._metadata = this._metadata.concat(
+            '    </rdf:RDF>\n' +
+            sfix`
             </x:xmpmeta>
-        <?xpacket end="w"?>
-        `);
+            <?xpacket end="w"?>`,
+        );
     }
 
-    append(xml, newline=true) {
-        this._metadata = this._metadata.concat(xml); 
+    append(xml, newline = true) {
+        this._metadata = this._metadata.concat(xml);
         if (newline)
-            this._metadata = this._metadata.concat('\n'); 
+            this._metadata = this._metadata.concat('\n');
     }
 
     getXML() { return this._metadata; }

diff --git a/lib/mixins/metadata.js b/lib/mixins/metadata.js
@@ -1,93 +1,101 @@
 import PDFMetadata from "../metadata"
+import { sfix } from "../string"
 
 export default {
     initMetadata() {
         this.metadata = new PDFMetadata();
     },
 
-    appendXML(xml, newline=true) { this.metadata.append(xml,newline); },
+    appendXML(xml, tabs = 0, newline = true) {
+        tabs += 2
+        xml = xml.split('\n').map(x => ' '.repeat(4).repeat(tabs) + x).join('\n');
+        this.metadata.append(xml, newline);
+    },
 
     _addInfo() {
-        this.appendXML(`
-        <rdf:Description rdf:about="" xmlns:xmp="http://ns.adobe.com/xap/1.0/">
-        `);
-        this.appendXML(`
-            <xmp:CreateDate>${this.info.CreationDate.toISOString().split('.')[0]+"Z"}</xmp:CreateDate>`
+        this.appendXML(
+            sfix`
+            <rdf:Description rdf:about=""
+                    xmlns:xmp="http://ns.adobe.com/xap/1.0/"
+                    xmlns:pdf="http://ns.adobe.com/pdf/1.3/"
+                    xmlns:dc="http://purl.org/dc/elements/1.1/">`,
+            0,
+        );
+        this.appendXML(
+            sfix`
+            <xmp:CreateDate>${this.info.CreationDate.toISOString().split('.')[0] + 'Z'}</xmp:CreateDate>`,
+            1,
         );
         if (this.info.Creator) {
-            this.appendXML(`
-            <xmp:CreatorTool>${this.info.Creator}</xmp:CreatorTool>`
+            this.appendXML(
+                sfix`
+                <xmp:CreatorTool>${this.info.Creator}</xmp:CreatorTool>`,
+                1,
             );
         }
 
-        this.appendXML(`
-        </rdf:Description>
-        `);
-
-        if (this.info.Title || this.info.Author || this.info.Subject) {
-            this.appendXML(`
-            <rdf:Description rdf:about="" xmlns:dc="http://purl.org/dc/elements/1.1/">
-            `);
-
-            if (this.info.Title) {
-                this.appendXML(`
+        if (this.info.Title) {
+            this.appendXML(
+                sfix`
                 <dc:title>
                     <rdf:Alt>
                         <rdf:li xml:lang="x-default">${this.info.Title}</rdf:li>
                     </rdf:Alt>
-                </dc:title>
-                `);
-            }
+                </dc:title>`,
+                1,
+            );
+        }
 
-            if (this.info.Author) {
-                this.appendXML(`
+        if (this.info.Author) {
+            this.appendXML(
+                sfix`
                 <dc:creator>
                     <rdf:Seq>
                         <rdf:li>${this.info.Author}</rdf:li>
                     </rdf:Seq>
-                </dc:creator>
-                `);
-            }
+                </dc:creator>`,
+                1,
+            );
+        }
 
-            if (this.info.Subject) {
-                this.appendXML(`
+        if (this.info.Subject) {
+            this.appendXML(
+                sfix`
                 <dc:description>
                     <rdf:Alt>
                         <rdf:li xml:lang="x-default">${this.info.Subject}</rdf:li>
                     </rdf:Alt>
-                </dc:description>
-                `);
-            }
-
-            this.appendXML(`
-            </rdf:Description>
-            `);
+                </dc:description>`,
+                1,
+            );
         }
 
-        if (this.info.Producer || this.info.Keywords) {
-            this.appendXML(`
-            <rdf:Description rdf:about="" xmlns:pdf="http://ns.adobe.com/pdf/1.3/">
-            `);
-
-            if (this.info.Producer) {
-                this.appendXML(`
-                <pdf:Producer>${this.info.Producer}</pdf:Producer>`, false);
-            }
-
-            if (this.info.Keywords) {
-                this.appendXML(`
-                <pdf:Keywords>${this.info.Keywords}</pdf:Keywords>`, false);
-            }
+        if (this.info.Producer) {
+            this.appendXML(
+                sfix`
+                <pdf:Producer>${this.info.Producer}</pdf:Producer>`,
+                1,
+            );
+        }
 
-            this.appendXML(`
-            </rdf:Description>
-            `);
+        if (this.info.Keywords) {
+            this.appendXML(
+                sfix`
+                <pdf:Keywords>${this.info.Keywords}</pdf:Keywords>`,
+                1,
+            );
         }
+
+        this.appendXML(
+            sfix`
+            </rdf:Description>`,
+            0,
+        );
     },
 
     endMetadata() {
         this._addInfo();
-    
+
         this.metadata.end();
 
         /*

diff --git a/lib/mixins/pdfa.js b/lib/mixins/pdfa.js
@@ -1,4 +1,5 @@
 import fs from 'fs';
+import { sfix } from "../string"
 
 export default {
   initPDFA(pSubset) {
@@ -42,12 +43,11 @@ export default {
   },
 
   _getPdfaid() {
-    return `
-        <rdf:Description xmlns:pdfaid="http://www.aiim.org/pdfa/ns/id/" rdf:about="">
-            <pdfaid:part>${this.subset}</pdfaid:part>
-            <pdfaid:conformance>${this.subset_conformance}</pdfaid:conformance>
-        </rdf:Description>
-        `;
+    return sfix`
+    <rdf:Description xmlns:pdfaid="http://www.aiim.org/pdfa/ns/id/" rdf:about="">
+        <pdfaid:part>${this.subset}</pdfaid:part>
+        <pdfaid:conformance>${this.subset_conformance}</pdfaid:conformance>
+    </rdf:Description>`;
   },
 
   _addPdfaMetadata() {

diff --git a/lib/mixins/pdfua.js b/lib/mixins/pdfua.js
@@ -1,3 +1,4 @@
+import { sfix } from "../string"
 
 export default {
 
@@ -14,11 +15,10 @@ export default {
     },
 
     _getPdfuaid() {
-        return `
+        return sfix`
         <rdf:Description xmlns:pdfuaid="http://www.aiim.org/pdfua/ns/id/" rdf:about="">
             <pdfuaid:part>${this.subset}</pdfuaid:part>
-        </rdf:Description>
-        `;
+        </rdf:Description>`;
     },
 
 }
diff --git a/lib/string.js b/lib/string.js
@@ -0,0 +1,12 @@
+
+export const sfix = (strings, ...expressions) => {
+    const indent = !strings[0].startsWith('\n')
+        ? null
+        : new RegExp(`\n {${strings[0].match(/\n+( *)/)[1].length}}`, 'g');
+    return expressions
+        .reduce(
+            (acc, expr, i) => `${acc}${expr}${strings[i + 1].replace(indent, '\n')}`,
+            strings[0].replace(indent, '\n'),
+        )
+        .replace(/^\n|\n$/g, '');
+};