er-nodejs-pptx/lib/helpers/pptx-content-helper.js

Generate PPTX files on the server-side with JavaScript.

/* eslint-disable no-prototype-builtins */

class PptxContentHelper {
    // Given the "content" block from the root (ex: PowerPointFactory.content), this function will pull out every slide and return very basic info on them.
    // (Right now, it's just the slide layout name used on each slide and the relId for that layout-to-slide relationship.)
    static extractInfoFromSlides(content) {
        let slideInformation = {}; // index is slide name

        for (let key in content) {
            if (key.substr(0, 16) === 'ppt/slides/slide') {
                let slideName = key.substr(11, key.lastIndexOf('.') - 11);
                let slideRelsKey = `ppt/slides/_rels/${slideName}.xml.rels`;
                let slideLayoutRelsNode = content[slideRelsKey]['Relationships']['Relationship'].filter(function(element) {
                    return element['$']['Type'] === 'http://schemas.openxmlformats.org/officeDocument/2006/relationships/slideLayout';
                })[0];

                let relId = slideLayoutRelsNode['$'].Id;
                let target = slideLayoutRelsNode['$'].Target;
                let layout = target.substr(target.lastIndexOf('/') + 1);
                layout = layout.substr(0, layout.indexOf('.'));

                let objectInfo = PptxContentHelper.extractSlideObjectInfo(content, slideName);

                slideInformation[slideName] = { layout: { relId: relId, name: layout }, objectCount: objectInfo.objectCount };
            }
        }

        return slideInformation;
    }

    static extractSlideObjectInfo(content, slideName) {
        let objectInfo = {
            objectCount: 0,
        };

        // TODO... Mark: you can add code here...

        return objectInfo;
    }

    static extractNodes(contentBlock) {
        let existingNodes = [];

        for (let key in contentBlock) {
            if (contentBlock.hasOwnProperty(key)) {
                existingNodes.push({ key: key, node: contentBlock[key] });
                delete contentBlock[key];
            }
        }

        return existingNodes;
    }

    static restoreNodes(contentBlock, nodes) {
        for (let i = 0; i < nodes.length; i++) {
            contentBlock[nodes[i].key] = nodes[i].node;
        }
    }
}

module.exports.PptxContentHelper = PptxContentHelper;