Demonstrates how to insert a header in the document. - Shared with Script Lab

Insert header.yaml

name: Insert header
description: Demonstrates how to insert a header in the document.
author: JuaneloJuanelo
host: WORD
api_set: {}
script:
    content: |-
        $("#run").click(run);
        $("#run").click(() => tryCatch(run));

        async function run() {
            await Word.run(async (context) => {
                // Headers and footers belong to sections
                // so in order to insert a header/footer we must  obtain a section first
                // then we have access to the "body" of the header/footer.
                context.document.sections.getFirst()
                    .getHeader("primary").insertText("This is a header", "start");

                await context.sync();
            })
        }

        /** Default helper for invoking an action and handling errors. */
        async function tryCatch(callback) {
            try {

                await callback();
            }
            catch (error) {
                OfficeHelpers.UI.notify(error);
                OfficeHelpers.Utilities.log(error);
            }
        }
    language: typescript
template:
    content: |-
        <p class="ms-font-m">Click to insert a header in the document</p>
        <button id="run" class="ms-Button">
            <span class="ms-Button-label">Insert header</span>
        </button>
    language: html
style:
    content: |-
        body {
            margin: 0;
            padding: 10px;
        }


        /* Button customization, including overwriting some Fabric defaults */

        .ms-Button, .ms-Button:focus {
            background: #2b579a;
            border: #2b579a;
        }

            .ms-Button > .ms-Button-label,
            .ms-Button:focus > .ms-Button-label,
            .ms-Button:hover > .ms-Button-label {
                color: white;
            }

            .ms-Button:hover, .ms-Button:active {
                background: #204072;
            }

            .ms-Button.is-disabled, .ms-Button:disabled {
                background-color: #f4f4f4;
                border-color: #f4f4f4;
            }

            .ms-Button.is-disabled .ms-Button-label,
            .ms-Button:disabled .ms-Button-label {
                color: #a6a6a6;
            }
    language: css
libraries: |-
    // Office.js
    https://appsforoffice.microsoft.com/lib/1/hosted/office.js

    // NPM libraries
    jquery@3.1.1
    office-ui-fabric-js@1.4.0/dist/js/fabric.min.js
    office-ui-fabric-js@1.4.0/dist/css/fabric.min.css
    office-ui-fabric-js@1.4.0/dist/css/fabric.components.min.css
    @microsoft/office-js-helpers@0.7.4/dist/office.helpers.min.js
    core-js@2.4.1/client/core.min.js

    // IntelliSense: Use dt~library_name for DefinitelyTyped or URLs to d.ts files
    @types/office-js
    @types/jquery
    @types/core-js
    @microsoft/office-js-helpers@0.7.4/dist/office.helpers.d.ts