Class HtmlOutput

HtmlOutput

An HtmlOutput object that can be served from a script. Due to security considerations, scripts cannot directly return HTML to a browser. Instead, they must sanitize it so that it cannot perform malicious actions. You can return sanitized HTML like this:

function doGet() {
  return HtmlService.createHtmlOutput('<b>Hello, world!</b>');
}

The code in the HtmlOutput can include embedded JavaScript and CSS. (This is standard client-side JavaScript that manipulates the DOM, not Apps Script). All of this content is sandboxed using iframe sandboxing. For more information, see the guide to restrictions in HTML service.

Methods

Method	Return type	Brief description
addMetaTag(name, content)	HtmlOutput	Adds a meta tag to the page.
append(addedContent)	HtmlOutput	Appends new content to the content of this HtmlOutput.
appendUntrusted(addedContent)	HtmlOutput	Appends new content to the content of this HtmlOutput, using contextual escaping.
asTemplate()	HtmlTemplate	Returns an HtmlTemplate backed by this HtmlOutput.
clear()	HtmlOutput	Clears the current content.
getAs(contentType)	Blob	Return the data inside this object as a blob converted to the specified content type.
getBlob()	Blob	Return the data inside this object as a blob.
getContent()	String	Gets the content of this HtmlOutput.
getFaviconUrl()	String	Gets the URL for a favicon link tag added to the page by calling setFaviconUrl(iconUrl).
getHeight()	Integer	Gets the initial height of the custom dialog in Google Docs, Sheets, or Forms.
getMetaTags()	HtmlOutputMetaTag[]	Gets an array of objects that represent meta tags added to the page by calling addMetaTag(name, content).
getTitle()	String	Gets the title of the output page.
getWidth()	Integer	Gets the initial width of the custom dialog in Google Docs, Sheets, or Forms.
setContent(content)	HtmlOutput	Sets the content of this HtmlOutput.
setFaviconUrl(iconUrl)	HtmlOutput	Adds a link tag for a favicon to the page.
setHeight(height)	HtmlOutput	Sets the initial height of the custom dialog in Google Docs, Sheets, or Forms.
setSandboxMode(mode)	HtmlOutput	This method now has no effect — previously it set the sandbox mode used for client-side scripts.
setTitle(title)	HtmlOutput	Sets the title of the output page.
setWidth(width)	HtmlOutput	Sets the initial width of a custom dialog in Google Docs, Sheets, or Forms.
setXFrameOptionsMode(mode)	HtmlOutput	Sets the state of the page's X-Frame-Options header, which controls clickjacking prevention.

Detailed documentation

addMetaTag(name, content)

Adds a meta tag to the page. Meta tags included directly in an Apps Script HTML file are ignored. Only the following meta tags are allowed:

<meta name="apple-mobile-web-app-capable" content="..."/>
<meta name="google-site-verification" content="..."/>
<meta name="mobile-web-app-capable" content="..."/>
<meta name="viewport" content="..."/>

const output = HtmlService.createHtmlOutput('<b>Hello, world!</b>');
output.addMetaTag('viewport', 'width=device-width, initial-scale=1');

Parameters

Name	Type	Description
name	String	The value of the meta tag's name attribute.
content	String	The value of the meta tag's content attribute.

Return

HtmlOutput — This output, for chaining.

---

append(addedContent)

Appends new content to the content of this HtmlOutput. Use this only for content from a trusted source, because it is not escaped.

// Log "<b>Hello, world!</b><p>Hello again, world.</p>"
const output = HtmlService.createHtmlOutput('<b>Hello, world!</b>');
output.append('<p>Hello again, world.</p>');
Logger.log(output.getContent());

Parameters

Name	Type	Description
addedContent	String	The content to append.

Return

HtmlOutput — This output, for chaining.

Throws

Error — if the HTML is malformed

See also

• appendUntrusted(addedContent)

---

appendUntrusted(addedContent)

Appends new content to the content of this HtmlOutput, using contextual escaping.

This method correctly escapes content based on the current state of the HtmlOutput, so that the result is a safe string with no markup or side affects. Use this instead of using append whenever you are adding content from an untrusted source, such as from a user, to avoid accidentally allowing a cross site scripting (XSS) bug where content or markup that you append causes unexpected code execution.

// Log "<b>Hello, world!</b>&lt;p&gt;Hello again, world.&lt;/p&gt;"
const output = HtmlService.createHtmlOutput('<b>Hello, world!</b>');
output.appendUntrusted('<p>Hello again, world.</p>');
Logger.log(output.getContent());

Parameters

Name	Type	Description
addedContent	String	The content to append.

Return

HtmlOutput — This output, for chaining.

Throws

Error — if the HTML is very malformed

See also

• append(addedContent)

---

asTemplate()

Returns an HtmlTemplate backed by this HtmlOutput. This method can be used to build up a template incrementally. Future changes to HtmlOutput affect the contents of the HtmlTemplate as well.

const output = HtmlService.createHtmlOutput('<b>Hello, world!</b>');
const template = output.asTemplate();

Return

HtmlTemplate — The new HtmlTemplate.

---

clear()

Clears the current content.

const output = HtmlService.createHtmlOutput('<b>Hello, world!</b>');
output.clear();

Return

HtmlOutput — This output, for chaining.

---

getAs(contentType)

Return the data inside this object as a blob converted to the specified content type. This method adds the appropriate extension to the filename—for example, "myfile.pdf". However, it assumes that the part of the filename that follows the last period (if any) is an existing extension that should be replaced. Consequently, "ShoppingList.12.25.2014" becomes "ShoppingList.12.25.pdf".

To view the daily quotas for conversions, see Quotas for Google Services. Newly created Google Workspace domains might be temporarily subject to stricter quotas.

Parameters

Name	Type	Description
contentType	String	The MIME type to convert to. For most blobs, 'application/pdf' is the only valid option. For images in BMP, GIF, JPEG, or PNG format, any of 'image/bmp', 'image/gif', 'image/jpeg', or 'image/png' are also valid. For a Google Docs document, 'text/markdown' is also valid.

Return

Blob — The data as a blob.

---

getBlob()

Return the data inside this object as a blob.

Return

Blob — The data as a blob.

---

getContent()

Gets the content of this HtmlOutput.

// Log "<b>Hello, world!</b>"
const output = HtmlService.createHtmlOutput('<b>Hello, world!</b>');
Logger.log(output.getContent());

Return

String — The content that is served.

---

getFaviconUrl()

Gets the URL for a favicon link tag added to the page by calling setFaviconUrl(iconUrl). Favicon link tags included directly in an Apps Script HTML file are ignored.

const output = HtmlService.createHtmlOutput('<b>Hello, world!</b>');
output.setFaviconUrl('http://www.example.com/image.png');
Logger.log(output.getFaviconUrl());

Return

String — The URL of the favicon image.

---

getHeight()

Gets the initial height of the custom dialog in Google Docs, Sheets, or Forms. If the HtmlOutput is published as a web app instead, this method returns null. To resize a dialog that is already open, call google.script.host.setHeight(height) in client-side code.

const output = HtmlService.createHtmlOutput('<b>Hello, world!</b>');
output.setHeight(200);
Logger.log(output.getHeight());

Return

Integer — The height, in pixels.

---

getMetaTags()

Gets an array of objects that represent meta tags added to the page by calling addMetaTag(name, content). Meta tags included directly in an Apps Script HTML file are ignored.

const output = HtmlService.createHtmlOutput('<b>Hello, world!</b>');
output.addMetaTag('viewport', 'width=device-width, initial-scale=1');

const tags = output.getMetaTags();
Logger.log(
    '<meta name="%s" content="%s"/>',
    tags[0].getName(),
    tags[0].getContent(),
);

Return

HtmlOutputMetaTag[] — An array of objects that represent meta tags added to the page by calling addMetaTag(name, content).

---

getTitle()

Gets the title of the output page. Note that the <title> HTML element is ignored.

const output = HtmlService.createHtmlOutput('<b>Hello, world!</b>');
Logger.log(output.getTitle());

Return

String — The title of the page.

---

getWidth()

Gets the initial width of the custom dialog in Google Docs, Sheets, or Forms. If the HtmlOutput is published as a web app instead, this method returns null. To resize a dialog that is already open, call google.script.host.setWidth(width) in client-side code.

const output = HtmlService.createHtmlOutput('<b>Hello, world!</b>');
output.setWidth(200);
Logger.log(output.getWidth());

Return

Integer — The width in pixels.

---

setContent(content)

Sets the content of this HtmlOutput.

const output = HtmlService.createHtmlOutput();
output.setContent('<b>Hello, world!</b>');

Parameters

Name	Type	Description
content	String	The content to serve.

Return

HtmlOutput — This output, for chaining.

Throws

Error — if the HTML is malformed

---

setFaviconUrl(iconUrl)

Adds a link tag for a favicon to the page. Favicon link tags included directly in an Apps Script HTML file are ignored.

const output = HtmlService.createHtmlOutput('<b>Hello, world!</b>');
output.setFaviconUrl('http://www.example.com/image.png');

Parameters

Name	Type	Description
iconUrl	String	The URL of the favicon image, with the image extension indicating the image type.

Return

HtmlOutput — This output, for chaining.

---

setHeight(height)

Sets the initial height of the custom dialog in Google Docs, Sheets, or Forms. If the HtmlOutput is published as a web app instead, this method has no effect. To resize a dialog that is already open, call google.script.host.setHeight(height) in client-side code.

const output = HtmlService.createHtmlOutput('<b>Hello, world!</b>');
output.setHeight(200);

Parameters

Name	Type	Description
height	Integer	The new height in pixels; null results in a default value.

Return

HtmlOutput — This output, for chaining.

---

setSandboxMode(mode)

This method now has no effect — previously it set the sandbox mode used for client-side scripts. To protect users from being served malicious HTML or JavaScript, client-side code served from HTML service executes in a security sandbox that imposes restrictions on the code. Originally this method allowed script authors to choose between different versions of the sandbox, but now all scripts now use IFRAME mode regardless of what sandbox mode is set. For more information, see the guide to restrictions in HTML service.

The IFRAME mode imposes many fewer restrictions than the other sandbox modes and runs fastest, but does not work at all in certain older browsers, including Internet Explorer 9. The sandbox mode can be read in a client-side script by inspecting google.script.sandbox.mode. Note that this property returns the actual mode on the client, which may differ from the mode requested on the server if the requested mode is not supported in the user's browser.

<!-- Read the sandbox mode (in a client-side script). -->
<script>
  alert(google.script.sandbox.mode);
</script>

Parameters

Name	Type	Description
mode	SandboxMode	The sandbox mode to use.

Return

HtmlOutput — This output, for chaining.

---

setTitle(title)

Sets the title of the output page. For web apps, this is the title of the entire page, while for HtmlOutput shown in Google Sheets, this is the dialog title.

const output = HtmlService.createHtmlOutput('<b>Hello, world!</b>');
output.setTitle('My First Page');

Parameters

Name	Type	Description
title	String	The new title.

Return

HtmlOutput — This output, for chaining.

---

setWidth(width)

Sets the initial width of a custom dialog in Google Docs, Sheets, or Forms. If the HtmlOutput is published as a web app instead, this method has no effect. To resize a dialog that is already open, call google.script.host.setWidth(width) in client-side code.

const output = HtmlService.createHtmlOutput('<b>Hello, world!</b>');
output.setWidth(200);

Parameters

Name	Type	Description
width	Integer	The new width in pixels; null results in a default value.

Return

HtmlOutput — This output, for chaining.

---

setXFrameOptionsMode(mode)

Sets the state of the page's X-Frame-Options header, which controls clickjacking prevention.

Setting XFrameOptionsMode.ALLOWALL lets any site iframe the page, so the developer should implement their own protection against clickjacking.

If a script does not set an X-Frame-Options mode, Apps Script uses XFrameOptionsMode.DEFAULT mode as the default.

// Serve HTML with no X-Frame-Options header (in Apps Script server-side code).
const output = HtmlService.createHtmlOutput('<b>Hello, world!</b>');
output.setXFrameOptionsMode(HtmlService.XFrameOptionsMode.ALLOWALL);

Parameters

Name	Type	Description
mode	XFrameOptionsMode	The XFrame options mode to set.

Return

HtmlOutput — This output, for chaining.