Clarify v-html usage (vuejs#905)

lloy0076 · chrisvfritz · commit 84a65b1001d5 · 2017-05-18T20:40:28.000-04:00
* Update syntax.md


Originally, I'd thought that:

```
&lt;div v-html="rawHtml"&gt;This {{ some_html}}&lt;/div&gt;
```

(where we might have `vm.data.some_html='&lt;b&gt;hello&lt;/b&gt;'`) ... would render something like:

**hello**

But instead we get:

```
Property or method "rawHtml" is not defined on the instance but referenced during render. Make sure to declare reactive data properties in the data option.
```

...if one is watching console errors.

My wording could be a little bit kludgy and others might be able to make it clearer but I think this may overcome some misunderstandings for those not familiar with vuejs.

* Update syntax.md
diff --git a/src/v2/guide/syntax.md b/src/v2/guide/syntax.md
@@ -36,7 +36,7 @@ The double mustaches interprets the data as plain text, not HTML. In order to ou
 <div v-html="rawHtml"></div>
 ```
 
-The contents are inserted as plain HTML - data bindings are ignored. Note that you cannot use `v-html` to compose template partials, because Vue is not a string-based templating engine. Instead, components are preferred as the fundamental unit for UI reuse and composition.
+The contents of this `div` will be replaced with the value of the `rawHtml` property, interpreted as plain HTML - data bindings are ignored. Note that you cannot use `v-html` to compose template partials, because Vue is not a string-based templating engine. Instead, components are preferred as the fundamental unit for UI reuse and composition.
 
 <p class="tip">Dynamically rendering arbitrary HTML on your website can be very dangerous because it can easily lead to [XSS vulnerabilities](https://en.wikipedia.org/wiki/Cross-site_scripting). Only use HTML interpolation on trusted content and **never** on user-provided content.</p>
 
