Added dropdown menu to the example panel (#5898)

* Fix errors in variable names of examples

* Added drop down example

* Added drop down example

* Fixed picture name

* Fixed context variable in purchase order report

docs/docs/extend/plugins/panel.md

@@ -187,9 +187,10 @@ class ExamplePanel(PanelMixin, InvenTreePlugin, UrlsMixin):
     AUTHOR = "Michael"
     DESCRIPTION = "This plugin passes user input from the panel to the plugin"
 
-# Create the panel that will display on every view
+# Create the panel that will display on build detail view
     def get_custom_panels(self, view, request):
         panels = []
+        if isinstance(view, BuildDetail):
 		panels.append({
 		    'title': 'Example Info',
 		    'icon': 'fa-industry',
@@ -221,10 +222,10 @@ Now the html template:
 {% raw %}
 <script>
 async function example_select(){
-    const layernumber = parseInt(document.getElementById("layer_number").value)
+    const layer_number = parseInt(document.getElementById("layer_number").value)
     const size = document.getElementById("string").value
     response = inventreeFormDataUpload(url="{% url 'plugin:examplepanel:transfer' '9999' 'Size' %}"
-                                          .replace("9999", layernumber)
+                                          .replace("9999", layer_number)
                                           .replace("Size", size)
                                       );
 }
@@ -272,7 +273,7 @@ the javascript:
 {% raw %}
 <script>
 async function example_select(){
-    const layernumber = parseInt(document.getElementById("layer_number").value)
+    const layer_number = parseInt(document.getElementById("layer_number").value)
     const size = document.getElementById("string").value
     const cmd_url="{% url 'plugin:examplepanel:transfer' %}";
     data = {
@@ -312,3 +313,42 @@ import json
 The URL and the called function have no parameter names any longer. All data is in the
 request message and can be extracted from this using json.loads. If more data is needed
 just add it to the json container. No further changes are needed. It's really simple :-)
+
+#### Populate a drop down field
+
+Now we add a dropdown menu and fill it with values from the InvenTree database.
+
+{% with id="panel_with_dropwdown", url="plugin/panel_with_dropdown.png", description="Panel with dropdown menu" %}
+{% include "img.html" %}
+{% endwith %}
+
+
+```python
+from company.models import Company
+
+...
+
+    def get_custom_panels(self, view, request):
+        panels = []
+        if isinstance(view, BuildDetail):
+            self.companies=Company.objects.filter(is_supplier=True)
+            panels.append({
+            ...
+```
+Here we create self.companies and fill it with all companies that have the is_supplier flag
+set to true. This is available in the context of the template. A drop down menu can be created
+by looping.
+
+
+```html
+{% raw %}
+<select id="ems">
+    {% for company in plugin.companies %}
+	<option value="{{ company.id }}"> {{ company.name }} </option>
+    {% endfor %}
+</select>
+{% endraw %}
+```
+
+The value of the select is the pk of the company. It can simply be added to the
+json container and transferred to the plugin.

docs/docs/report/purchase_order.md

@@ -37,8 +37,7 @@ Each line item have sub variables, as follows:
 | Variable | Description |
 | --- | --- |
 | quantity | The quantity of the part to be ordered |
-| part | The supplier part to be ordered |
+| part | The [supplierpart ](./context_variables.md#supplierpart) object to be ordered |
-| part | The [supplierpart ](./context_variables.md#supplierpart) object that the build references |
 | reference | The reference given in the part of the order |
 | notes | The notes given in the part of the order |
 | target_date | The date when the part should arrive. Each part can have an individual date |